902.14 Hybrid Beacons for Emergency-Vehicle Access (MUTCD Chapter 4N)
902.14.1 Application of Emergency-Vehicle Hybrid Beacons (MUTCD Section 4N.01)
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 of the following criteria are satisfied:
- A. The conditions justifying an emergency-vehicle traffic control signal (see EPG 902.13.1) are met;
- 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 902.18.1, such that they effectively warn and control traffic at the location; and
- C. The location is not at or within 100 feet from an intersection or driveway where the side road or driveway is controlled by a STOP or YIELD sign.
902.14.2 Design of Emergency-Vehicle Hybrid Beacons (MUTCD Section 4N.02)
Standard. Except as otherwise provided in this Article, an emergency-vehicle hybrid beacon shall meet the requirements of the EPG.
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 Figure 902.14.2).
At least two emergency-vehicle hybrid beacon faces shall be installed for each approach of the major street and at least one of the emergency-vehicle hybrid beacon faces shall be installed over the roadway.
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 Sections EPG 902.4.5 through EPG 902.4.10.
Standard. Stop lines and EMERGENCY SIGNAL—STOP ON FLASHING RED (R10-14 or R10-14a) signs (see EPG 903.2.48) shall be used with emergency-vehicle hybrid beacons for each approach of the major street.
Option. If needed for extra emphasis, a STOP HERE ON FLASHING RED (R10-14b) sign (see EPG 903.2.48) may be installed with an emergency-vehicle hybrid beacon.
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 (see EPG 902.18.3).
Standard. If a Warning Beacon is used to supplement the advance warning sign, it shall be programmed to flash only when the emergency-vehicle hybrid beacon is not in the dark mode.
902.14.3 Operation of Emergency-Vehicle Hybrid Beacons (MUTCD Section 4N.03)
Standard. 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 (see Figure 902.14.2). 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.
Guidance. 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 in accordance with the provisions in EPG 902.6.17.
Guidance. A yellow change interval should have a minimum duration of 3 seconds and a maximum duration of 6 seconds (see EPG 902.6.17). 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.
Guidance. An emergency-vehicle hybrid beacon that is located 200 feet or less from an active grade crossing should be preempted in accordance with the applicable provisions in EPG 902.6.19 and EPG 913.4.9.
Standard. If an emergency-vehicle hybrid beacon is placed into a flashing mode by a conflict monitor (malfunction management unit) or by a manual switch, the emergency-vehicle hybrid beacon faces shall display flashing yellow signal indications to each approach of the major street.