Traffic Signal Warrants
Traffic signals should not be considered for installation unless one or more of the following warrants are met:
Warrant 1 – Eight-Hour Vehicular Volume
This warrant is intended for application where a large volume of intersecting traffic is the principal reason for consideration of signal installation. This warrant applies to operating conditions where the traffic volume on a major street is so heavy that traffic on a minor intersecting street suffers excessive delay or hazard in entering a major street. Minimum volumes are given for each of any 8 hours of an average day.
Warrant 2 – Four-Hour Vehicular Volume
This warrant is satisfied when each of any 4 hours of an average day are above a certain volume combination for the major and minor streets.
Warrant 3 – Peak Hour Vehicular Volumes
This warrant is intended for application when traffic conditions are such that for a minimum of one hour of an average day, minor street traffic suffers undue traffic delay in entering or crossing the major street.
Warrant 4 – Pedestrian Volume
This warrant states that a traffic signal may be installed where the pedestrian volume crossing the major street at a location during an average day is:
- 100 or more per hour for each of any 4 hours or
- 190 or more during any one hour
And there shall be less than 60 adequate gaps per hour in the traffic stream.
Warrant 5 – School Crossing
This warrant states a traffic signal may be installed at an established school crossing where the number of adequate gaps in the traffic stream is less than one per minute in the period when children are using the crossing and there are a minimum of 20 students crossing during the highest crossing hour.
Warrant 6 – Coordinated Signal System
This warrant specifies conditions where a traffic signal may be warranted in order to maintain proper platooning of vehicles.
Warrant 7 – Crash Experience
This warrant is satisfied when an adequate trial of less restrictive remedies has failed to reduce the crash frequency of five or more reported crashes of types susceptible to correction by traffic signal control and minimum vehicle and pedestrian volumes are present.
Warrant 8 – Roadway Network
This warrant specifies conditions where a traffic signal may be justified to encourage concentration and organization of traffic flow.
Warrant 9 – Intersection Near a Grade Crossing
This warrant is intended for use at a location where none of the conditions described in the other eight traffic signal warrants are met, but the proximity to the intersection of a grade crossing on an intersection approach controlled by a STOP or YIELD sign is the principal reason to consider installing a traffic control signal.
For further information on the nine traffic signal warrants, please see the Manual on Uniform Traffic Control Devices.