903.3 Warning Signs and Object Markers (MUTCD Chapter 2C)

903.3.1 Application of Warning Signs (MUTCD Section 2C.01)

Standard. The use of warning signs shall be based on an engineering study or on engineering judgment.

Warning signs shall be retroreflective.

Guidance. The use of warning signs should be kept to a minimum as the unnecessary use of warning signs tends to breed disrespect for all signs. In situations where the condition or activity is seasonal or temporary, the warning sign should be removed or covered when the condition or activity does not exist.

Support. The decision to use most warning signs is based on prevailing conditions. The items to be considered when determining the need for a warning sign are stopping sight distance and prevailing speed. Prevailing speed is determined by using either the posted or 85th percentile speed on the facility. Stopping sight distance is the distance a driver requires to perceive, react, and respond to a condition. The prevailing speed affects the amount of sight distance required for a condition.

It is recommended to use Table 903.3.1 to determine the stopping sight distance needed when considering the use of most warning signs. If the stopping sight distance is less than that in Table 903.3.1, a sign might be needed.

**Table 903.3.1** Stopping Sight Distance Requirements
Prevailing Speed (mph)	Distance (ft.)
30	200
35	250
40	305
45	360
50	425
55	495
60	570
65	645
70	730
Note: Based on "A Policy on Geometric Design of Highways and Streets", 2018 Edition, AASHTO, Table 3-1, Stopping Sight Distance

903.3.2 Design of Warning Signs (MUTCD Section 2C.02)

Standard. Except as provided in the following Option paragraph or unless specifically designated otherwise, all warning signs shall be diamond-shaped (square with one diagonal vertical) with a black legend and border on a fluorescent yellow background. Warning signs shall be designed in accordance with the sizes, shapes, colors, and legends contained in the FHWA “Standard Highway Signs” publication (see EPG 911 (MUTCD Section 1A.05)).

Option. A warning sign that is larger than the size shown in the Oversized column in Table 903.3.3 for that particular sign may be diamond-shaped or may be rectangular or square in shape.

Support. The use of a shape other than diamond-shaped is typical for overhead installations. EPG 903.1.5 contains information on allowable methods to accommodate a diamond-shaped warning sign where the lateral space available in which to install a diamond-shaped warning sign is constrained, such as in urban locations, when mounting on a narrow median barrier or adjacent to a retaining wall, including the display of the standard legend in a vertically oriented rectangle.

The use of LEDs in the border and legend of warning signs is described in EPG 903.1.12.

Option. Word message warning signs other than those provided in the EPG may be developed and installed by MoDOT for conditions otherwise not addressed by standard signs (see EPG 903.1.4).

Support. MoDOT uses the fluorescent yellow-green (FYG) color exclusively for school signs. The only application where MoDOT would use the FYG color for bicycle or pedestrian signs is if a state route and local street intersected and the local jurisdiction utilized FYG color signs on their legs of the intersection. This would only be done to be in compliance with the MUTCD requirement that FYG and yellow shall not be intermixed in an application.

There are two primary reasons MoDOT has chosen not to use FYG color for bicycle or pedestrian signs. The first reason involves the MUTCD requirement that FYG color signs shall not be intermixed with other yellow color signs. A transition to FYG color signs would result in the premature replacement of all signs in an area when just one sign reached the end of its life or was damaged, resulting in wasted resources. The second reason, and most important, is to reserve FYG color signs for school signing to make these signs stand out from other signing, as school children are especially vulnerable road users.

In response to repeated requests by a local jurisdiction for MoDOT to use the FYG color for bicycle and pedestrian signs, MoDOT initiated a research study to determine if there were any documented safety benefits for using the FYG color for these signs. Having previously adopted fluorescent orange for all work zone signs, MoDOT made the transition from standard yellow to fluorescent yellow (FY) for all warning signs as there was documentation to support this change in sheeting color. However, no documentation could be found to indicate that the FYG sign color provides any safety benefits when compared to the FY sign color. The research study surveyed other state DOTs as well as local MPOs to determine if they made a change to the FYG color, how they made the decision to do so, and if they could provide any research documentation which would support FYG to be safer than FY. The study showed there was no conclusive evidence to demonstrate that FYG sign color had any safety benefit compared to the FY sign color that MoDOT was already using. Most agencies who adopted FYG did so based on engineering judgement and not based on the results of research.

Standard. Warning signs regarding conditions associated with school buses and schools and their related supplemental plaques shall have a black legend and border on a fluorescent yellow-green background (see EPG 908.2.1).

Option. Consistent with the provisions of EPG 902.18.3, a Warning Beacon may be used in combination with a standard warning sign.

903.3.3 Size of Warning Signs and Plaques (MUTCD Section 2C.03)

Standard. Except as provided in EPG 903.1.7, the sizes for warning signs shall be as shown in Table 903.3.3.

Support. EPG 903.1.7 contains information regarding the applicability of the various columns in Table 903.3.3.

Option. Signs and plaques larger than those shown in Table 903.3.3 may be used (see EPG 903.1.11) for special applications where speed, volume or other factors result in conditions where increased emphasis, improved recognition or increased legibility would be desirable, with approval from the MoDOT Highway Safety and Traffic Division.

Guidance. The minimum size for all diamond-shaped warning signs facing traffic on exit and entrance ramps at interchanges should be the size identified in Table 903.3.3 for the mainline roadway classification (Freeway/Expressway).

Table 903.3.3 Warning Sign and Plaques Sizes
Sign or Plaque	Sign Designation	EPG Article	Conventional Road (in. x in.)		Freeway/Expressway (in. x in.)
Sign or Plaque	Sign Designation	EPG Article	Standard	Oversized	Mainline & Ramps
Turn	W1-1	903.3.7	36 X 36	48 X 48	48 X 48
Curve	W1-2	903.3.7	36 X 36	48 X 48	48 X 48
Reverse Turn	W1-3	903.3.7	36 X 36	48 X 48	48 X 48
Reverse Curve	W1-4	903.3.7	36 X 36	48 X 48	48 X 48
Winding Road	W1-5	903.3.7	36 X 36	48 X 48	48 X 48
One-Direction Large Arrow	W1-6	903.3.10	48 X 24	72 X 36	72 X 36
Two-Direction Large Arrow	W1-7	903.3.35	48 X 24	72 X 36	72 X 36
Chevron	W1-8	903.3.8	18 X 24	30 X 36	30 X 36
Combination Horizontal Alignment/Intersection	W1-10 Series	903.3.9	36 X 36	48 X 48	48 X 48
Hairpin Curve	W1-11	903.3.7	36 X 36	48 X 48	48 X 48
Truck Rollover	W1-13	903.3.11	-	-	48 X 48
270° Curve	W1-15	903.3.7	-	-	48 X 48
Cross road	W2-1	903.3.33	36 X 36	48 X 48	48 X 48
Side Road	W2-2	903.3.33	36 X 36	48 X 48	48 X 48
Side Road (45°)	W2-3, 3a	903.3.33	36 X 36	48 X 48	48 X 48
T Intersection	W2-4	903.3.33	36 X 36	48 X 48	48 X 48
Y Intersection	W2-5	903.3.33	36 X 36	48 X 48	48 X 48
Circular Intersection	W2-6	903.3.33	36 X 36	48 X 48	48 X 48
Offset Side Road	W2-7	903.3.33	36 X 36	48 X 48	48 x 48
Double Side Roads	W2-8	903.3.33	36 X 36	48 X 48	48 X 48
Watch for Entering Traffic	W2-10a	903.3.34	36 X 36	48 X 48	48 X 48
Watch for Approaching Traffic	W2-11a	903.3.34	36 X 36	48 X 48	48 X 48
Stop Ahead	W3-1	903.3.29	36 X 36	48 X 48	48 X 48
Yield Ahead	W3-2	903.3.29	36 X 36	48 X 48	48 X 48
Signal Ahead	W3-3	903.3.29	36 X 36	48 X 48	48 X 48
Be Prepared to Stop	W3-4	903.3.29	36 X 36	48 X 48	48 X 48
Reduced Speed Ahead	W3-5	903.3.32	36 X 36	48 X 48	48 X 48
Ramp Meter Ahead	W3-7	903.3.30	36 X 36	-	-
Ramp Metered When Flashing	W3-8	903.3.30	36 X 36	-	-
Ferry Crossing Ahead	W3-18	903.3.54	36 X 36	48 X 48	-
Merge	W4-1	903.3.37	36 X 36	48 X 48	48 X 48
Lane Ends	W4-2	903.3.39	36 X 36	48 X 48	48 X 48
Added Lane	W4-3	903.3.38	36 X 36	48 X 48	48 X 48
Cross Traffic Does Not Stop (plaque)	W4-4P	903.3.65	24 X 12	36 X 18	36 X 18
Traffic From Left Does Not Stop (plaque)	W4-4aPL	903.3.65	24 X 12	36 X 18	36 X 18
Traffic From Right Does Not Stop (plaque)	W4-4aPR	903.3.65	24 X 12	36 X 18	36 X 18
Oncoming Traffic Does Not Stop (plaque)	W4-4bP	903.3.65	24 X 12	36 X 18	36 X 18
Entering Roadway Merge	W4-5	903.3.37	36 X 36	48 X 48	48 X 48
Entering Roadway Added Lane	W4-6	903.3.38	36 X 36	48 X 48	48 X 48
Single Lane Transition	W4-8	903.3.40	36 X 36	48 X 48	48 X 48
ROAD NARROWS	W5-1	903.3.15	36 X 36	48 X 48	48 X 48
NARROW BRIDGE	W5-2	903.3.16	36 X 36	48 X 48	48 X 48
ONE LANE BRIDGE	W5-3	903.3.17	36 X 36	48 X 48	-
Divided Highway	W6-1	903.3.18	36 X 36	48 X 48	-
Divided Highway Ends	W6-2	903.3.19	-	-	48 X 48
Two-Way Traffic	W6-3	903.3.42	36 X 36	48 X 48	-
Two-Way Traffic (2-Lane)	W6-5	903.3.55	36 X 36	48 X 48	-
Two-Way Traffic (3-Lane)	W6-5a	903.3.55	36 X 36	48 X 48
Passing Lane (plaque)	W6-6aP	903.3.55	42 X 12	-	-
Passing Lane Ends	W6-16	903.3.55	36 X 36	-	-
Watch for Left-Turning Traffic in Passing Lane	W6-17	903.3.55	72 X 48	-	-
Hill	W7-1	903.3.14	36 X 36	48 X 48	48 X 48
Uphill	W7-1c	903.3.14	36 X 36	48 X 48	48 X 48
Percent Grade	W7-3P	903.3.63	24 X 18	30 X 24	30 X 24
Next _ Miles (plaque)	W7-3aP	903.3.63	24 X 18	30 X 24	30 X 24
Bump	W8-1	903.3.23	36 X 36	48 X 48	48 X 48
Dip	W8-2	903.3.23	36 X 36	48 X 48	48 X 48
Pavement Ends	W8-3	903.3.24	36 X 36	-	-
Slippery When Wet	W8-5	903.3.25	36 X 36	48 X 48	48 X 48
Truck Crossing	W8-6	903.3.49	36 X 36	48 X 48	48 X 48
Fallen Rocks	W8-14	903.3.26	36 X 36	48 X 48	48 X 48
Road May Flood	W8-18	903.3.28	36 X 36	48 X 48	48 X 48
Impassable During High Water	W8-34	903.3.28	36 X 36	48 X 48	48 X 48
Left (Right) Lane Ends	W9-1	903.3.39	36 X 36	48 X 48	48 X 48
Lanes Merge	W9-4	903.3.40	36 X 36	48 X 48	48 X 48
Right (Left) Lane Exit Only	W9-7	903.3.41	132 X 70	-	132 X 70
Bicycle	W11-1	903.3.45	36 X 36	-	-
Pedestrian	W11-2	903.3.53	36 X 36	48 X 48	-
Cattle	W11-4	903.3.53	36 X 36	48 X 48
Farm Vehicle	W11-5	903.3.51	36 X 36	-	-
Equestrian	W11-7	903.3.53	36 X 36	-	-
Emergency Vehicle	W11-8	903.3.52	36 X 36	48 X 48	48 X 48
Truck Entrance	W11-10	903.3.50	36 X 36	48 X 48	48 X 48
Emergency Signal Ahead (plaque)	W11-12P	903.3.52	36 X 30	-	36 X 30
Horse-Drawn Vehicle	W11-14	903.3.48	36 X 36	48 X 48	48 X 48
Bike / Ped	W11-15	903.3.46	36 X 36	48 X 48	48 X 48
Trail Crossing	W11-15a	903.3.47	36 X 36	-	-
Double Arrow	W12-1	903.3.20	30 X 30	36 X 36	36 X 36
Low Clearance Advance	W12-2	903.3.22	36 X 36	48 X 48	48 X 48
Low Clearance (overhead)	W12-2a	903.3.22	84 X 24	-	84 X 24
Advisory Speed	W13-1P	903.3.33	24 X 24	30 X 30	30 X 30
Advisory Speed (plaque)	W13-1aP	903.3.33	48 X 15	-	48 X 15
Advisory Exit Speed	W13-2	903.3.12	-	-	48 X 60
Advisory Ramp Speed	W13-3	903.3.12	-	-	48 X 60
Advisory Exit Speed with 270° Loop Arrow	W13-6	903.3.12	-	-	48 X 84
Advisory Ramp Speed with 270° Loop Arrow	W13-7	903.3.12	-	-	48 X 84
Advisory Exit Speed with 180° Hairpin Arrow	W13-8	903.3.12	-	-	48 X 84
Advisory Ramp Speed with 180° Hairpin Arrow	W13-9	903.3.12	-	-	48 X 84
Advisory Exit Speed with 90° Turn Arrow	W13-10	903.3.12	-	-	48 X 72
Advisory Ramp Speed with 90° Turn Arrow	W13-11	903.3.12	-	-	48 X 72
Advisory Exit Speed with Truck Rollover	W13-12	903.3.12	-	-	48 X 84
Advisory Ramp Speed with Truck Rollover	W13-13	903.3.12	-	-	48 X 84
Vehicle Speed Feedback Sign	W13-20	903.3.13	30 X 36	-	48 X 60
Vehicle Speed Feedback (plaque)	W13-20aP	903.3.13	30 X 24	-	48 X 36
Dead End	W14-1	903.3.21	36 X 36	36 X 36	-
No Outlet	W14-2	903.3.21	36 X 36	36 X 36	-
No Passing Zone (pennant)	W14-3	903.3.43	-	-	-
Road Ends	W14-13	903.3.21	36 X 36	36 X 36	-
In Road (plaque)	W16-1P	903.3.66	24 X 18	-	24 X 18
XX FEET (plaque)	W16-2P	903.3.60	24 X 18	30 X 24	30 X 24
XX MILES (plaque)	W16-3P	903.3.60	24 X 18	30 X 24	30 X 24
NEXT _ FEET (plaque)	W16-4P	903.3.60	24 X 18	30 X 24	30 X 24
Directional Arrow (plaque)	W16-5P	903.3.61	30 X 21	-	30 X 21
Advance Turn Arrow (plaque)	W16-6P	903.3.61	30 X 21	-	30 X 21
Downward Diagonal Arrow (plaque)	W16-7P	903.3.62	30 X 21	-	30 X 21
Dual Downward Diagonal Arrow (plaque)	W16-7aP	903.3.62	30 X 21	-	30 X 21
Two Line Street Name (plaque)	W16-8aP	903.3.64	Varies X 15	Varies X 24	Varies X 24
Advance Street Name (plaque)	W16-8P	903.3.64	Varies X 8	Varies X 12	Varies X 12
Ahead (plaque)	W16-9P	903.3.44, 903.3.53	30 X 18	-	30 X 18
Notice (plaque)	W16-18P	903.3.68	36 X 12	48 X 18	48 X 18
Except to Turn (plaque)	W16-23P	903.3.68	48 X 30	-	-
Except to Exit (plaque)	W16-24P	903.3.68	48 X 30	-	-
Double Reverse Curve Left - 1 Lane	W24-1L	903.3.7	36 X 36	-	36 X 36
Double Reverse Curve Left - 2 Lanes	W24-1aL	903.3.7	36 X 36	-	36 X 36
Double Reverse Curve Left - 3 Lanes	W24-1bL	903.3.7	36 X 36	-	36 X 36
Oncoming Traffic Has Extended Green	W25-1	903.3.36	24 X 30	-	-
Oncoming Traffic May Have Extended Green	W25-2	903.3.36	24 X 30	-	-
Watch for Stopped Traffic	W26-1	903.3.31	36 X 36	48 X 48	48 X 48
Travel Safe Zone	W27-1	903.3.56	36 X 48	48 X 60	48 X 60

903.3.4 Placement of Warning Signs (MUTCD Section 2C.04)

Support. Information on the placement of warning signs is contained in EPG 903.1.13 through 903.1.18.

The time needed for detection, recognition, decision, and reaction is called the Perception-Response Time (PRT). Table 903.3.4 is provided as an aid for determining warning sign location. The distances shown in Table 903.3.4 can be adjusted for roadway features, other signing, and to improve visibility.

Guidance. Warning signs should be placed so that they provide an adequate PRT. The distances contained in Table 903.3.4 should be applied with engineering judgment.

Minimum spacing between warning signs with different messages should be based on the estimated PRT for driver comprehension of and reaction to the second sign.

The effectiveness of the placement of warning signs should be periodically evaluated. This is typically accomplished during routine sign inspection cycles. EPG 903.1.19 contains information regarding MoDOT’s sign maintenance program.

Standard. When any part of a warning sign assembly (post, sign, plaque, etc.) is replaced, maintained or modified, the placement of the sign shall be reviewed based on Table 903.3.4. Additionally, mounting height shall be reviewed for conformance with EPG 903.1.15.

**Table 903.3.4** Guidelines for Advance Placement of Warning Signs
Posted or 85th-Percentile Speed	Advance Placement Distance¹
	Condition A: Speed reduction and lane changing in heavy traffic²	Condition B: Deceleration to the listed advisory (mph) for the condition
		0³	10⁴	20⁴	30⁴	40⁴	50⁴	60⁴	70⁴
20 mph	225 ft	115 ft	N/A⁵	—	—	—	—	—	—
25 mph	325 ft	155 ft	N/A⁵	N/A⁵	—	—	—	—	—
30 mph	460 ft	200 ft	N/A⁵	N/A⁵	—	—	—	—	—
35 mph	565 ft	250 ft	N/A⁵	N/A⁵	N/A⁵	—	—	—	—
40 mph	670 ft	305 ft	100 ft⁶	100 ft⁶	N/A⁵	—	—	—	—
45 mph	775 ft	360 ft	125 ft	100 ft⁶	100 ft⁶	N/A⁵	—	—	—
50 mph	885 ft	425 ft	200 ft	175 ft	125 ft	100 ft⁶	—	—	—
55 mph	990 ft	495 ft	275 ft	225 ft	200 ft	125 ft	N/A⁵	—	—
60 mph	1100 ft	570 ft	350 ft	325 ft	275 ft	200 ft	100 ft⁶	—	—
65 mph	1200 ft	645 ft	450 ft	400 ft	350 ft	275 ft	200 ft	100 ft⁶	—
70 mph	1250 ft	730 ft	525 ft	500 ft	450 ft	375 ft	275 ft	150 ft	—
75 mph	1350 ft	820 ft	625 ft	600 ft	550 ft	475 ft	375 ft	250 ft	100 ft⁶

Note 1 — For Advanced Placement Distance — General The distances are adjusted for a sign legibility distance of 180 feet for Condition A. The distances for Condition B (with the exception of the potential stop condition) have been adjusted for a sign legibility distance of 250 feet, which is appropriate for an alignment warning symbol sign. For Conditions A and B, warning signs with less than 6-inch legend or more than four words, a minimum of 100 feet should be added to the advance placement distance to provide adequate legibility of the warning sign. Note 2 — For Condition A — Speed Reduction and Lane Change Conditions Typical conditions are locations where the road user must use extra time to adjust speed and change lanes in heavy traffic because of a complex driving situation or reduce to a new posted speed. Typical signs are Merge, Right Lane Ends, and Reduced Speed Ahead. The distances are determined by providing the driver a PRT of 14.0 to 14.5 seconds for vehicle maneuvers (2018 AASHTO Policy, Table 3-3, Decision Sight Distance, Avoidance Maneuver E) and adjusted for a legibility distance of 180 feet for the appropriate sign. Note 3 — For Condition B — Stop Condition Typical condition is the warning of a potential stop situation. Typical signs are Stop Ahead, Yield Ahead, Signal Ahead, and Intersection Warning signs. The distances are based on the 2018 AASHTO Policy, Table 3-1, Stopping Sight Distance, providing a PRT of 2.5 seconds, a deceleration rate of 11.2 feet/second². Note 4 — For Condition B — Reduced Speed Conditions Typical conditions are locations where the road user must decrease speed to maneuver through the warned condition. Typical signs are Turn, Curve, Reverse Turn, Reverse Curve, or Reduced Speed Ahead. The distance is determined by providing a 2.5 second PRT, a vehicle deceleration rate of 10 feet/second2, and adjusted for a sign legibility distance of 250 feet. Note 5 — For Condition B — N/A Values No suggested distances are provided for these speeds, as the placement location is dependent on site conditions and other signing. An alignment warning sign may be placed anywhere from the point of curvature up to 100 feet in advance of the curve. However, the alignment warning sign should be installed in advance of the curve and at least 100 feet from any other signs. Note 6 — For Condition B — for shortest distance values per posted speed The minimum advance placement distance is listed as 100 feet to provide adequate spacing between signs. General Note: Warning signs that advise road users about conditions that are not related to a specific location can be installed in an appropriate location, based on engineering judgment.

903.3.5 Horizontal Alignment Warning Signs – General (MUTCD Section 2C.05)

Support. A variety of horizontal alignment warning signs, pavement markings (see EPG 620.2), and delineation (see EPG 620.6) can be used to advise motorists of a change in the roadway alignment. Uniform application of these traffic control devices with respect to the amount of change in the roadway alignment conveys a consistent message establishing driver expectancy and promoting effective roadway operations. The design and application of horizontal alignment warning signs to meet those requirements are addressed in EPG 903.3.5 through 903.3.12.

The following list identifies treatments that might be used in advance of or within a change in horizontal alignment:

A. Horizontal alignment (Turn (W1-1), Curve (W1-2, W1-10 series, W1-11, W1-13, W1-15), Reverse Turn (W1-3), Reverse Curve (W1-4), Winding Road (W1-5), Exit Speed (W13-2), Ramp Speed (W13-3), and Combination Horizontal Alignment (Advisory Exit or Ramp Speed W13-6 through W13-11)) signs (see EPG 903.3.7, 903.3.9, and 903.3.12)

B. Advisory Speed (W13-1P) plaque (see EPG 903.3.59)

C. Chevron Alignment (W1-8) signs (see EPG 903.3.8)

D. One Direction Large Arrow (W1-6) sign (see EPG 903.3.10)

E. Sign or marking conspicuity enhancements (see EPG 903.1.11)

F. Longitudinal rumble strips (see EPG 620.10.1)

G. Vehicle Speed Feedback Sign (see EPG 903.3.13)

In addition, considerations other than traffic control devices, such as improved surface friction (high friction surface treatments), pavement edge treatments, lighting improvements, increased superelevation, and longitudinal rumble strips, might be used in advance of or within a change in horizontal alignment.

Guidance. Except as provided in EPG 903.3.6, the selection of traffic control devices used to warn road users of a change in horizontal alignment or to provide guidance in navigating the change in horizontal alignment should be based on consideration of one or more of the following factors:

A. The speed of traffic on the approach to the change in horizontal alignment

B. The recommended advisory speed for the change in horizontal alignment

C. The difference between the speed limit and the advisory speed, or the speed differential for the change in horizontal alignment

D. Daily traffic volumes on the roadway

E. The typical mix of vehicle types on the roadway

F. Sight distance throughout the change in horizontal alignment

G. Other types of traffic control devices that are used in advance of and within the change in horizontal alignment on the same roadway segment

H. The crash history of the change in horizontal alignment

I. The presence of driveways or intersections within the curve radius

903.3.6 Device Selection for Changes in Horizontal Alignment (MUTCD Section 2C.06)

Standard: Table 903.3.6 shall be used to specify the type(s) of warning signs to be used in advance of, and/or along, a horizontal curve, except as provided in following Option paragraph. The speed differential shall be the difference between the horizontal curve’s advisory speed and the roadway’s posted speed limit on the approach to the curve.

Option. A One Direction Large Arrow (W1-6) sign may be used to supplement Chevron Alignment (W1-8) signs when:

A. Site conditions limit the number of Chevron Alignment signs that are visible; or

B. The number of Chevron Alignment signs that can be installed within the change in horizontal alignment is less than the number determined by the spacing specified in EPG 903.3.8.

Additional or supplemental devices may be used for a change in horizontal alignment on the basis of engineering judgment.

If engineering judgment indicates the need for the horizontal alignment sign for a curve that can be driven at or above the posted speed limit, horizontal alignment signs may be installed with the Advisory Speed Plaque (W13-1P) displaying an advisory speed equal to the posted speed limit.

Warrants for center lines and edge lines are provided in EPG 620.2.2 and 620.2.11, respectively.

Provisions for delineators are contained in EPG 620.6.

Provisions for Advisory Speed (W13-1P) plaques are contained in EPG 903.3.59.

**Table 903.3.6** Application of Warning Signs for Changes in Horizontal Alignment
Speed Differential¹	Warning Signs Required
5 to 10 mph	Horizontal Alignment warning sign² Advisory Speed plaque³
15 mph or more	Horizontal Alignment warning sign² Advisory Speed plaque³ Chevron Alignment signs⁴
Speed differential shall be the difference between the horizontal curve’s advisory speed and the roadway’s posted speed limit. Provisions for the use of Horizontal Alignment warning signs are contained in EPG 903.3.6. Provision for Advisory Speed (W13-1P) plaques are contained in EPG 903.3.59. EPG 903.3.6 contains information about the use of a One Direction Large Arrow (W1-6) sign in place of or to supplement chevron alignment signs.

903.3.7 Horizontal Alignment Signs (W1-1 through W1-5, W1-11, W1-15, W24-1) (MUTCD Section 2C.07)

W1-1	W1-2	W1-3	W1-4
W1-5	W1-11	W1-15	W24-1L

Standard. When a horizontal alignment sign is required as provided in EPG 903.3.6 the sign installed in advance of the curve shall be a Curve (W1-2) sign unless a different sign is recommended or allowed by the provisions of this Article.

A Turn (W1-1) sign shall be used instead of a Curve (W1-2) sign in advance of a horizontal curve that has an advisory speed of 30 mph or less.

Guidance. Where there are two changes in roadway alignment in opposite directions that are separated by a tangent distance of less than 600 feet, the Reverse Turn (W1-3) sign should be used instead of multiple Turn (W1-1) signs or the Reverse Curve (W1-4) sign should be used instead of multiple Curve (W1-2) signs.

Support. Figures 903.3.7.1 and 903.3.7.2 provide examples of warning signs used for turns and curves.

Option. A Winding Road (W1-5) sign may be used instead of multiple Turn (W1-1) or Curve (W1-2) signs where there are three or more changes in roadway alignment each separated by a tangent distance of less than 600 feet.

A NEXT XX MILES (W7-3aP) supplemental distance plaque (see EPG 903.3.60) may be installed below the Winding Road sign where continuous roadway curves exist for a specific distance.

If the curve has a change in horizontal alignment of 135 degrees or more, the Hairpin Curve (W1-11) sign may be used instead of a Turn or Curve sign.

If the curve has a change of direction of approximately 270 degrees, such as on a cloverleaf interchange ramp, the 270-degree Loop (W1-15) sign may be used instead of a Turn or Curve sign.

Guidance. When the Hairpin Curve sign or the 270-degree Loop sign is installed, either a One-Direction Large Arrow (W1-6) sign or Chevron Alignment (W1-8) signs should be installed on the outside of the turn or curve.

Option. A double reverse left sign (W24-1L) and advisory speed plaque may be used on the crossroad approaches to a Diverging Diamond Interchange (DDI) when the difference between the speed limit and the advisory speed is 5 mph or greater. The need for this signing is based on engineering judgment if speeding through a DDI is a concern. An Advisory speed plaque is typically installed where the posted speed on the crossroad of the DDI is 40 mph or greater.

Standard. If used with an advisory speed plaque, the W24-1L sign shall display the number of double reverse arrows which indicates the number of lanes on the crossroad going through the DDI in the direction of travel where the sign is observed.

Support. See EPG 903.3.59 for information regarding Advisory Speed Plaques (W13-1P).

903.3.8 Chevron Alignment Sign (W1-8) (MUTCD Section 2C.08)

Support. Examples of when to use Chevron signs include locations where there is a crash history, evidence of drivers losing control on a curve or turn, a sharp change in horizontal alignment not readily visible to the driver, or as a systemic curve improvement program.

The majority of fatal and serious injury crashes are attributed to lane departure crashes (State Strategic Highway Safety Plan). Chevrons are a highly cost-effective way to reduce lane departure crashes in curves and turns.

Implementation of the 2009 MUTCD requirements for chevron deployments resulted in a statewide reduction in severe lane departure crashes in horizontal curves. To maintain this observed safety benefit, MoDOT has established standards based on the 2009 MUTCD criteria, which is above the minimum requirements in the 11th Edition of the MUTCD. For more details on the safety benefits of chevrons, contact the Highway Safety and Traffic Division.

Standard. The use of the Chevron Alignment (W1-8) sign (see Figure 903.3.7.2) to provide additional emphasis and guidance for a change in horizontal alignment shall be in accordance with the information provided in EPG 903.3.6.

The Chevron Alignment sign shall be a vertical rectangle. No border shall be used on the Chevron Alignment sign.

If used, Chevron Alignment signs shall be installed on the outside of a turn or curve, in line with and at approximately a right angle to approaching traffic. Chevron Alignment signs shall be installed at a minimum height of 4 feet, measured vertically from the bottom of the sign to the elevation of the near edge of the traveled way, which will locate the sign at approximately the driver’s eye height.

Guidance. The approximate spacing of Chevron Alignment signs on the turn or curve measured from the point of curvature (PC) should be as shown in Table 903.3.8.

In addition to the Chevron Alignment signs placed throughout the curve, there should be one sign in advance of the PC and one after the PT. These signs should be spaced the same as the Chevron Alignment signs in the curve.

Option. The values in Table 903.3.8 are typical and variances for driveways, public roads, and other signs may alter the spacing. Engineering judgment may also be used to modify the spacing as long as road users always have at least two Chevron Alignment signs in view until the change in alignment eliminates the need for the signs.

Based on engineering judgement, chevron alignment signs may be omitted within incorporated city limits.

Guidance. The Chevron Alignment signs should be visible for a sufficient distance to provide the road user with adequate time to react to the change in alignment.

The single-sided Chevron sign should only be used where only one direction of travel is impacted, such as on an expressway. The double-side Chevron (W1-8D) should be used on two-lane, two-way roads.

At the end of a four-lane divided highway, where the traffic reduces to two lanes, chevrons should be used to direct traffic from the dual lanes that are ending and being redirected to the two-lane roadway.

Option. Chevron Alignment signs may also be used on any other roadways based on engineering judgment.

Chevron Alignment signs may be used in addition to the One-Direction Large Arrow (W1-6) sign on turns posted at 30 mph or less.

Guidance. As chevrons are installed, all horizontal alignment signing (chevrons, curve and turn signing, advisory speed plaques and arrow boards) on a corridor should be evaluated to ensure the installations meet current standards. Aspects of existing horizontal alignment signs to look at should include spacing of existing chevrons, offset and mounting heights of any horizontal alignment sign as well as the distance advanced warning signs are installed from the curve/turn. The need for curve/turn signs should be reevaluated if the ball banking measurements from when the signs were installed are out of date due to roadway/pavement improvements or due to changes in vehicle performance.

Option. LEDs may be used to enhance the conspicuity of Chevron Alignment signs (see EPG 903.1.12).

Standard. The LEDs used in the Chevron Alignment sign shall consist of yellow LEDs outlining the chevron symbol.

Chevron Alignment signs shall not be placed on the far side of a T-intersection facing traffic on the stem approach to warn drivers that a through movement is not physically possible, as this is the function of a Two-Direction (or One-Direction) Large Arrow sign.

Chevron Alignment signs shall not be used to mark obstructions within or adjacent to the roadway, including the beginning of guardrails or barriers, as this is the function of an object marker (see EPG 903.3.70).

Chevron Alignment signs directing traffic to the right shall not be used in the central island of a roundabout or a neighborhood traffic circle.

**Table 903.3.8** Typical Spacing of Chevron Alignment Signs on Horizontal Curves
Advisory Speed	Curve Radius	Sign Spacing
15 mph or less	Less than 200 feet	40 feet
20 to 30 mph	200 to 400 feet	60 feet
35 to 45 mph	401 to 700 feet	80 feet
50 to 60 mph	701 to 1,250 feet	100 feet
more than 60 mph	More than 1,250 feet	140 feet
Note: The relationship between curve radius and the advisory speed shown in this table should not be used to determine the advisory speed.

903.3.9 Combination Horizontal Alignment/Intersection Signs (W1-10 Series) (MUTCD Section 2C.09)

W1-10	W1-10a	W1-10b
W1-10c	W1-10d	W1-10e

Option. The Turn (W1-1) sign, the Curve (W1-2) sign, and the Reverse Curve (W1-4) sign may be combined with the Cross Road (W2-1) sign or the Side Road (W2-2 or W2-3) sign to create a combination Horizontal Alignment/Intersection (W1-10 series) sign that depicts the condition where an intersection occurs within or immediately adjacent to a turn or curve.

Support. EPG 903.2.64 contains information about the use of an advance street name plaque to identify an intersecting road.

Guidance. Elements of the combination Horizontal Alignment/Intersection sign related to horizontal alignment should comply with the provisions of EPG 903.3.7, and elements related to intersection configuration should comply with the provisions of EPG 903.3.33. The symbol design should approximate the configuration of the intersecting roadway(s). No more than one Cross Road or two Side Road symbols should be displayed on any one combination Horizontal Alignment/Intersection sign.

A layout of the proposed sign should be included when ordering or when including the sign in design plans.

Standard. The use of the combination Horizontal Alignment/Intersection sign shall be in accordance with the provisions of EPG 903.3.7 for the appropriate Turn or Curve sign.

If used, a W1-10L sign designation shall indicate a curve to the left, while a W1-10R sign designation shall indicate a curve to the right.

903.3.10 One-Direction Large Arrow Sign (W1-6) (MUTCD Section 2C.10)

W1-6

Standard. A One-Direction Large Arrow sign shall be used to delineate a change in horizontal alignment where the advisory speed is 30 mph or lower.

The One-Direction Large Arrow sign shall be a horizontal rectangle with an arrow pointing to the left or right.

If used, the One-Direction Large Arrow sign shall be installed on the outside of a turn or curve in line with and at approximately a right angle to approaching traffic.

The One-Direction Large Arrow sign shall not be used where there is no alignment change in the direction of travel, such as at the beginnings and ends of medians or at center piers.

The One-Direction Large Arrow sign directing traffic to the right shall not be used in the central island of a roundabout.

Guidance. The One-Direction Large Arrow sign should be visible for a sufficient distance to provide the road user with adequate time to react to the change in alignment.

If Chevron Alignment signs are used to supplement the One-Direction Large Arrow sign, chevrons, and arrow signs should be installed so they do not visually block each other.

903.3.11 Truck Rollover Sign (W1-13) (MUTCD Section 2C.11)

Option. A Truck Rollover (W1-13) sign may be used as a supplement to a horizontal alignment warning sign to warn drivers of vehicles with a high center of gravity, such as trucks, tankers, and recreational vehicles, of a curve or turn where there are:

A. Past incidents of truck rollovers at the specific location,

B. High volumes of trucks, or

C. A speed differential (see EPG 903.3.6) that might pose a greater risk for vehicles with high centers of gravity.

Guidance. Where engineering judgment determines the need for the installation of a Truck Rollover (W1-13) sign, it should be located downstream of the horizontal alignment warning sign in advance of the curve.

Standard. If a Truck Rollover (W1-13) sign is used, it shall be accompanied by an Advisory Speed (W13-1P) plaque indicating the recommended speed for vehicles with a higher center of gravity.

Option. The Truck Rollover sign may include conspicuity enhancements, or may be a blank-out sign, activated by the detection of an approaching vehicle with a high center of gravity that is traveling in excess of the recommended speed for the condition.

Support. The curved arrow on the Truck Rollover sign shows the direction of roadway curvature. The truck tips in the opposite direction.

903.3.12 Advisory Exit and Ramp Speed Signs (W13-2 and W13-3) and Combination Horizontal Alignment/Advisory Exit and Ramp Speed Signs (W13-6 through W13-13) (MUTCD Section 2C.12)

Standard. Where an advisory speed is posted in advance of a freeway or expressway exit, the Advisory Exit Speed (W13-2) sign shall be used.

Where an advisory speed is posted in advance of a conventional road ramp or to another roadway or roadside facility, the Advisory Ramp Speed (W13-3) sign shall be used.

An Advisory Exit Speed or Advisory Ramp Speed sign shall be used when the difference between the mainline roadway speed limit and the exit or ramp advisory speed in the vicinity of the departure is 20 mph or greater.

Guidance. An Advisory Exit Speed or Advisory Ramp Speed sign should be used when the difference between the mainline roadway speed limit and the exit or ramp advisory speed in the vicinity of the departure is 15 mph.

Option. An Advisory Exit Speed or Advisory Ramp Speed sign may be used based on engineering judgment when the difference between the mainline roadway speed limit and the exit or ramp advisory speed in the vicinity of the departure is 10 mph or less.

The Combination Horizontal Alignment/Advisory Exit Speed (W13-6, W13-8, and W13-10) signs may be used in lieu of the Advisory Exit Speed (W13-2) sign, and the combination Horizontal Alignment/Advisory Ramp Speed (W13-7, W13-9, and W13-11) signs may be used in lieu of the Advisory Ramp Speed (W13-3) sign.

The Combination Truck Rollover/Advisory Exit Speed and Truck Rollover/Advisory Ramp Speed (W13-12 and W13-13) signs may be used in lieu of the W13-2 and W13-3 signs respectively if the tip over condition is in the vicinity of the gore.

Standard. Roadway geometrics represented on the Combination Horizontal Alignment/Advisory Exit and Combination Horizontal Alignment/Advisory Ramp Speed signs shall be limited to the standard signs shown in the EPG.

Guidance. If used, the Advisory Exit Speed sign or the Combination Horizontal Alignment/Advisory Exit Speed sign should be installed along the deceleration lane. The Advisory Exit Speed or the Combination Horizontal Alignment/Advisory Exit Speed signs should be visible in time for the road user to decelerate and make an exiting maneuver.

Regulatory Speed Limit signs (see EPG 903.3.20) should not be located in the vicinity of exit ramps or deceleration lanes, particularly where they will conflict with the advisory speed displayed on the Advisory Exit or Ramp Speed signs.

Support. EPG 903.3.6 contains provisions for the determination of the displayed advisory speed.

Table 903.3.4 lists recommended advance sign placement distances for deceleration to various advisory speeds.

Option. Where there is a need to remind road users of the recommended advisory speed, a horizontal alignment warning sign with an advisory speed plaque displaying the same advisory speed may be installed at a downstream location along the ramp.

Guidance. If the ramp curvature changes to the extent that it warrants a lower advisory speed, a horizontal alignment warning sign with the new advisory speed should be displayed in advance of the change in curvature.

Option. The One-Direction Large Arrow (W1-6) sign may be installed beyond the exit gore on the outside of the curve to provide additional warning of an immediate change in curvature. When used in conjunction with the exit speed, the One-Direction Large Arrow (W1-6) sign may be supplemented with a Confirmation Advisory Speed (W13-1aP) plaque when the plaque is not used with the Exit Gore (E5-1 series) sign.

Guidance. The horizontal alignment symbol displayed on the Combination Horizontal Alignment/Advisory Exit and Ramp Speed signs should be consistent with the horizontal geometry of the ramp.

Support. Examples of advisory speed signing for exit ramps are shown in Figure 903.3.12.

903.3.13 Vehicle Speed Feedback Sign and Plaque (W13-20 and W13-20aP) (MUTCD Section 2C.13)

Option. A Vehicle Speed Feedback (W13-20) sign or (W13-20aP) plaque (see Figure 903.3.13) that displays the speed of an approaching vehicle to the vehicle operator may be used to provide warning to drivers of their speed in relation to either a speed limit (R2-1) sign or a horizontal alignment warning sign assembly with a posted advisory speed.

Standard. When used to display the speed of an approaching vehicle in relation to the posted speed limit, the Vehicle Speed Feedback (W13-20aP) plaque shall be mounted below a Speed Limit (R2-1) sign (see EPG 903.2.20).

The Vehicle Speed Feedback assembly shall not be installed at a location where the posted speed limit on the route changes. Vehicle Speed Feedback assemblies shall be placed anywhere downstream of a speed limit change but shall be a minimum of 200 feet downstream of a speed limit change on conventional routes and a minimum of 400 feet downstream of a speed limit change on expressways of freeways. Vehicle Speed Feedback assemblies shall be installed in accordance with the Vehicle Speed Feedback Typical Application.

When used to supplement a horizontal alignment warning sign advisory speed, the Vehicle Speed Feedback (W13-20) sign shall be an independent installation near the point of curvature of a horizontal curve (see EPG 903.3.6).

The legend YOUR SPEED shall be a black legend on a yellow retroreflective background, except as provided in EPG 616.8.1 and 908.2.1. The changeable legend displaying the speed of the approaching vehicle shall be a yellow luminous legend on a black opaque background. The vehicle speed displayed on the changeable portion of the sign shall be displayed as an integer. The Vehicle Speed Feedback sign and plaque shall not flash, strobe, change color, or use other animated elements integrated into the changeable legend display. When no vehicles are approaching, the changeable display shall not display a legend.

Vehicle Speed Feedback sign equipment shall not have the capability to collect, store or transmit personally identifiable information of any type.

Guidance. The changeable portion of the Vehicle Speed Feedback legend should be approximately the same height, width, and stroke of those on the Speed Limit sign it supplements or is mounted below.

When a W13-20aP plaque is used with a Speed Limit sign it should be approximately the same width as the Speed Limit sign it is mounted below.

903.3.14 Hill Signs (W7-1 and W7-1c) (MUTCD Section 2C.14)

Guidance. The Hill (W7-1) sign should be used in advance of a downgrade where the length, percent of grade, horizontal curvature, and/or other physical features require special precautions on the part of road users.

The Hill sign and supplemental grade (W7-3P) plaque (see EPG 903.3.63) used in combination, or the W7-1a sign used alone, should be installed in advance of downgrades for the following conditions:

A. 5% grade that is more than 3,000 feet in length,

B. 6% grade that is more than 2,000 feet in length,

C. 7% grade that is more than 1,000 feet in length,

D. 8% grade that is more than 750 feet in length, or

E. 9% grade that is more than 500 feet in length.

These signs should also be installed for steeper grades or where crash experience and field observations indicate a need.

Supplemental plaques (see EPG 903.3.57 and 903.3.63) and larger signs should be used for emphasis or where special hill characteristics exist. On longer grades, the use of the Hill sign with a distance (W7-3aP) plaque at periodic intervals of approximately 1-mile spacing should be considered.

Support. The Uphill (W7-1c) sign is also available by special request.

903.3.15 ROAD NARROWS Sign (W5-1) (MUTCD 2C.17)

Guidance. A ROAD NARROWS (W5-1) sign should be used in advance of a transition on two-lane roads where the pavement width is reduced abruptly to a width such that vehicles traveling in opposite directions cannot simultaneously travel through the narrow portion of the roadway without reducing speed.

Option. Additional emphasis may be provided by the use of object markers and delineators (see EPG 903.3.70 through EPG 903.3.73 and EPG 620.6). The Advisory Speed (W13-1P) plaque (see EPG 903.3.59) may be used to indicate the recommended speed.

903.3.16 NARROW BRIDGE Sign (W5-2) (MUTCD Section 2C.18)

Guidance. A NARROW BRIDGE (W5-2) sign should be used in advance of any bridge or culvert having a two-way roadway horizontal clearance of 16 to 18 feet, or any bridge or culvert having a roadway horizontal clearance less than the width of the approach travel lanes.

Additional emphasis should be provided by the use of object markers, delineators, and/or pavement markings.

Option. A NARROW BRIDGE sign may be used in advance of a bridge or culvert on which the approach shoulders are narrowed or eliminated.

903.3.17 ONE LANE BRIDGE Sign (W5-3) (MUTCD Section 2C.19)

Guidance. A ONE LANE BRIDGE (W5-3) sign should be used on two-way roadways in advance of any bridge or culvert:

A. Having a roadway horizontal clearance of less than 16 feet, or

B. Having a roadway horizontal clearance of less than 18 feet when commercial vehicles constitute a high proportion of the traffic, or

C. Having a roadway horizontal clearance of 18 feet or less where the sight distance on the approach is less than that shown in Condition A of Table 903.3.4.

Additional emphasis should be provided by the use of object markers, delineators, and/or pavement markings.

Option. STOP (R1-1) or YIELD (R1-2) signs (see EPG 903.2.4 and 903.2.5) and related pavement markings (see EPG 620.2.20 and 620.2.21) may be used when conditions A, B, or C in the first Guidance paragraph of this Article apply.

903.3.18 Divided Highway Sign (W6-1) (MUTCD Section 2C.20)

Guidance. A Divided Highway (W6-1) sign should be used on the approaches to a section of highway (not an intersection or junction) where the opposing flows of traffic are separated by a median or other physical barrier.

Standard. The Divided Highway (W6-1) sign shall not be used instead of a Keep Right (R4-7 series) sign on the approach end of a median island.

903.3.19 Divided Highway Ends Sign (W6-2) (MUTCD Section 2C.21)

Guidance. A Divided Highway Ends (W6-2) sign should be used in advance of the end of a section of physically divided highway (not an intersection or junction) as a warning of two-way traffic ahead.

The Two-Way Traffic (W6-3) sign (see EPG 903.3.42) should be used to give warning and notice of the transition to a two-lane, two-way section.

903.3.20 Double Arrow Sign (W12-1) (MUTCD Section 2C.23)

Option. The Double Arrow (W12-1) sign may be used to advise road users that traffic is permitted to pass on either side of an island, obstruction, or gore in the roadway. Traffic separated by this sign may either rejoin or change directions.

Guidance. If used on an island, the Double Arrow sign should be mounted near the approach end (see EPG 903.3.13).

If used in front of a pier or obstruction, the Double Arrow sign should be mounted on the face of, or just in front of, the pier or obstruction. Where stripe markings are used on the pier or obstruction, they should be discontinued to leave a 3-inch space around the outside of the Double Arrow sign.

903.3.21 DEAD END, NO OUTLET, and ROAD ENDS Signs (W14-1, W14-2, and W14-13) (MUTCD Section 2C.24)

Option. DEAD END (W14-1) sign may be used at the entrance to a single road or street that terminates without intersecting another street. The NO OUTLET (W14-2) sign may be used at the entrance to a road or road network from which there is no other exit.

The ROAD ENDS (W14-13) sign may be used to warn of a roadway which has no outlet and which terminates in a dead end and may be used in place of the DEAD END or NO OUTLET sign where the use of the DEAD END and NO OUTLET signs would have a negative effect on traffic generators or public perceptions due to the negative connotation of the message.

Guidance. When the W14-1, W14-2, or W14-13 sign is used, the sign should be posted as near as practicable to the entry point or at a sufficient advance distance to permit the road user to avoid the dead end or no outlet condition by turning at the nearest intersecting street.

Standard. The W14-1, W14-2, or W8-26 sign shall not be used in place of the ROAD CLOSED (R11-2) sign for temporary conditions, such as high water, bridge out, etc.

Support. Information about the use of Type 4 object markers to mark the end of the road or street is contained in EPG 903.3.73.

903.3.22 Low Clearance Signs (W12-2, and W12-2a) (MUTCD Section 2C.25)

W12-2a

Support. MoDOT is responsible for installing and maintaining overhead low clearance signs mounted on all structures passing over MoDOT routes as well as installing and maintaining overhead low clearance signs mounted all MoDOT structures passing over non-MoDOT routes (this does not include MoDOT structures passing over rail lines). MoDOT has developed specific provisions for the use of Low Clearance signs.

Standard. Low Clearance signing shall be installed to display vertical clearances available under structures within specified limits of statutory maximum vehicle heights.

The clearance displayed on the Low Clearance (W12-2 and W12-2a) signs shall be 2 inches less than the measured clearance to account for possible packed snow and ice. For example, a measured vertical clearance of 15 ft. shall be posted as 14 ft. 10 in. All clearance measurements shall be rounded down to the nearest full inch. For example, a measured vertical clearance of 14 ft. 9 ½ in. would be rounded down to 14 ft. 9 in. and posted as 14 ft. 7 in.

The statutory maximum vehicle heights and vertical clearances are as follows:

A. Within Commercial Zones = 15 ft. statutory maximum vehicle height (16’ 0” maximum posting).

B. On Interstate and designated highway network routes and on all routes within 10 miles of Interstate and designated highway network routes = 14 ft. statutory maximum vehicle height (15’ 0” maximum posting).

C. On routes greater than 10 miles from Interstate and designated highway network routes = 13 ft. 6 in. statutory maximum vehicle height (15’ 0” maximum posting).

Support. For specific details on commercial zone limits and designated highway network routes, see Missouri Vehicle Route Map.

Standard. The MoDOT posting requirements for Low Clearance signs are as follows:

A. Case I – Two Signs Required: Where the measured vertical clearance is 15 ft. 2 in. or less, but more than 13 ft. 8 in., two signs shall be used. First, a Low Clearance Overhead (W12-2a) sign shall be installed on the structure, and second, a ground-mounted Low Clearance Advance (W12-2) sign shall be placed approximately 750 ft. in advance of the structure. When an interchange is involved, the ground-mounted Low Clearance (W12-2) sign shall be located approximately 750 ft. in advance of the off-ramp.

B. Case II – Three Signs Required: Where the measured vertical clearance is 13 ft. 8 in. or less, three signs shall be used. First, a Low Clearance Overhead (W12-2a) sign shall be installed on the structure, second, a ground-mounted Low Clearance Advance (W12-2) sign shall be placed approximately 750 ft. in advance of the structure, and third, an additional Low Clearance Advance (W12-2) sign with a Distance Ahead (W16-2P or W16-3P) plaque below the sign shall be placed at the nearest intersecting road or wide point in the road at which a vehicle can detour or turn around.

C. Case III – One Sign: Where the measured vertical clearance is 15 ft. 2 in. or less and where the bridge is state maintained but the road beneath is not, a Low Clearance Overhead (W12-2a) sign shall be installed on the structure, but the ground-mounted Low Clearance Advance (W12-2) sign shall not be installed by MoDOT. The Low Clearance Advance sign may be installed and maintained by the local jurisdiction.

D. Case IV – Commercial Zones: Vertical clearance signing shall be provided for structures within commercial zones (see Section 304.190 of the Revised Statutes of Missouri). Any structure with a measured vertical clearance of 16 ft. 2 in. or less within the commercial zone limits shall be posted. For measured vertical clearances greater than 15 ft. 2 in. and equal to or less than 16 ft. 2 in. within commercial zones a Low Clearance Overhead (W12-2a) sign shall be installed on the structure. The signing for measured vertical clearances of 15 ft. 2 in. or less within commercial zones shall be as described for Case I or Case II.

In the case of an arch structure or a structure which has a sloping span resulting in different vertical clearances per lane, one Low Clearance Overhead (W12-2a) sign shall be centered over each lane displaying the vertical clearance available for that lane. One sign per lane shall be applied if the difference in vertical clearance between adjacent lanes is 6 inches or greater or when the vertical clearance between the far-right lane and far-left lane is 12 inches or greater.

Guidance. Clearances should be evaluated periodically to verify the displayed clearances are accurate and to determine if additional low clearance signing is necessary, particularly when resurfacing operations have occurred, on routes onto which over-height vehicles are normally directed under the permit process, and structures that are susceptible to catastrophic failure when struck by over-height vehicles. The information should be updated in the TMS.

Where there is a need to warn of a low clearance on an intersecting road or off a freeway or expressway exit, a rectangular warning sign with an appropriate word legend should be used rather than a W12-2 sign.

Option. When only one Overhead Low Clearance (W12-2a) sign is required and mounting one sign centered over the roadway is not practical, two W12-2a signs may be installed with one sign installed to the right of the travel lanes and one sign installed to the left of the travel lanes.

Guidance. The clearance shown on the Low Clearance Advance (W12-2) sign should match the clearance on the W12-2a sign or, if there are multiple W12-2a signs, should match the lowest clearance.

903.3.23 BUMP and DIP Signs (W8-1 and W8-2) (MUTCD Section 2C.26)

Support. BUMP and DIP signs (W8-1, W8-2) are limited use signs, only being used for locations where the condition cannot be corrected, such as low water crossings or highway-rail grade crossings.

See EPG 913.2.14 for low ground clearance conditions at highway-rail grade crossings.

Guidance. BUMP (W8-1) and DIP (W8-2) signs should be used in advance of a sharp rise or depression in the profile of the road.

Option. These signs may be supplemented with an Advisory Speed plaque (see EPG 903.3.59).

Guidance. The DIP sign should not be used in advance of a short stretch of depressed alignment that might momentarily hide a vehicle.

A short stretch of depressed alignment that might momentarily hide a vehicle should be treated as a no-passing zone when center line striping is provided on a two-lane or three-lane road (see EPG 620.2.3).

Option. BUMP and DIP signs may be used as temporary traffic control signs (WO8-1, WO8-2) for locations where the condition is temporary and/or where the condition can be corrected in the future (See EPG 616.6.50).

903.3.24 PAVEMENT ENDS Sign (W8-3) (MUTCD Section 2C.28)

Guidance. A PAVEMENT ENDS (W8-3) sign should be used where a paved surface changes to either a gravel treated surface or an earth road surface.

Option. An Advisory Speed plaque (see EPG 903.3.59) may be used when the change in roadway condition requires a reduced speed.

903.3.25 Slippery When Wet Sign (W8-5) (Section 2C.30)

Guidance. The Slippery When Wet sign (W8-5) is a limited use sign that should not be installed for locations where the condition can be corrected. Existing Slippery When Wet (W8-5) signs should be left in place until the condition is corrected.

Option. The Slippery When Wet (W8-5) sign may be used to warn of unexpected slippery conditions.

Guidance. When used, Slippery When Wet signs should be placed in advance of the beginning of the affected section (see Table 903.3.4), and additional signs should be placed at appropriate intervals along the road where the condition exists.

Option. The Slippery When Wet sign may be used as a temporary traffic control sign (WO8-5) for locations where the condition is temporary and/or where the condition can be corrected in the future (See EPG 616.6.50).

903.3.26 FALLEN ROCKS Signs (W8-14)

Option. The FALLEN ROCKS (W8-14) sign may be used in advance of an area that is adjacent to a hillside, mountain, or cliff where rocks frequently fall onto the roadway.

Guidance. When used, FALLEN ROCKS signs should be placed in advance of the beginning of the affected section (see Table 903.3.4), and additional signs should be placed at appropriate intervals along the road where the condition exists.

Standard. The district shall perform an evaluation of the FALLEN ROCKS site to determine whether existing installations of the FALLEN ROCKS sign is still necessary. If it is determined that the sign is not necessary, the sign will not be replaced at the end of the service life.

903.3.27 Warning Signs and Plaque for Motorcyclists (W8-15, W8-15aP, and W8-16) (MUTCD Section 2C.31)

Support. MoDOT does not install permanent W8-15, W8-15aP, and W8-16 signs and plaques. For temporary applications, see EPG 616.16.

903.3.28 IMPASSABLE WHEN WATER OVER ROAD Sign (MUTCD Section 2C.34)

Support. When a road goes underwater, MoDOT requires the road to be closed to traffic regardless of the depth of water over the road. This closure is accomplished by following TA-8W. This TA displays two figures; the first figure applies to locations which do not flood on a frequent basis and uses standard work zone signs to close the road. The second figure applies to roads that frequently go under water and utilize permanently installed signs. These permanent signs provide critical guidance to motorists between the time the road begins to flood to the time maintenance crews can physically close the road.

MoDOT has discontinued the use of the LOW WATER CROSSING (W8-35) sign, low water crossings are designed for water to routinely flow over the roadway while traffic passes through the water. MoDOT no longer maintains low water crossings on State routes, and MoDOT’s direction is to close any road covered in any depth of water. MoDOT has discontinued the use of the WATER GAUGE (W8-19a). Water gauges are intended to indicate the depth of the water over a road to allow motorists to judge if it is safe to proceed, however, MoDOT no longer supports motorists driving through any depth of water and closes any road which is covered by water.

Standard. Any roadway location which goes underwater shall be closed to traffic as soon as possible. Any location, regardless of flooding frequency, shall be closed using the signing package in the first figure of TA-8W.

Guidance. Any roadway which historically floods one or more times per year should have the permanent signing package found in the second figure of TA-8W installed. This applies to locations where streams and rivers rise and flood the road surface, but not in urban areas where a road floods due to blocked or overwhelmed storm drains. This signing package, which includes the DO NOT ENTER WHEN WATER OVER ROAD (R5-22) sign, provides motorists with advanced information on how they need to react to the flooded road before maintenance crews can get to the location and physically close the roadway. The flip signs allow for an expedited closure with the work zone signs already in place, only needing to flip them from the warning sign message to the work zone message upon arriving at the location, as well as deploying the barricades and ROAD CLOSED (R11-2) sign.

Existing LOW WATER CROSSING (W8-35) signs should be removed at the earliest convenience; the presence of these signs may encourage motorists to enter a flooded road if they see the depth of water and incorrectly believe it is shallow enough to safely pass.

Option. The signing package in the second figure of TA-8W may be installed at any location that may flood less than one time per year to facilitate quicker road closures.

903.3.29 Advance Traffic Control Signs (W3-1, W3-2, W3-3, and W3-4) (MUTCD Section 2C.35)

Standard. The Stop Ahead (W3-1), Yield Ahead (W3-2), and Signal Ahead (W3-3) Advance Traffic Control signs shall be installed on an approach to a primary traffic control device that is not visible for a sufficient distance to permit the road user to respond to the device (see Table 903.3.4). The visibility criteria for a traffic control signal shall be based on having a continuous view of at least two signal faces for the distance specified in Table 902.4.6.

Guidance. Where intermittent obstructions occur, engineering judgment should determine the treatment to be implemented.

The minimum visibility distance of a signal for a facility with a speed limit above 60 mph should be determined by summing the stopping sight distance (see Table 903.3.1) and the assumed queue length. The assumed queue length should be determined by engineering judgment.

If an advance traffic control sign is warranted for an approach at an intersection of a MoDOT maintained road and non-MoDOT maintained road, the agency responsible for the maintenance of the non-MoDOT road should be notified of the condition.

Support. Permanent obstructions causing the limited visibility might include roadway alignment or structures. Intermittent obstructions might include foliage or parked vehicles.

Option. An Advance Traffic Control sign may be used for additional emphasis of the primary traffic control device, even when the visibility distance to the device is satisfactory.

Signal Ahead (W3-3) signs may be posted on the right- and left-hand sides of the road on a high speed divided approach.

Support. EPG 903.3.64 contains information about the use of an advance street name plaque to identify an intersecting road.

Option. A BE PREPARED TO STOP (W3-4) sign may be used to warn of stopped traffic caused by a traffic control signal in advance of a section of roadway that regularly experiences traffic congestion, history of crashes, or based on engineering judgement.

A Warning Beacon (see EPG 902.18.3) may be used with an Advance Traffic Control or BE PREPARED TO STOP (W3-4) sign. If a warning beacon is used, the beacon(s) may be activated before the start of the yellow change interval referred to as lead flash, which is the time before the onset of yellow at which the warning beacon(s) begin to flash. Recommended values for lead flash in accordance with the posted speed limit are specified in Table 903.3.29.

**Table 903.3.29** Design Parameters for Advance Warning System
Posted Speed (mph)	Distance Between Warning Sign and Stop Line (ft)	Lead Flash, Advance Warning Before End of Green (sec)
70	871 to 975 max**	8
70	730 min* to 870	7
65	811 to 905 max**	8
65	645 min* to 810	7
60	661 to 745 max**	7
60	570 min* to 660	6
55	606 to 685 max**	7
55	495 min* to 605	6
50	476 to 550 max**	6
50	425 min* to 475	5
45	426 to 495 max**	6
45	360 min* to 425	5
The advance traffic control sign shall not be installed less than this minimum distance. *The sign placement distance can exceed the "max" distance. The lead flash time should be determined by coordinating with the MoDOT Highway Safety and Traffic Division.

Standard. When a BE PREPARED TO STOP (W3-4) sign is used in advance of a traffic control signal, it shall be used in addition to a Signal Ahead sign and shall be placed a minimum of 200 feet downstream from the Signal Ahead sign. The BE PREPARED TO STOP (W3-4) sign shall be installed as specified in Table 903.3.4 (See Figure 903.3.29.1).

A BE PREPARED TO STOP (W3-4) sign with a warning beacon shall not be considered for intersection approaches with a posted speed limit of 40 mph or less.

903.3.30 Advance Ramp Control Signal Signs (W3-7 and W3-8) (MUTCD Section 2C.37)

Option. A RAMP METER AHEAD (W3-7) sign may be used to warn road users that a freeway entrance ramp is metered and that they will encounter a ramp control signal (see EPG 902.16).

Guidance. When the ramp control signals are operated only during certain periods of the day, a RAMP METERED WHEN FLASHING (W3-8) sign should be installed in advance of the ramp control signal near the entrance to the ramp, or on the arterial on the approach to the ramp, to alert road users to the presence and operation of ramp meters.

Standard. The RAMP METERED WHEN FLASHING sign shall be supplemented with a Warning Beacon (see EPG 902.18.3) that flashes when the ramp control signal is in operation.

903.3.31 WATCH FOR STOPPED TRAFFIC Sign (W26-1) (MUTCD Section 2C.39)

Option. The WATCH FOR STOPPED TRAFFIC (W26-1) sign may be used to warn road users of the possibility of vehicles stopping abruptly in the travel lane due to recurring congested conditions.

903.3.32 Reduced Speed Limit Ahead and Speed Zone Signs (W3-5) (MUTCD Section 2C.40)

Standard. A Reduced Speed Limit Ahead (W3-5) sign shall be used to inform road users of a reduced speed zone where the speed limit is being reduced by more than 10 mph.

Option. A Reduced Speed Limit Ahead (W3-5) sign may be used to inform road users of a reduced speed zone where the speed limit is being reduced by 10 mph or less based if engineering judgment indicates the need for advance notice to comply with the posted speed limit ahead.

Standard. If used, a Reduced Speed Limit Ahead sign shall be followed by a Speed Limit (R2-1) sign (see EPG 903.2.20), installed at the beginning of the zone where the speed limit applies.

The speed limit displayed on the W3-5 sign shall be identical to the speed limit displayed on the subsequent Speed Limit sign.

903.3.33 Intersection Warning Signs (W2-1 through W2-8) (MUTCD Section 2C.41)

W2-4	W2-5	W2-6
W2-7L	W2-7R	W2-8

Support. Intersection Warning Signs are used when there is limited stopping sight distance, history of crashes, or based on engineering judgment.

Option. A Cross Road (W2-1), Side Road (W2-2, W2-3, or W2-3a), T-Intersection (W2-4), or Y-Intersection (W2-5) sign may be used in advance of an intersection to indicate the presence of an intersection and the possibility of turning or entering traffic.

Standard. The Circular Intersection (W2-6) sign shall be installed in advance of roundabout intersections. The appropriate Advisory Speed supplemental plaque (W13-1P) shall be installed below the Circular Intersection sign.

Option. If other circular intersections exist, that would not be classified as roundabouts, the Circular Intersection (W2-6) sign may be used.

Support. EPG 903.2.64 contains information about the use of an advance street name plaque to identify an intersecting road.

Guidance. The Intersection Warning sign should illustrate and depict the general configuration of the intersecting roadway, such as a cross road, side road, T-intersection, or Y-intersection.

Intersection Warning signs, other than the Circular Intersection (W2-6) sign, the T-intersection (W2-4) sign, and the Grade Crossing and Intersection Advance Warning (W10-2, W10-3, and W10-4) signs (see EPG 913.2.6) should not be used on approaches controlled by STOP signs, YIELD signs, or signals.

If an Intersection Warning sign is used where the side roads are not opposite of each other, the Offset Side Roads (W2-7) sign should be used instead of the Cross Road sign.

If an Intersection Warning sign is used where two closely-spaced side roads are on the same side of the highway, the Double Side Roads (W2-8) sign should be used instead of the Side Road sign.

No more than two side roads should be depicted on the same side of the highway on a W2-7 or W2-8 sign, and no more than three side roads should be depicted on a W2-7 or W2-8 sign.

903.3.34 Advance Intersection Signs (W2-10a and W2-11a)

Support. Advance Intersection signs are typically associated with restricted sight distance and gap selection at stop controlled intersections.

Option. The WATCH FOR ENTERING TRAFFIC (W2-10a) sign may be used on the uncontrolled through roadway approach to a side or cross road stop controlled intersection to warn of entering traffic from the side or cross road.

The WATCH FOR APPROACHING TRAFFIC (W2-11a) sign may be used on the side road stop controlled approach to warn of traffic approaching on the uncontrolled through road.

903.3.35 Two-Direction Large Arrow Sign (W1-7) (MUTCD Section 2C.43)

W1-7

Standard. The Two-Direction Large Arrow (W1-7) sign shall be a horizontal rectangle.

If used, the Two-Direction Large arrow sign shall be installed on the far side of a T-intersection in line with, and at approximately a right angle to, traffic approaching from the stem of the T-intersection.

The Two-Direction Large Arrow sign shall not be used where there is no change in the direction of travel such as at the beginnings and ends of medians or at center piers.

Guidance. The Two-Direction Large Arrow sign should be visible for a sufficient distance to provide the road user with adequate time to react to the intersection configuration.

903.3.36 Traffic Signal Oncoming Extended Green Signs (W25-1 and W25-2) (MUTCD Section 2C.44)

Standard. At locations where either a W25-1 or a W25-2 sign is required based on the provisions in EPG 902.6.1, the W25-1 or W25-2 sign shall be installed near the left-most signal face for the approach.

903.3.37 Merge Signs and Plaque (W4-1 and W4-5) (MUTCD Section 2C.45)

Guidance. The Merge (W4-1) sign should be installed on the side of the major roadway where merging traffic will be encountered and in such a position as to not obstruct the road user’s view of entering traffic.

When a Merge sign is installed on a major roadway, the symbol should be oriented right or left as appropriate to depict the side from which the merge occurs, with the arrow representing the major roadway and the curved stem representing the entering roadway.

When a Merge sign is to be installed on an entering roadway that curves before merging with the major roadway, such as a ramp with a curving horizontal alignment as it approaches the major roadway, the Entering Roadway Merge (W4-5) sign should be used to better portray the actual geometric conditions to road users on the entering roadway.

Where two roadways of approximately equal importance converge and merging movements are required, a Merge sign should be placed on each roadway.

The Merge sign should not be used where two roadways converge and merging movements are not required.

Standard. The Merge sign shall not be used in place of a Lane Ends (W4-2) sign (see EPG 903.3.39) where lanes of traffic moving on a single roadway must merge because of a reduction in the actual or usable pavement width.

Support. Examples of the use of Merge (W4-1) signs are shown in Drawing A in Figure 903.3.37.

903.3.38 Added Lane Signs (W4-3 and W4-6) (MUTCD Section 2C.46)

Guidance. The Added Lane (W4-3) sign should be installed in advance of a point where two roadways converge and merging movements are not required. When possible, the Added Lane sign should be placed such that it is visible from both roadways; if this is not possible, an Added Lane sign should be placed on the side of each roadway.

When an Added Lane (W4-3) sign is installed on a major roadway, the symbol should be oriented right or left as appropriate to depict the side from which the entering roadway converges, with the straight arrow representing the major roadway and the curved arrow representing the entering roadway. The sign should be located on the side of the major roadway from which the entering roadway converges.

When an Added Lane sign is to be installed on a roadway that curves before converging with another roadway that has a tangent alignment at the point of convergence, the Entering Roadway Added Lane (W4-6) sign should be used to better portray the actual geometric conditions to road users on the curving roadway.

Support. Examples of the use of Added Lane (W4-3) and Entering Roadway Added Lane (W4-6) signs are shown in Drawing B in Figure 903.3.37.

903.3.39 Lane Ends Signs (W4-2 and W9-1) (Section 2C.47)

Support. The Lane Ends (W4-2) and RIGHT (LEFT) LANE ENDS (W9-1) signs are used to warn of the reduction in the number of traffic lanes in the direction of travel.

The sequence of the W4-2 and W9-1 signs is illustrated in Figures 903.3.39.1 to 903.3.39.5

Guidance. The Lane Ends (W4-2) sign should be installed at the advance placement distance in accordance with Table 903.3.4.

A RIGHT (LEFT) LANE ENDS (W9-1) sign should be installed in advance of the Lane Ends sign, at the advance placement distance in accordance with Table 903.3.4, to provide additional warning that a lane is ending and that a merging maneuver will be required.

If a W9-1 sign is installed, a Distance (W16-2P series or W16-3P series) plaque (see EPG 903.3.59) should be installed below the W9-1 sign.

On one-way streets or on divided highways where the left-hand lane is ending and the width of the median will permit, the W9-1 and W4-2 signs should be placed facing approaching traffic on the left-hand side or median.

Option. Where a lane ends a distance beyond the intersection that is less than the advance placement distance indicated in Table 903.3.4, the W4-2 sign may be located at the far side of the intersection (see Figure 903.3.39.4).

Guidance. When the W4-2 sign is located at the far side of the intersection in accordance with the Option paragraph above, the W9-1 sign should be placed upstream of the intersection with the appropriate distance plaque.

Support. EPG 620.2.14 contains information regarding the use of pavement markings in conjunction with a lane reduction.

Guidance. Lane Ends signs should not be installed in advance of the downstream end of an acceleration lane.

Standard. The W4-2 and W9-1 signs shall not be used in dropped lane situations. In dropped lane situations on conventional roads at intersections, regulatory signs (see EPG 903.2.26) shall be used to inform road users that a through lane becomes a mandatory turn lane.

903.3.40 Lanes Merge Signs (W9-4 and W4-8) (MUTCD Section 2C.48)

Support. The LANES MERGE (W9-4) and Single-Lane Transition (W4-8) signs are used to warn of a merge of two lanes to one in the same direction of travel with a merging maneuver required for each lane (see Figure 903.3.39.5). This type of merge is for a geometric condition where both approach lanes merge into a single lane, not where one lane merges into the other. EPG 618.8.8 contains information about the use of the late merge sign.

Guidance. The Single-Lane Transition (W4-8) sign should be located at the advance placement distance in accordance with Table 903.3.4.

The Lanes Merge (W9-4) sign should be used in advance of the W4-8 sign to provide additional warning that both lanes form a single lane and that a merging maneuver is needed for the traffic in each lane.

903.3.41 RIGHT (LEFT) LANE EXIT ONLY Sign (W9-7) (MUTCD Section 2C.50)

Option. The RIGHT (LEFT) LANE EXIT ONLY (W9-7) sign may be used to provide advance warning to road users that traffic in the right-hand (left-hand) lane of a roadway will be required to depart the roadway at the next exit.

Guidance. If used, the W9-7 sign should be installed upstream from the first overhead guide sign that contains an EXIT ONLY sign panel or upstream from the first RIGHT (LEFT) LANE MUST EXIT (R3-33) regulatory sign, if used, whichever is farther upstream from the exit.

903.3.42 Two-Way Traffic Sign (W6-3) (MUTCD Section 2C.51)

Guidance. A Two-Way Traffic (W6-3) sign should be used to warn road users of a transition from a multi-lane divided section of roadway to a two-lane, two-way section of roadway.

A Two-Way Traffic (W6-3) sign with an AHEAD (W16-9P) plaque (see EPG 903.3.57) should be used to warn road users of a transition from a one-way street to a two-lane, two-way section of roadway.

Option. The Two-Way Traffic sign may be used to supplement the Divided Highway (Road) Ends (W6-2) sign discussed in EPG 903.3.19.

903.3.43 NO PASSING ZONE Sign (W14-3) (MUTCD Section 2C.53)

Support. The NO PASSING ZONE (W14-3) sign is not to be used on a system-wide basis. It is intended for special use as a measure to reduce crashes at locations where there is a history of crashes related to passing maneuvers.

Standard. The NO PASSING ZONE (W14-3) sign shall be a pennant-shaped isosceles triangle with its longer axis horizontal and pointing to the right. When used, the NO PASSING ZONE sign shall be installed on the left-hand side of the roadway at the beginning of no-passing zones identified by pavement markings or DO NOT PASS signs or both (see EPG 903.2.31 and 620.2.3).

The use of the NO PASSING ZONE sign shall be approved by the State Highway Safety and Traffic Engineer.

903.3.44 Vehicular Traffic Warning Signs (MUTCD Section 2C.54)

Option. Vehicular Traffic Warning signs may be used to alert road users to locations where unexpected entries into the roadway by trucks, bicycles, farm vehicles, emergency vehicles, golf carts, horse-drawn vehicles, or other vehicles might occur.

Guidance. Vehicular Traffic Warning signs should be used only at locations where the road user’s sight distance is restricted, or the condition, activity, or entering traffic would be unexpected.

If the condition or activity is seasonal or temporary, the Vehicular Traffic Warning sign should be removed or covered when the condition or activity does not exist.

Before advanced warning signs are installed, all efforts to correct the sight distance issues should be made as this will be far more effective to improve safety compared to installing a sign. Roadway alignments cannot be corrected easily, but removal of vegetation on and off the state right of way that blocks sight distance can address sight distance issues.

Option. Supplemental plaques (see EPG 903.3.57) with legends such as AHEAD, XX FEET, NEXT XX MILES, IN STREET, or IN ROAD may be mounted below Vehicular Traffic Warning signs to provide advance notice to road users of unexpected entries.

Standard. A Vehicular Traffic Warning sign assembly shall not be installed on an approach controlled by a STOP or a YIELD sign, except as provided in the following two Option paragraphs.

Option. The Vehicular Traffic Warning sign assembly may be installed on an approach to a circular intersection controlled by a YIELD sign where the crosswalk is at least 20 feet in advance of the yield point at the entrance to the circulatory roadway.

At a signalized or stop-controlled intersection the Vehicular Traffic Warning sign assembly may be installed on an approach to a channelized right-turn lane controlled by a YIELD sign where the crosswalk is at least 20 feet in advance of the yield point.

A Warning Beacon (see EPG 902.18.3) may be used with any Vehicular Traffic Warning sign to indicate specific periods when the condition or activity is present or is likely to be present, or to provide enhanced sign conspicuity.

903.3.45 Bicycle Warning (W11-1) Sign

Guidance. Bicycle Warning (W11-1) signs should be used only at locations where the road user’s sight distance is restricted, and the condition, activity, or entering traffic would be unexpected.

Option. Bicycle Warning (W11-1) signs may be used to alert road users to locations where unexpected entries into the roadway by cyclists might occur.

Support. Bicycle warning (W11-1) signs with a diagonal downward-pointing arrow (W16-7P) plaques are used to alert road users of locations where bicyclists routinely cross state highways.

Standard. If a post-mounted W11-1 sign is placed at the location of a bicycle crossing, a diagonal downward pointing arrow (W16-7P) plaque shall be mounted below the sign. The bicycle crossing warning sign with diagonal arrow supplemental plaque should be placed immediately in advance of, as near as possible, the crossing in both directions of travel. If the W11-1 sign is mounted overhead, the W16-7P supplemental plaque shall not be used.

Guidance. Bicycle crossing warning signs should be installed at locations where an established independent bicycle path crosses a state route. Bicycle crossing warning signs should not be installed where an established “US Bike Route” crosses a state route or where cyclists riding on the public roadways cross a state route.

Option. A Bicycle Warning (W11-1) sign with an AHEAD (W16-9P) supplemental plaque may be added in advance of the bicycle crossing if engineering judgement determines a need based on limited sight distance of the crossing.

Bicycle Warning (W11-1) signs with an In Road (W16-1P) plaque may be used to alert road users to locations where cyclists riding on the roadway might occur.

Standard. When bicycle warnings signs are installed to warn motorists of bicycle activity along a state highway, the IN ROAD (W16-1P) plaque shall be installed below the Bicycle Warning (W11-1) sign and shall match the color of the warning sign.

Support. Bicycle warning signs with the IN ROAD supplemental plaques (IN ROAD plaque replaces the SHARE THE ROAD plaque) are used to alert road users where bicyclists routinely ride along specific sections of state highways, in the travel lane or on the shoulder of the roadway.

Guidance. The use of Bicycle warning signs to warn road users of cyclist activity along specific sections of roadway should be based on identifiable, routine and/or frequent cyclist activity. Indications bicycle warnings signs should be installed should be based on conditions, such as, but not limited to:

A. Requests received by bicycle groups, or clubs, who indicate the state highways which are part of their group’s frequent cycling routes.

B. Requests from Amish, Mennonite or other communities who utilize bicycles as one of their primary modes of routine transportation, indicating the state highways which service their community’s cycling needs.

C. Sections of a state route where an established bicycle trail overlaps the state route for some length, using the roadway and not a dedicated bike lane, before returning to the independent trail again.

D. Cycling activity occurs a minimum of 3 days per week, 6 months per year.

Bicycle warning signs should not be installed along routes for the following conditions:

A. For the purpose of promoting cycling or conveying a bicycle friendly organization when there is no routine cycling activity on that route,

B. When cyclists have access to a dedicated bicycle lane along the route,

C. Where cyclists have access to a parallel bike facility, or multi-use path, or

D. In response to a request from an individual without verifying the need as described in this article.

Bicycle warning signs used to notify drivers of bicycle traffic on the state route should only be ground-mounted installations. Signs should be installed at the point on the route the activity begins and downstream of major public road entry points onto the state route.

Option. Additional bicycle warning signs may be installed based on engineering judgement if the distance between major road intersections is excessive or if there are areas with limited sight distance which may obscure bicycle traffic.

A NEXT XX MILES (W7-3aP) plaque (See EPG 903.3.60) may be installed below the IN ROAD plaque if engineering judgement determines the need to notify road users of the length of roadway over which unexpected cyclists riding along the road may occur.

903.3.46 Combined Bicycle/Pedestrian Crossing (W11-15) Sign

Option. Combined Bicycle/Pedestrian Crossing (W11-15) signs may be used to alert road users to locations where unexpected entries into the roadway by cyclists and pedestrians might occur.

Guidance. Combined Bicycle/Pedestrian warning signs should be installed at locations where an established shared use path crosses a state route.

Support. The combined Bicycle/Pedestrian (W11-15) sign is used where both bicyclists and pedestrians might be crossing the roadway at intersections with a shared-use path and state routes. A shared-use path is defined as a paved or gravel path, 8-10 foot wide, dedicated to bike and pedestrian traffic which is an independent facility from the roadway.

Standard. If a post-mounted W11-15 sign is placed at the location of the combined Bicycle/Pedestrian crossing, a diagonal downward pointing arrow (W16-7P) plaque shall be mounted below the sign. The Bicycle/Pedestrian warning sign with diagonal downward pointing arrow plaque shall be placed immediately in advance of, as near as possible, the crossing in both directions of travel. If the W11-15 sign is mounted overhead, the W16-7P supplemental plaque shall not be used.

Option. An advanced Bicycle/Pedestrian warning sign with an AHEAD (W16-9P) supplemental plaque may be added in advance of the Bicycle/Pedestrian crossing if engineering judgement determines a need based on limited sight distance of the crossing.

903.3.47 Trail Crossing (W11-15a) Sign

Option. TRAIL CROSSING (W11-15a) signs may be used to alert road users to locations where unexpected entries into the roadway by cyclists, pedestrians or equestrian activity might occur.

Support. The TRAIL CROSSING sign is used to warn of a rustic trail where pedestrian, bicyclist, or equestrian activities, might be crossing the state highway. A rustic trail would typically be an unpaved trail of an undefined width, but one that is visible and identifiable by a motorist as it crosses the right of way.

Guidance. TRAIL CROSSING signs should be installed at locations where an established rustic trail used by pedestrians, bicyclists, and equestrian activities crosses a state route.

Standard. If a post-mounted W11-15a sign is placed at the location of the rustic trail crossing, a diagonal downward pointing arrow (W16-7P) plaque shall be mounted below the sign. The W11-15a sign with diagonal downward pointing arrow plaque shall be placed immediately in advance of, as near as possible, the crossing in both directions of travel. If the W11-15a sign is mounted overhead, the W16-7P supplemental plaque shall not be used.

Option. A TRAIL CROSSING warning sign with an AHEAD (W16-9P) supplemental plaque may be added in advance of the trail crossing if engineering judgement determines a need based on limited sight distance of the crossing.

903.3.48 Horse-Drawn Vehicle (W11-14) Sign

Option. Horse-Drawn Vehicle (W11-14) signs may be used to alert road users to locations where unexpected horse-drawn vehicles are traveling along the roadway might occur.

Guidance. W11-14 signs should be used only at locations where the road user’s sight distance is restricted, and the condition, activity, or entering traffic would be unexpected.

Support. Horse-Drawn Vehicle warning signs with the IN ROAD (W16-1P) supplemental plaque (IN ROAD plaque replaces the SHARE THE ROAD plaque) are used to alert road users where horse-drawn vehicle traffic is routinely traveling along specific sections of state highways, in the travel lane or on the shoulder of the roadway.

Standard. When Horse-drawn vehicle warnings signs are installed to warn motorists of Horse-drawn vehicle activity along a state highway, the IN ROAD (W16-1P) plaque shall be installed below the Horse-drawn vehicle warning sign and shall match the color of the warning sign.

Guidance. The use of Horse-Drawn Vehicle signs to warn road users of horse-drawn vehicle activity along specific section of roadway should be based on identifiable, routine and/or frequent horse-drawn vehicle activity. The application of horse-drawn vehicle warning signs is limited to the Amish, Mennonite or other communities who utilize horse-drawn vehicles as one of their primary modes of routine transportation. The district should work with community leadership to determine the state routes their communities utilize on a routine basis to determine the most appropriate sign installation locations.

Horse-Drawn Vehicle signs used to notify drivers of horse-drawn vehicle traffic on the state route should only be ground-mounted installations. Signs should be installed at the point on the route the activity begins and downstream of each major public road entry points onto the state route.

Option. Additional Horse-Drawn Vehicle signs with IN ROAD plaques may be installed based on engineering judgement if the distance between major road intersections is excessive or if there are areas with limited sight distance which may obscure horse-drawn vehicle traffic.

A NEXT XX MILES (W7-3aP) plaque may be added below the IN ROAD plaque if engineering judgement determines the need to notify drivers of the length of roadway affected by the warning sign.

903.3.49 TRUCK CROSSING (W8-6) Sign

Option. Truck Crossing (W8-6) signs may be used to alert road users to locations where unexpected entries into the roadway by trucks crossing the road might occur.

Guidance. W8-6 signs should be used only at locations where the road user’s sight distance is restricted, and the condition, activity, or entering traffic would be unexpected.

Support. The W8-6 sign is used to alert road users to locations where trucks are routinely crossing a state highway at a commercial entrance intersection. A typical example would be a company with facilities on either side of a highway where raw materials, finished goods, etc. are routinely moved sites. In these cases, warning signs with fluorescent yellow backgrounds are installed in a permanent installation.

Option. For cases involving temporary truck crossings, such as haul roads moving earth or quarry materials, a TR12 Truck crossing agreement (see EPG 153.21) may be used to install a temporary traffic control sign with a fluorescent orange background.

Guidance. W8-6 signs should be installed at locations where there is consistent and routine truck traffic crossing a state route where the road user’s sight distance is restricted, and the crossing would be unexpected based on engineering judgement.

The truck crossing for which the warning sign is being installed should be recognizable by the presence of a on premise business marquee sign, business name on structures or other indicators to allow drivers to associate the warning sign to the entrance/site where tucks could be crossing the state highway.

Standard. If used, the TRUCK CROSSING sign shall be placed in accordance with Table 903.3.4.

The TRUCK CROSSING sign shall only be installed for the direction of travel where the road user’s sight distance is restricted.

The TRUCK CROSSING sign shall not be used on state highways at intersections with city streets or county roads, to address issues at these types of intersections other warning signs, such as Intersection Warning signs are more appropriate.

903.3.50 Truck Entrance (W11-10) Sign

Option. Truck Entrance (W11-10) signs may be used to alert road users to locations where unexpected entries into the roadway by trucks might occur.

Guidance. Truck Entrance signs should be used only at locations where the road user’s sight distance is restricted, and the condition, activity, or entering traffic would be unexpected.

Support. The W11-10 sign is used to alert road users to locations where trucks are routinely entering and leaving a state highway at a non-public roadway intersection, commercial entrance. A typical example would be trucks entering and exiting a quarry entrance which has direct access to the state route. In these cases, warning signs with fluorescent yellow backgrounds are installed in a permanent installation.

Option. For cases involving a temporary truck entrance, such as logging trucks entering and leaving a timber harvest location, a TR12 Truck crossing agreement (see EPG 153.21) may be used to install a temporary traffic control sign with a fluorescent orange background.

Guidance. Truck Entrance signs should be installed at locations where there is consistent and routine truck traffic entering and leaving a state route where the road user’s sight distance is restricted, and the crossing would be unexpected based on engineering judgement.

The truck entrance for which the sign is being installed should be recognizable by the presence of a on premise business marquee sign, building with the business name or some other form of marking to allow drivers associate the warning sign to the site where trucks could be entering or leaving the highway.

Standard. If used, the Truck Entrance sign shall be placed in accordance with Table 903.3.4.

The Truck Entrance sign shall only be installed for the direction of travel where the road user’s sight distance is restricted.

The truck entrance warning sign shall not be used on state highways at intersections with city streets or county roads, to address issues at these types of intersections other warning signs, such as Intersection Warning signs are more appropriate.

903.3.51 Farm Equipment (W11-5) Warning Sign

Option. Farm Equipment Warning (W11-5) signs may be used to alert road users to locations where unexpected entries into the roadway by farm equipment crossing the road might occur.

Guidance. W11-5 signs should be used only at locations where the road user’s sight distance is restricted, and the condition, activity, or entering traffic would be unexpected.

Support. The Farm Equipment (W11-5) sign is used to alert road users to locations where slow-moving farm vehicles are routinely entering or crossing the state highway (immediately across or a short transition down the road to a different entrance) if the highway splits the farm. A typical example would be a dairy farm where these crossings take place daily. In these cases, fluorescent yellow warning signs are installed in a permanent installation.

Farm Equipment signs are not installed to warn of farm equipment traveling along a state highway. This warning is the responsibility of the farmer and can be addressed by displaying the appropriate warning lights and signs on the equipment as well as having the appropriate lead and/or trailing vehicles escorting the equipment.

Option. For cases involving a temporary farm equipment access entrance, such as during planting or harvest season, a TR12 Truck Crossing agreement (see EPG 153.21) may be used to install a temporary traffic control sign with a fluorescent orange background.

Guidance. Farm Equipment signs should be installed at locations where there is consistent and routine farm equipment entering and leaving a state route where the road user’s sight distance is restricted, and the crossing would be unexpected based on engineering judgement.

The farm vehicle entrance for which the warning sign is being installed should be recognizable by the presence of a on-premise business marquee sign, presence of farm equipment, farm structures or other indicators to allow drivers to associate the warning sign to the site where farm vehicles could be crossing/entering the highway.

Standard. If used, the Farm Equipment warning sign shall be placed in accordance with Table 903.3.4.

The Farm Equipment warning sign shall only be installed for the direction of travel where the road user’s sight distance is restricted.

903.3.52 Emergency Vehicle (W11-8) Sign

Option. Emergency Vehicle (W11-8) signs may be used to alert road users to locations where unexpected entries into the roadway by emergency vehicles might occur.

Guidance. Emergency Vehicle signs should be used only at locations where the road user’s sight distance is restricted, and the condition, activity, or entering traffic would be unexpected.

Support. The Emergency Vehicle sign is used to alert road users to locations where emergency vehicles are routinely entering and leaving a state highway at dedicated emergency vehicle facility entrances.

Guidance. Emergency Vehicle signs should be installed at a state route where the road user’s sight distance is restricted, and the crossing would be unexpected based on engineering judgement.

The emergency vehicle entrance for which the warning sign is being installed should be recognizable by the presence of a on premise marquee sign, building with the emergency agency name displayed or some other form of marking to allow drivers to associate the warning sign to the site/entrance where emergency vehicles could be entering or leaving the state highway.

Standard. If used, the Emergency Vehicle warning sign shall be placed in accordance with Table 903.3.4.

The Emergency Vehicle warning sign shall only be installed for the direction of travel where the road user’s sight distance is restricted.

When measuring sight distance for emergency vehicle entrances, the sight distance shall be determined using a 3.5 ft. eye height and an 8 ft. object height in the same method use to evaluate school bus stop sight distances (see EPG 908.2.4).

The Emergency Vehicle sign with the EMERGENCY SIGNAL AHEAD (W11-12P) supplemental plaque shall be placed in advance of all emergency-vehicle traffic control signals (see EPG 902.13).

903.3.53 Non-Vehicular Warning Signs (W11-2, W11-3, W11-4, and W11-7) (MUTCD Section 2C.55)

Option. Non-Vehicular Warning (W11-2, W11-4, and W11-7) signs may be used to alert road users in advance of locations where unexpected entries into the roadway might occur.

Support. These conflicts might be relatively confined or might occur randomly over a segment of roadway.

Guidance. If used in advance of a pedestrian or equestrian crossing, the W11-2 and W11-7, signs should be supplemented with plaques (see EPG 903.3.59) with the legend AHEAD or XX FEET to inform road users that they are approaching a point where crossing activity might occur.

Standard. If a post-mounted W11-2 or W11-7 sign is placed at the location of the crossing point where pedestrians or equestrians might be crossing the roadway, a diagonal downward-pointing arrow (W16-7P) plaque (see EPG 903.3.62) shall be mounted below the sign. If the W11-2 or W11-7 sign is mounted overhead, the W16-7P plaque shall not be used.

A Non-Vehicular Warning sign assembly shall not be installed on an approach controlled by a STOP or a YIELD sign, except as provided in the first two Option paragraphs below.

Equestrian (W11-7) warning signs shall only be installed at Public Equestrian Trail Crossings. Existing Equestrian (W11-7) Crossing signs that do not meet the Public Equestrian Trail Crossing criteria shall be left in place until they reach the end of their service life.

The use of the Deer (W11-3) warning signs has been discontinued by MoDOT due to studies proving these signs provide little or no safety benefit. Existing W11-3 signs shall be removed at the end of their service life.

The Cattle (W11-4) sign shall be issued to an individual only when the Application for Sign at Cattle Crossings contract (TR09) is fully executed. See EPG 153.21 for the TR09 Agreement.

Option. The Non-Vehicular Warning sign assembly may be installed on an approach to a circular intersection controlled by a YIELD sign where the crosswalk is at least 20 feet in advance of the yield point at the entrance to a circulatory roadway.

At a signalized or stop-controlled intersection the Non-Vehicular Warning sign assembly may be installed on an approach to a channelized right-turn lane controlled by a YIELD sign where the crosswalk is at least 20 feet in advance of the yield point.

A Pedestrian Crossing (W11-2) sign may be placed overhead or may be post-mounted with a diagonal downward-pointing arrow (W16-7P) plaque at the crosswalk location where Yield Here To Pedestrians signs (see EPG 903.2.18) have been installed in advance of the crosswalk.

Standard. If a W11-2 sign has been post-mounted at the crosswalk location where a Yield Here To Pedestrians sign is used on the approach, the Yield Here To Pedestrians sign shall not be placed on the same post as the W11-2 sign.

Option. An advance Pedestrian Crossing (W11-2) sign with an AHEAD or a distance supplemental plaque may be used in conjunction with a Yield Here To Pedestrians sign on the approach to the same crosswalk.

The crossing location identified by a W11-2 or W11-7 sign may be defined with crosswalk markings (see EPG 620.3).

Standard. The W11-2 sign and related supplemental plaques shall only have a fluorescent yellow-green background with a black legend and border if the signs are installed within a school area as described in the fifth Support paragraph of EPG 903.3.2.

Guidance. When a fluorescent yellow-green background is used, a systematic approach featuring one background color within a zone or area should be used. The mixing of standard yellow and fluorescent yellow-green backgrounds within a selected site area should be avoided.

Option. A Warning Beacon (see EPG 902.18.3) may be used with any Non-Vehicular Warning sign to indicate specific periods when the condition or activity is present or is likely to be present, or to provide enhanced sign conspicuity.

903.3.54 FERRY CROSSING AHEAD Sign (W3-18)

Option. The FERRY CROSSING AHEAD (W3-18) sign may be installed for a ferry crossing. A STOP (R1-1) sign at the ferry crossing may be used as a supplement.

903.3.55 Passing Lane Warning Signs (W6-5, W6-5a, W6-6aP, W6-16, and W6-17)

W6-6aP

Support. Alternating passing lanes may be provided on rural, two-lane highways to provide motorists with an opportunity to pass slower vehicles without crossing the centerline. Where passing lanes are provided, operations and safety may be improved by giving motorists advance information about the location of passing lanes. Providing motorists with advance notice of passing lanes may reduce the number of passing maneuvers.

Standard. The PASSING LANE ENDS (W6-16), WATCH FOR LEFT-TURNING TRAFFIC IN PASSING LANE (W6-17), and PASSING LANE PLAQUE (W6-6aP) signs shall be black legend and fluorescent yellow background and shall only be used in alternating passing lane sections.

The PASSING LANE ENDS sign shall be used prior to the end of the passing lane to warn motorists the passing lane in that direction of travel is ending and merging back to a single lane. The sign shall be placed in advance of the LANE ENDS MERGE RIGHT (W9-2) sign at a distance determined by Table 903.3.4.

Option. The WATCH FOR LEFT TURNING TRAFFIC IN PASSING LANE sign may be used at locations in a passing lane segment where left turns are common, such as at a county road. This sign may be installed at the judgement of the engineer.

The Two-Way Traffic on a Three-Lane Roadway (W6-5 and W6-5a) signs may be installed along three-lane roadways with two lanes in one direction and one in the opposing direction.

903.3.56 TRAVEL SAFE ZONE – FINES DOUBLED Sign (W27-1)

Support. The TRAVEL SAFE ZONE - FINES DOUBLED (W27-1) sign is not to be used on a system-wide basis. It is intended for special use at locations where severe crashes are occurring. There is a requirement for regional support to focus a safety campaign involving local law enforcement and public information efforts to reduce the number and severity of crashes within the travel safe zone (see EPG 907.3).

Standard. A TRAVEL SAFE ZONE – FINES DOUBLED sign shall be used to mark the beginning of a designated travel safe zone. This sign is installed in conjunction with the FINES DOUBLED ENDS (R2-20) sign (see EPG 903.2.70).

903.3.57 Use of Supplemental Warning Plaques (MUTCD Section 2C.57)

Option. A supplemental warning plaque may be displayed with a warning or regulatory sign when engineering judgment indicates that road users require additional warning information beyond that contained in the main message of the warning or regulatory sign.

Standard. Supplemental warning plaques shall be used only in combination with and installed on the same post(s) as warning or regulatory signs. They shall not be mounted alone or displayed alone.

Unless otherwise provided in the EPG for a particular plaque, supplemental warning plaques shall be mounted below the sign they supplement.

903.3.58 Design of Supplemental Warning Plaques (MUTCD Section 2C.58)

Standard. A supplemental warning plaque used with a warning sign shall have the same legend, border, and background color as the warning sign with which it is displayed. A supplemental warning plaque used with a regulatory sign shall have a black legend and border on a yellow background.

Supplemental warning plaques shall be square or rectangular.

903.3.59 Advisory Speed Plaque (W13-1P) and Confirmation Advisory Speed Plaque (W13-1aP) (MUTCD Section 2C.59)

Option. The Advisory Speed (W13-1P) plaque may be used to supplement an advance warning sign to indicate the advisory speed for a condition.

The Confirmation Advisory Speed (W13-1aP) plaque may be used to supplement a One-Direction Large Arrow (W1-6) sign on the outside of a turn or curve in line with and at approximately a right angle to approaching traffic.

Standard. The use of the Advisory Speed and Confirmation Advisory Speed plaques for horizontal curves shall be in accordance with EPG 903.3.6. The Advisory Speed plaque shall also be used where an engineering study indicates a need to advise road users of the advisory speed for other roadway conditions.

The speed displayed on the Advisory Speed and Confirmation Advisory Speed plaques shall be a multiple of 5 mph. The maximum advisory speed posted shall never be more than the posted speed limit.

Except in emergencies or when the condition is temporary, an Advisory Speed or Confirmation Advisory Speed plaque shall not be installed until the advisory speed has been determined by an engineering study.

The Advisory Speed plaque shall only be used to supplement an advance warning sign. The Advisory Speed plaque or the Confirmation Advisory Speed plaque shall not be installed as a separate sign installation.

Guidance. The Advisory Speed plaque, if used with a sign that is also supplemented with another plaque, such as an Advance Street Name plaque (see EPG 903.3.64), should be mounted immediately below the primary warning sign with any other plaque mounted below the Advisory Speed plaque.

Standard. The Confirmation Advisory Speed plaque shall only be used to supplement a One-Direction Large Arrow (W1-6) sign (see EPG 903.3.10) or an Exit Gore (E5-1 series) sign (see EPG 903.5.26) and shall not be installed as a separate sign installation.

The advisory speed shall be determined by an engineering study that follows established engineering practices.

Guidance. The advisory speed should be determined based on free-flowing traffic conditions.

Because changes in conditions, such as roadway geometrics, surface characteristics, or sight distance, might affect the advisory speed, each location should be evaluated periodically or when conditions change.

Support. Among the established engineering practices that are appropriate for the determination of the recommended advisory speed for a horizontal curve are the following:

A. Accelerometer method

B. 10 degrees of ball bank for all speeds

Engineering Study for Ball-Banking The procedure to determine the safe speed on a curve or turn is a ball-bank study. To correctly use the ball-bank indicator, the ball-bank indicator should be mounted on the dashboard of a passenger car and adjusted to read "0" when the car is stationary on a level grade with the ball-bank indicator being in a vertical plane. When adjusting the indicator, all personnel who are to be in the car while testing should be in their seats and all four tires should have the same pressure. It is usually best for at least two persons to be in the car while taking the ball-bank reading: one for driving, the other for observation and recording. The 10-degree reading that can be maintained the complete length of a curve is the appropriate safe speed for that curve. Care must be taken to maintain the car in its proper lane and to maintain a smooth, consistent speed throughout the curve. It will occasionally be found that a curve will have a higher safe speed in one direction than the other. In such cases, the lower safe speed should be used for both directions. Only increments of 5 mph are used on the Advisory Speed Plaque, therefore the curve shall be posted to the nearest 5 mph speed from the survey.

903.3.60 Distance Plaques (W16-2P, W16-3P, W16-4P, and W7-3aP) (MUTCD Section 2C.61)

Option. The Distance Ahead (W16-2P and W16-3P) plaques may be used to inform the road user of the distance to the condition indicated by the warning sign.

The Next Distance (W7-3aP and W16-4P) plaques may be used to inform road users of the length of roadway over which the condition indicated by the warning sign exists.

Standard. Distances shall be shown in ¼ mile or 100 ft. increments. If the distance is less than a ½ mile then feet shall be used.

903.3.61 Supplemental Arrow Plaques (W16-5P and W16-6P) (MUTCD Section 2C.62)

Guidance. If the condition indicated by a warning sign is located on an intersecting road and the distance between the intersection and condition is not sufficient to provide adequate advance placement of the warning sign, a Supplemental Arrow (W16-5P or W16-6P) plaque should be used below the warning sign.

Standard. Supplemental Arrow plaques shall have the same legend design as the Advance Turn Arrow and Directional Arrow auxiliary signs (see EPG 903.4.22 and 903.4.24) except that they shall have a black legend and border on a fluorescent yellow or fluorescent yellow-green background, as appropriate.

903.3.62 Diagonal Downward-Pointing Arrow Plaques (W16-7P and W16-7aP) (MUTCD Section 2C.63)

Support. Diagonal downward-pointing arrow (W16-7P and W16-7aP) plaques are used with certain Vehicular Traffic Warning signs and certain Non-Vehicular Warning signs (see EPG 903.3.53), and School Crossing signs (see EPG 908.2.3) to indicate the specific location of a crossing point.

The W16-7P plaque contains a single arrow pointing diagonally down to the right or left, toward the roadway, depending on which side of the roadway it is located.

Option. A W16-7aP plaque may be used with a single crossing sign located on a narrow median separating two roadways with traffic in the same direction where the crossing traverses both roadways.

903.3.63 Hill-Related Plaques (W7-3 Series) (MUTCD Section 2C.64)

Guidance. Hill-Related (W7-3 series) plaques (see EPG 903.3.14) or other appropriate legends and larger signs should be used for emphasis or where special hill characteristics exist.

On longer grades, the use of a distance (W7-3aP) plaque (see EPG 903.3.14) at periodic intervals of approximately 1-mile spacing should be considered.

903.3.64 Advance Street Name Plaques (W16-8P and W16-8aP) (MUTCD Section 2C.65)

W16-8P

Support. Advance street name signing can provide valuable information to the motorist. Intersections that are signed with Intersection Warning (W2 series) or Advance Traffic Control (W3 series) signs typically have inherent sight distance concerns. The addition of the street name to the warning sign can aid a motorist in making decisions in a timely manner.

Option. An Advance Street Name (W16-8P or W16-8aP) plaque may be used with any Intersection (W1-10 series, W2 series, W10-2, W10-3, or W10-4) or Advance Traffic Control (W3 series) sign to identify the name of the intersecting street.

If the side road being signed is maintained by a public agency, the addition of the street name sign may be considered on request.

Standard. The lettering on Advance Street Name plaques shall be composed of a combination of lower-case letters with initial upper-case letters.

If two street names are used on the Advance Street Name plaque, a directional arrow pointing in the direction of the street shall be placed next to each street name. Arrows pointing to the left shall be placed to the left of the street name, and arrows pointing to the right shall be placed to the right of the street name.

The street name used on an Advance Street Name supplemental sign shall be the approved name used by either the local agency or the Emergency 911 Coordinator.

When used, the Advance Street Name supplemental plaque shall only be mounted below the W2 or W3 series warning sign or the Advisory Speed plaque on the same post.

The Advance Street Name supplemental plaque for a 36 in. x 36 in. warning sign shall be a maximum of 36 in. wide and for a 48 in. x 48 in. warning sign shall be a maximum of 48 in. wide.

Guidance. If two street names are used on the Advance Street Name plaque, the street names and associated arrows should be displayed in the following order:

A. For a single intersection, the name of the street to the left should be displayed above the name of the street to the right; or

B. For two sequential intersections, such as where the plaque is used with an Offset Side Roads (W2-7) or a Double Side Road (W2-8) sign, the name of the first street encountered should be displayed above the name of the second street encountered, and the arrow associated with the second street encountered should be an advance arrow, such as the arrow shown on the W16-6P arrow plaque (see EPG 903.3.61).

903.3.65 Traffic Does Not Stop Plaques (W4-4P Series) (MUTCD Section 2C.66)

W4-4P

W4-4aP

W4-4bP

Option. The CROSS TRAFFIC DOES NOT STOP (W4-4P) plaque may be used in combination with a STOP sign when engineering judgment indicates that conditions are present that are causing or could cause road users to misinterpret the intersection as an all-way stop.

The TRAFFIC FROM LEFT (RIGHT) DOES NOT STOP (W4-4aP) or ONCOMING TRAFFIC DOES NOT STOP (W4-4bP) plaque may be used when such messages more accurately describe the traffic controls established at the intersection.

Guidance. The W4-4aP and W4-4bP plaques should be used at intersections where STOP signs control all but one approach to the intersection, unless the only non-stopped approach is from a one-way street.

Standard. If a W4-4P series plaque is used, it shall be mounted below the STOP sign.

903.3.66 IN ROAD and IN STREET Plaques (W16-1P) (MUTCD Section 2C.67)

Option. In situations where there is a need to warn drivers to watch for other slower forms of transportation traveling along the highway, such as bicycles or horse-drawn vehicles, an IN ROAD (W16-1P) plaque may be used.

Standard. The background color of the W16-1P plaque shall match the background color of the warning sign with which it is displayed. If a W16-1P plaque is used, it shall be mounted below a Bicycle (W11-1) or Horse-Drawn Vehicle (W11-14) warning signs and shall not be mounted alone.

Support. EPG 914.2.6 contains information about the use of a Bicycles Allowed Use of Full Lane (R9-20) sign to inform drivers of the presence of bicycles in the roadway or where bicyclists are expected or preferred to use the full lane.

903.3.67 NOTICE Plaque (W16-18p)

W16-18P

Support. It is sometimes necessary to enhance the conspicuity of a regulatory sign to attract drivers’ attention to the message the sign is conveying. This may be necessary to help notify drivers to a speed limit reduction, turning movement prohibition, or bridge weight restriction. The NOTICE (W16-18P) plaque is an alternate to the use of red flags (see EPG 903.1.11).

Standard. The NOTICE (W16-18P) plaque shall not be used alone.

When used, the NOTICE plaque shall be installed directly above the regulatory sign it is enhancing.

Guidance. The use of the NOTICE (W16-18P) plaque should be based on engineering judgment and not systematically applied to a specific sign unless otherwise specified in the EPG.

903.3.68 Exception Plaques (W16-23P and W16-24P)

Support. The EXCEPT TO TURN (W16-23P) supplemental warning plaque is used with the NO TRUCKS LEFT LANE (R5-32) regulatory sign (see EPG 903.2.36) in locations where trucks are not allowed to drive in the left lane, but are allowed to enter the left lane in order to make a turn. The EXCEPT TO EXIT (W16-24P) supplemental warning plaque is used with the NO TRUCKS LEFT LANE (R5-32) regulatory sign in locations where trucks are not allowed to drive in the left lane, but trucks are allowed to enter the left lane in order to exit the highway.

Standard. When used, the EXCEPT TO TURN (W16-23P) and EXCEPT TO EXIT (W16-24P) supplemental warning plaques shall only be installed in conjunction with the FINES DOUBLED ENDS (R2-20) sign (see EPG 903.2.70).

903.3.69 Warning Signs Provided for Other Agencies

Support. MoDOT will provide, if requested by the appropriate local traffic authority, warning signs for conditions beyond the end of state-maintained right of way.

If the location for placement of an advance warning sign for a curve, turn, paved road, stop condition or other condition deemed appropriate falls on state-maintained right of way, MoDOT will place and maintain the traffic control device on state-maintained right-of-way at the request of the local traffic authority.

Standard. The placement of all traffic control devices on the state highway system shall be governed by the Engineering Policy Guide. MoDOT is responsible for the placement and maintenance of all signs on state-maintained right-of-way.

903.3.70 Object Marker Design and Placement Height (MUTCD Section 2C.70)

Support. Types 1, 2, and 3 object markers are used to mark obstructions within or adjacent to the roadway. Type 4 object markers are used to mark the end of a roadway.

Standard. When used, object markers (see Figure 903.3.70) shall not have a border and shall consist of an arrangement of one or more of the following types:

Type 1—a diamond-shaped sign, at least 18 inches on a side, consisting of an all-yellow retroreflective sign (OM1-3).

Type 2—an all-yellow horizontal or vertical retroreflective sign (OM2-2V or OM2-2H), measuring 6 x 12 inches.

Type 3—a striped marker, 12 x 36 inches, consisting of a vertical rectangle with alternating black and retroreflective yellow stripes sloping downward at an angle of 45 degrees toward the side of the obstruction on which traffic is to pass. The minimum width of the yellow and black stripes shall be 3 inches.

Type 4—a diamond-shaped sign, at least 18 inches on a side, consisting of an all-red retroreflective sign (OM4-3).

Support. Type 3 object markers with stripes that begin at the upper right side and slope downward to the lower left side are designated as right object markers (OM3-R). Object markers with stripes that begin at the upper left side and slope downward to the lower right side are designated as left object markers (OM3-L). Object markers with chevron stripes that slope downward to both the lower left and lower right sides are designated as center object markers (OM3-C).

Guidance. When used for marking obstructions within the roadway or obstructions that are 8 feet or less from the shoulder or curb, the minimum mounting height, measured from the bottom of the object marker to the elevation of the near edge of the traveled way, should be 4 feet.

When used to mark obstructions more than 8 feet from the shoulder or curb, the clearance from the ground to the bottom of the object marker should be at least 4 feet.

Object markers should not present a vertical or horizontal clearance obstacle for pedestrians.

Option. When object markers or markings are applied to an obstruction that by its nature requires a lower or higher mounting, the vertical mounting height may vary according to need.

903.3.71 Object Markers for Obstructions Within the Roadway (MUTCD Section 2C.71)

Standard. Obstructions within the roadway shall be marked with a Type 1 or Type 3 object marker. In addition to markers on the face of the obstruction, warning of approach to the obstruction shall be given by appropriate pavement markings (see EPG 620.2.15).

Option. To provide additional emphasis, a Type 1 or Type 3 object marker may be installed at or near the approach end of a median island.

To provide additional emphasis, large surfaces such as bridge piers may be painted with diagonal stripes, 12 inches or greater in width, similar in design to the Type 3 object marker.

Standard. The alternating black and retroreflective yellow stripes (OM3-L, OM3-R) shall be sloped down at an angle of 45 degrees toward the side on which traffic is to pass the obstruction. If traffic can pass to either side of the obstruction, the alternating black and retroreflective yellow stripes (OM3-C) shall form chevrons that point upwards.

Option. Appropriate signs (see EPG 903.2.34 and 903.3.20) directing traffic to one or both sides of the obstruction may be used instead of the object marker.

903.3.72 Object Markers for Obstructions Adjacent to the Roadway (MUTCD Section 2C.72)

Support. Obstructions not actually within the roadway are sometimes so close to the edge of the road that they need a marker. These include underpass piers, bridge abutments, handrails, ends of traffic barriers, utility poles, and culvert headwalls. In other cases there might not be a physical object involved, but other roadside conditions exist, such as narrow shoulders, drop-offs, gores, small islands, and abrupt changes in the roadway alignment, that might make it undesirable for a road user to leave the roadway, and therefore would create a need for a marker.

Standard. Type 3 object markers shall be used to mark all obstructions within 3 feet of the edge of the travel lane or edge of the shoulder when shoulders are present (paved or aggregate). Type 3 object markers shall not be used to mark obstructions located beyond 8 feet of the edge of the travel lane or edge of the shoulder. See Figures 903.3.72.1 and 903.3.72.2 for standard applications of Type 3 object markers.

Option. Type 3 object markers may be used to mark obstructions located 3 feet to 8 feet from the edge of the travel lane or edge of the shoulder based on engineering judgment. See Figures 903.3.72.1 and 903.3.72.2 for standard applications of Type 3 object markers.

Guidance. If a Type 2 or Type 3 object marker is used to mark an obstruction adjacent to the roadway, the edge of the object marker that is closest to the road user should be installed in line with the closest edge of the obstruction.

When a marker is applied to the approach ends of guardrail or crash cushion terminals it should have the appearance of a Type 3 object marker and should be directly affixed, without a substrate, to the approach end of the guardrail or crash cushion and generally conform to the size and shape of the approach end of the guardrail or crash cushion.

Standard. Type 1 and Type 4 object markers shall not be used to mark obstructions adjacent to the roadway.

Guidance. Standard warning signs in this Chapter should also be used where applicable.

903.3.73 Object Markers for Ends of Roadways (MUTCD Section 2C.73)

Support. The Type 4 object marker is used to warn and alert road users of the end of a roadway in other than construction or maintenance areas.

Standard. If an object marker is used to mark the end of a roadway, a Type 4 object marker shall be used. See (Section 903 of the Missouri Standard Plans for Highway Construction) for installation details.

Option. The Type 4 object marker may be used in instances where there are no alternate vehicular paths.

Standard. The minimum mounting height, measured vertically from the bottom of a Type 4 object marker to the elevation of the near edge of the traveled way, shall be 4 feet.

Guidance. Appropriate advance warning signs in EPG 903.3 should be used.

903.3.74 Shoulder Barricade Assembly

Option. Shoulder barricades may be used for added emphasis of standard warning sign installations at the direction of the engineer.

Standard. The shoulder barricade assembly shall consist of three horizontal boards (GB-1L or GB-1R) marked with reflective diagonal stripes and a 48-inch standard warning sign and a 48 in. standard warning sign with the appropriate 30-inch advisory plaque. See Figure 903.3.74 for typical construction.

GB-1R shoulder barricades shall be installed on the right side of the roadway and have diagonal stripes sloping downward from the right to the left.

GB-1L shoulder barricades shall be installed on the left side of the roadway and have diagonal stripes sloping downward from the left to the right.

Option. Supplemental signs may be installed on the shoulder barricade at the direction of the engineer.

Guidance. Shoulder Barricades should be installed on the appropriate size on wide flanged structural steel posts.

**Figure 903.3.74** Shoulder Barricade Assembly