233.5 Intersection Alternatives - Revision history

Hoskir: updated broken link

2026-01-26T16:29:32Z

updated broken link

← Older revision		Revision as of 11:29, 26 January 2026
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	[https://www.modot.org/roundabouts MoDOT Roundabouts]		[https://www.modot.org/roundabouts MoDOT Roundabouts]

	[https://www.~~trb~~.org/~~Publications~~/~~Blurbs/182939.aspx~~ NCHRP 1043 Guide for Roundabouts]		[https://www.nationalacademies.org/publications/27069 NCHRP 1043 Guide for Roundabouts]

	[https://highways.dot.gov/safety/intersection-safety/intersection-types/roundabouts FHWA Roundabouts]		[https://highways.dot.gov/safety/intersection-safety/intersection-types/roundabouts FHWA Roundabouts]

Hoskir: /* 233.5.1 Alternative Intersection Comparisons */ added pdf extension to links

2025-01-27T21:58:41Z

233.5.1 Alternative Intersection Comparisons: added pdf extension to links

Hoskir at 15:51, 24 January 2025

2025-01-24T15:51:05Z

← Older revision		Revision as of 10:51, 24 January 2025
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	[https://www.fhwa.dot.gov/publications/research/safety/09060/008.cfm FHWA Alternative Intersections/Interchanges: Informational Report (AIIR) Chapter 8]		[https://www.fhwa.dot.gov/publications/research/safety/09060/008.cfm FHWA Alternative Intersections/Interchanges: Informational Report (AIIR) Chapter 8]
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			[[Category:233 At - Grade Intersections]]

Hoskir at 22:03, 21 January 2025

2025-01-21T22:03:44Z

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	[https://www.fhwa.dot.gov/publications/research/safety/09060/008.cfm FHWA Alternative Intersections/Interchanges: Informational Report (AIIR) Chapter 8]		[https://www.fhwa.dot.gov/publications/research/safety/09060/008.cfm FHWA Alternative Intersections/Interchanges: Informational Report (AIIR) Chapter 8]
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Hoskir at 21:52, 21 January 2025

2025-01-21T21:52:09Z

← Older revision		Revision as of 16:52, 21 January 2025
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	[https://www.fhwa.dot.gov/publications/research/safety/09060/008.cfm FHWA Alternative Intersections/Interchanges: Informational Report (AIIR) Chapter 8]		[https://www.fhwa.dot.gov/publications/research/safety/09060/008.cfm FHWA Alternative Intersections/Interchanges: Informational Report (AIIR) Chapter 8]

	~~[[Category:233 At - Grade Intersections]]~~

Hoskir at 17:11, 21 January 2025

2025-01-21T17:11:06Z

← Older revision		Revision as of 12:11, 21 January 2025
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	[https://www.fhwa.dot.gov/publications/research/safety/09060/008.cfm FHWA Alternative Intersections/Interchanges: Informational Report (AIIR) Chapter 8]		[https://www.fhwa.dot.gov/publications/research/safety/09060/008.cfm FHWA Alternative Intersections/Interchanges: Informational Report (AIIR) Chapter 8]

			[[Category:233 At - Grade Intersections]]

Hoskir: updated per RR3964

2025-01-17T19:34:20Z

updated per RR3964

Show changes

Hoskir at 17:32, 17 January 2025

2025-01-17T17:32:33Z

@@ Line 71: / Line 71: @@
 There are several daily volumetric thresholds at which a given traffic control method at a traditional intersection may become infeasible and require further improvements.
-{| class="wikitable"
+{| class="wikitable" style="text-align: center;"
 ! !! Maximum Major Street Volume (vpd) !! Maximum Total Entering Volume (vpd)
 |-
@@ Line 190: / Line 190: @@
 | Vehicle-Vehicle - Diverging || 8 (8)
 |-
-|Nonmotorized-Vehicle 8 (24)
+| Nonmotorized-Vehicle || 8 (24)
-.5.3.8 High Speed Roundabout Design Considerations
+|}
 Roundabouts located on high-speed roadways may require special geometric and safety design
-considerations. Appropriate design related measures may include, but are not limited to:
+===233.5.3.8 High Speed Roundabout Design Considerations===
-• Provide a minimum of stopping sight distance to the entry point based on approach operating
+Roundabouts located on high-speed roadways may require special geometric and safety design considerations. Appropriate design related measures may include, but are not limited to:
-speed.
+* Provide a minimum of stopping sight distance to the entry point based on approach operating speed.
-• Align approach roadways and vertical profiles to make the central island conspicuous with
+* Align approach roadways and vertical profiles to make the central island conspicuous with landscaping and sight-blocking amenities.
-landscaping and sight-blocking amenities.
+* Extend splitter islands at least 200’ upstream to a point at which entering drivers are expected to begin decelerating.
-• Extend splitter islands at least 200’ upstream to a point at which entering drivers are
+* Use landscaping on extended splitter islands and roadside to create a tunneling effect for approaching vehicles.
-expected to begin decelerating.
+* Provide roadway illumination in transition to the roundabout.
-• Use landscaping on extended splitter islands and roadside to create a tunneling effect for
+* Use proper signage and pavement markings to advise the appropriate speed and path for approaching vehicles.
 approaching vehicles.
-• Provide roadway illumination in transition to the roundabout.
+===233.5.3.9 Roundabout Additional Resources===
-• Use proper signage and pavement markings to advise the appropriate speed and path for
+[[620.3_Roundabout_Markings_(MUTCD_Chapter_3C)|EPG 620.3 Roundabout Markings]]
 approaching vehicles.
-.5.3.9 Roundabout Additional Resources
+[[903.6_Warning_Signs#903.6.37_Intersection_Warning_Signs_.28W2-1_through_W2-8.29_.28MUTCD_Section_2C.46.29|EPG 903.6.37 Intersection Warning Signs]]
 EPG 620.3 Roundabout Markings
-EPG 903.6.37 Intersection Warning Signs
+[https://www.modot.org/roundabouts MoDOT Roundabouts]
 MoDOT Roundabouts
-NCHRP 1043 Guide for Roundabouts
+[https://www.trb.org/Publications/Blurbs/182939.aspx NCHRP 1043 Guide for Roundabouts]
 FHWA Roundabouts
-Level 2 - Issue 1 (Page 17 of
+[https://highways.dot.gov/safety/intersection-safety/intersection-types/roundabouts FHWA Roundabouts]

Hoskir at 16:47, 17 January 2025

2025-01-17T16:47:40Z

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 Conflict points for a 4-leg traditional intersection may be viewed in the table below and in the [https://epg.modot.org/forms/general_files/TS/233.5.2.2_Traditional_Intersection_Conflict.pdf Traditional Intersection Conflict Point Diagram].
-{| class="wikitable" style="text-align: center;
+{| class="wikitable" style="text-align: center;"
 ! Conflict Point Type !! Conflict Points
 |-
@@ Line 117: / Line 116: @@
 ===233.5.2.8 Traditional Intersection Additional Resources===
 [[233.4_At-Grade_Intersections_with_Signal_Control|EPG 233.4 At-Grade Intersections with Signal Control]]
 [[:Category:902_Signals|EPG 902 Signals]]
 [[:Category:940_Access_Management|EPG 940 Access Management]]
--->
+==233.5.3 Roundabouts==

Hoskir: partial update of RR3964

2025-01-17T15:19:02Z

partial update of RR3964

New page

← Older revision		Revision as of 16:58, 27 January 2025
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	The following figures provide potential guidance for alternative intersection selection either by the total entering daily volume for the intersection or by the peak two-way hourly volumes on the major and minor streets at the intersection.		The following figures provide potential guidance for alternative intersection selection either by the total entering daily volume for the intersection or by the peak two-way hourly volumes on the major and minor streets at the intersection.

	[https://epg.modot.org/forms/general_files/TS/233.5.1.1 Potential Intersection Control by Total Entering Daily Volume (ADT)] provides guidance for generic ADT-based scenarios under which a specific intersection control type could be used. The term “Non-traditional Intersection” refers to intersection types with unique geometrics or flow patterns. Non-traditional intersections considered by MoDOT include: Roundabouts, J-Turns (Restricted Crossing U-Turn Intersection (RCUT)/Reduced Conflict Intersection (RCI)), Median U-Turns (MUT), and Displaced Left Turns (DLT/Continuous Flow Intersection (CFI)).		[https://epg.modot.org/forms/general_files/TS/233.5.1.1.pdf Potential Intersection Control by Total Entering Daily Volume (ADT)] provides guidance for generic ADT-based scenarios under which a specific intersection control type could be used. The term “Non-traditional Intersection” refers to intersection types with unique geometrics or flow patterns. Non-traditional intersections considered by MoDOT include: Roundabouts, J-Turns (Restricted Crossing U-Turn Intersection (RCUT)/Reduced Conflict Intersection (RCI)), Median U-Turns (MUT), and Displaced Left Turns (DLT/Continuous Flow Intersection (CFI)).

	[https://epg.modot.org/forms/general_files/TS/233.5.1.2 Intersection Control Type by Peak Hour Volume Thresholds] utilizes the peak hour directional distribution splits and two-way traffic volumes for both the major and minor roadways to determine the most appropriate intersection treatment, with a primary focus on traditional intersection control types. All lines shown are defined by the MUTCD 8-hour traffic signal warrant, MUTCD all-way stop warrant, and HCM methods for calculating roundabout capacity and stop-controlled intersection delay. Dashed lines represent an extrapolation of a capacity threshold for a given intersection type and geometric configuration, such as comparing a single-lane roundabout to a multi-lane roundabout.		[https://epg.modot.org/forms/general_files/TS/233.5.1.2.pdf Intersection Control Type by Peak Hour Volume Thresholds] utilizes the peak hour directional distribution splits and two-way traffic volumes for both the major and minor roadways to determine the most appropriate intersection treatment, with a primary focus on traditional intersection control types. All lines shown are defined by the MUTCD 8-hour traffic signal warrant, MUTCD all-way stop warrant, and HCM methods for calculating roundabout capacity and stop-controlled intersection delay. Dashed lines represent an extrapolation of a capacity threshold for a given intersection type and geometric configuration, such as comparing a single-lane roundabout to a multi-lane roundabout.

	===233.5.1.3 Intersection Selection by Pedestrian and Bicyclist Safety Criteria===		===233.5.1.3 Intersection Selection by Pedestrian and Bicyclist Safety Criteria===
	The following figures present the optimum feasible intersection configuration choice (per original source research study, not through MoDOT determination) for pedestrians and bicyclists given the number of through lanes and daily traffic volumes on the minor and major streets.		The following figures present the optimum feasible intersection configuration choice (per original source research study, not through MoDOT determination) for pedestrians and bicyclists given the number of through lanes and daily traffic volumes on the minor and major streets.

	[https://epg.modot.org/forms/general_files/TS/233.5.1.3 Pedestrian Optimum Feasible Intersection Design]		[https://epg.modot.org/forms/general_files/TS/233.5.1.3.pdf Pedestrian Optimum Feasible Intersection Design]

	[https://epg.modot.org/forms/general_files/TS/233.5.1.4 Bicyclist Optimum Feasible Intersection Design]		[https://epg.modot.org/forms/general_files/TS/233.5.1.4.pdf Bicyclist Optimum Feasible Intersection Design]

	===233.5.1.4 Intersection Selection by Vehicular Safety Criteria===		===233.5.1.4 Intersection Selection by Vehicular Safety Criteria===
	The following figures show the intersection type that maximizes safety (per original source research study, not through MoDOT determination) based on various approach configurations and daily roadway volumes. Areas without a specific intersection type listed are either infeasible regions in which the minor street demand exceeds the major street demand, or where the alternative intersection types being considered are not feasible.		The following figures show the intersection type that maximizes safety (per original source research study, not through MoDOT determination) based on various approach configurations and daily roadway volumes. Areas without a specific intersection type listed are either infeasible regions in which the minor street demand exceeds the major street demand, or where the alternative intersection types being considered are not feasible.

	[https://epg.modot.org/forms/general_files/TS/233.5.1.5 Intersection Type that Maximizes Safety Design for a Four-Lane Major Street Meeting a Two-Lane Minor Street]		[https://epg.modot.org/forms/general_files/TS/233.5.1.5.pdf Intersection Type that Maximizes Safety Design for a Four-Lane Major Street Meeting a Two-Lane Minor Street]

	[https://epg.modot.org/forms/general_files/TS/233.5.1.6 Intersection Type that Maximizes Safety Design for a Four-Lane Major Street Meeting a Four-Lane Minor Street]		[https://epg.modot.org/forms/general_files/TS/233.5.1.6.pdf Intersection Type that Maximizes Safety Design for a Four-Lane Major Street Meeting a Four-Lane Minor Street]

	[https://epg.modot.org/forms/general_files/TS/233.5.1.7 Intersection Type that Maximizes Safety Design for a Six-Lane Major Street Meeting a Two-Lane Minor Street]		[https://epg.modot.org/forms/general_files/TS/233.5.1.7.pdf Intersection Type that Maximizes Safety Design for a Six-Lane Major Street Meeting a Two-Lane Minor Street]

	==233.5.2 Traditional Intersections==		==233.5.2 Traditional Intersections==