902.8 Traffic Control Signals and Hybrid Beacons for Emergency Vehicle Access (MUTCD Chapter 4G)
- 1 902.8.1 Application of Emergency-Vehicle Traffic Control Signals and Hybrid Beacons (MUTCD Section 4G.01)
- 2 902.8.2 Design of Emergency-Vehicle Traffic Control Signals (MUTCD Section 4G.02)
- 3 902.8.3 Operation of Emergency-Vehicle Traffic Control Signals (MUTCD Section 4G.03)
- 4 902.8.4 Emergency-Vehicle Hybrid Beacons (MUTCD Section 4G.04)
902.8.1 Application of Emergency-Vehicle Traffic Control Signals and Hybrid Beacons (MUTCD Section 4G.01)
Support. An emergency-vehicle traffic control signal is a special traffic control signal that assigns the right of way to an authorized emergency vehicle.
Standard. Consideration for the installation of an emergency vehicle signal is only given when an emergency vehicle facility is located on a state highway and the emergency vehicle, upon leaving the facility, enters directly onto that highway.
Option. An emergency-vehicle traffic control signal may be installed at a location that does not meet other traffic signal warrants such as at an intersection or other location to permit direct access from a building housing the emergency vehicle.
An emergency-vehicle hybrid beacon may be installed instead of an emergency-vehicle traffic control signal under conditions described in EPG 902.8.4.
Guidance. If a traffic control signal is not justified under the signal warrants of EPG 902.3 Traffic Control Signal Needs Studies and if gaps in traffic are not adequate to permit the timely entrance of emergency vehicles, or the stopping sight distance for vehicles approaching on the major street is insufficient for emergency vehicles, installing an emergency-vehicle traffic control signal should be considered. If one of the signal warrants of EPG 902.3 is met and a traffic control signal is justified by an engineering study, and if a decision is made to install a traffic control signal, it should be installed based upon the provisions of EPG 902.5 Traffic Control Signal Features.
The sight distance determination should be based on the location of the visibility obstruction for the critical approach lane for each street or drive and the posted or statutory speed limit or 85th-percentile speed on the major street, whichever is higher.
Standard. For a new emergency vehicle signal installation, the emergency entity, city, or other organization having control over the emergency equipment, will be required to pay the full cost of construction and will be required to maintain the equipment.
Guidance. The MoDOT district uses the applicant's request and supporting data to approve the installation. If approval is given, a contract is executed between the Missouri Highway and Transportation Commission and the proper local authorities or organization that covers the installation, maintenance, and operation of such a signal.
Normally a push button is located in the emergency facility. The push button and the connection (wireless or wired) to the signal will be provided and maintained by the emergency facility.
Standard. Upon completion of the installation, the requesting party will be responsible for all maintenance, replacement costs, and power costs.
Support. The TR06 Emergency Vehicle Signal Agreement is the standard agreement to be used.
See EPG 902.5.38 for preemption.
902.8.2 Design of Emergency-Vehicle Traffic Control Signals (MUTCD Section 4G.02)
Standard. Except as otherwise provided in this article, an emergency-vehicle traffic control signal shall meet the requirements of EPG 902.
An Emergency Vehicle (W11-8) sign (see EPG 903.6.40) with an EMERGENCY SIGNAL AHEAD (W11-12P) supplemental plaque shall be placed in advance of all emergency-vehicle traffic control signals. If a warning beacon is installed to supplement the W11-8 sign, the design and location of the beacon shall comply with the Standards of EPG 902.12.1 and EPG 902.12.3.
Guidance. At least one of the two required signal faces for each approach on the major street should be located horizontally over the roadway. Also, at least one signal head faces the direction of approach of the emergency vehicle.
Standard. The following size signal indications shall be used for emergency-vehicle traffic control signals on the major street: 12 in. diameter for steady red and steady yellow circular signal indications and any arrow indications, and 8 in. diameter for flashing yellow circular signal indications.
The indications for the approach of the emergency vehicle shall be a 12 in. steady red and a 12 in. green.
Standard. An EMERGENCY SIGNAL (R10-13) sign shall be mounted adjacent to a signal face on each major street approach (see MUTCD Section 2B.53). If an overhead signal face is provided, the EMERGENCY SIGNAL sign shall be mounted adjacent to the overhead signal face.
Option. An approach that only serves emergency vehicles may be provided with only one signal face consisting of two or more signal sections.
Support. See Typical Emergency Vehicle Signal Layouts and Figure 902.8.2, below, for standard emergency vehicle signal installation.
902.8.3 Operation of Emergency-Vehicle Traffic Control Signals (MUTCD Section 4G.03)
Standard. Right of way for emergency vehicles at signalized locations operating in the steady (stop-and-go) mode shall be obtained as provided in EPG 902.5.38 Preemption and Priority Control of Traffic Control Signals.
As a minimum, the signal indications, sequence, and manner of operation of an emergency-vehicle traffic control signal installed at a midblock location shall be as follows:
- A. The signal indication, between emergency-vehicle actuations, shall be flashing yellow. The flashing yellow signal indication shall be displayed in the normal position of the green signal indication, while the steady red and steady yellow signal indications shall be displayed in their normal positions.
- B. When an emergency-vehicle actuation occurs, a steady yellow change interval followed by a steady red interval shall be displayed to traffic on the major street.
- C. A yellow change interval is not required following the green interval for the emergency-vehicle driveway.
Emergency-vehicle traffic control signals located at intersections shall either be operated in the flashing mode between emergency-vehicle actuations (see EPG 902.5.39 Flashing Operation of Traffic Control Signals – General through EPG 902.5.42 Flashing Operation – Transition Out of Flashing Mode and Typical Emergency Vehicle Signal Layouts) or be full-actuated or semi-actuated to accommodate normal vehicular and pedestrian traffic on the streets. Warning beacons, if used with an emergency-vehicle traffic control signal, shall be flashed only:
- A. For an appropriate time in advance of and during the steady yellow change interval for the major street; and
- B. During the steady red interval for the major street.
Guidance. The duration of the steady red interval for traffic on the major street should be determined by on-site test-run time studies but should not exceed 1.5 times the time required for the emergency vehicle to clear the path of conflicting vehicles.
Option. An emergency-vehicle traffic control signal sequence may be initiated manually from a local control point such as a fire station, law enforcement headquarters or other emergency vehicle facility or from an emergency vehicle equipped for remote operation of the signal.
902.8.4 Emergency-Vehicle Hybrid Beacons (MUTCD Section 4G.04)
Standard. Emergency-vehicle hybrid beacons shall be used only in conjunction with signs to warn and control traffic at an unsignalized location where emergency vehicles enter or cross a street or highway. Emergency-vehicle hybrid beacons shall be actuated only by authorized emergency or maintenance personnel.
Guidance. Emergency-vehicle hybrid beacons should only be used when all the following criteria are satisfied:
- A. The conditions justifying an emergency-vehicle traffic control signal (see EPG 902.8.1) are met; and
- B. An engineering study, considering the road width, approach speeds, and other pertinent factors, determines that emergency-vehicle hybrid beacons can be designed and located in compliance with the requirements contained in this article and in EPG 902.12.1, so that they effectively warn and control traffic at the location; and
- C. The location is not at or within 100 ft. from an intersection or driveway where the side road or driveway is controlled by a STOP or YIELD sign.
Standard. Except as otherwise provided in this article, an emergency-vehicle hybrid beacon shall meet the requirements of EPG 902.
An emergency-vehicle hybrid beacon face shall consist of three signal sections, with a CIRCULAR YELLOW signal indication centered below two horizontally aligned CIRCULAR RED signal indications (see Fig. 902.8.4).
Emergency-vehicle hybrid beacons shall be placed in a dark mode (no indications displayed) during periods between actuations.
Upon actuation by authorized emergency personnel, the emergency-vehicle hybrid beacon faces shall each display a flashing yellow signal indication, followed by a steady yellow change interval, prior to displaying two CIRCULAR RED signal indications in an alternating flashing array for a duration of time adequate for egress of the emergency vehicles. The alternating flashing red signal indications shall only be displayed when it is required that drivers on the major street stop and then proceed subject to the rules applicable after making a stop at a STOP sign. Upon termination of the flashing red signal indications, the emergency-vehicle hybrid beacons shall revert to a dark mode (no indications displayed) condition.
The duration of the flashing yellow interval should be determined by engineering judgment.
Standard. The duration of the steady yellow change interval shall be determined using engineering practices.
Guidance. The steady yellow change interval should have a minimum duration of 3 seconds and a maximum duration of 6 seconds (see EPG 902.5.36.2 Yellow Change and Red Clearance Intervals). The longer intervals should be reserved for use on approaches with higher speeds.
Option. A steady red clearance interval may be used after the steady yellow change interval.
Emergency-vehicle hybrid beacons may be equipped with a light or other display visible to the operator of the egressing emergency vehicle to provide confirmation that the beacons are operating.
Emergency-vehicle hybrid beacons may be supplemented with an advance warning sign, which may also be supplemented with a Warning Beacon EPG 902.12.3.
Standard. Warning beacons, if used with an emergency-vehicle hybrid beacon, shall be flashed only when the emergency-vehicle hybrid beacon is not in the dark mode.
Standard. At least two emergency-vehicle hybrid beacon faces shall be installed for each approach of the major street with at least one being overhead and a stop line shall be installed for each approach of the major street.
Guidance. On approaches having posted or statutory speed limits or 85th-percentile speeds in excess of 40 mph, and on approaches having traffic or operating conditions that would tend to obscure visibility of roadside beacon faces, both of the minimum of two emergency-vehicle hybrid beacon faces should be installed over the roadway.
An emergency-vehicle hybrid beacon should comply with the signal face location provisions described in EPG 902.5.17 through EPG 902.5.21.
Standard. Stop lines and EMERGENCY SIGNAL—STOP WHEN FLASHING RED (R10-14) signs (see MUTCD Section 2B.53) shall be used with emergency-vehicle hybrid beacons.
Option. If needed for extra emphasis, a STOP HERE ON FLASHING RED (R10-14b) sign (see MUTCD Section 2B.53) may be installed with an emergency-vehicle hybrid beacon.