Assigned to TRANS                                                                                                                         FOR COMMITTEE

ARIZONA STATE SENATE

Forty-seventh Legislature, Second Regular Session

FACT SHEET FOR S.B. 1001

yellow signal duration

Purpose

            Requires the steady yellow signal on all traffic control devices to be at least four seconds.  Allows city councils to waive the requirement, as necessary.

Background

            Arizona law currently requires local governments to place and maintain traffic control devices as the local jurisdiction deems necessary and all traffic control devices erected must conform to the Manual on Uniform Traffic Control Devices (MUTCD) published by the Federal Highway Administration.  The MUTCD recommends the yellow change interval have a range of approximately three to six seconds, with longer intervals generally appropriate where traffic speeds are higher.  The methodology used to determine the duration of the yellow interval is intended to provide adequate time for a reasonable driver to traverse the stopping distance.

            According to the U.S. Department of Transportation Federal Highway Administration, each year, more than 1.8 million intersection crashes occur.  Of those crashes in 2003, about 206,000 were due to red light running, which resulted in 934 deaths and approximately 176,000 injuries.

            The Arizona Department of Transportation (ADOT) has stated that red light running crashes have become an increasing concern for the traffic safety community.  A 2004 Phoenix Traffic Collision Summary compiled by the Street Transportation Department revealed that 20 people were killed and 2,740 people were injured in red light running collisions.

            The Texas Transportation Institute conducted a study in which 181 intersections were examined over a three-year period to investigate solutions for red light running.  The study found that when the duration of the yellow signal is one second shorter than the standard the Institute of Transportation Engineers (ITE) timing formula recommends as a minimum, red light violations increase 110 percent.  In contrast, adding an additional second to the ITE minimum yellow duration recommendation yielded a 53 percent reduction in violations.  According to that same study, yellow signal timing proved most effective in reducing crashes with the extra second yielding a 40 percent collision reduction.  ITE’s study also found that the majority of red light camera tickets are issued within the first second a light is red.  The average ticket is issued when the light has been red for half a second or less.

Although there is no anticipated fiscal impact to the state General Fund, the City of Phoenix Street Transportation Department estimates increasing the yellow signal duration will have a significant but currently undetermined fiscal impact at the local level and require at least two years to implement.  Signal system specialists will be required to develop new timing schemes from the Traffic Management Center, and signal technicians will be required to implement the new plans at over 500 intersections with posted speed limits lower than 40 miles per hour.

Provisions

1. Requires local jurisdictions to make the steady yellow signal on all traffic control devices at least four seconds on or before January 1, 2007.

2. Allows a city council to waive the requirement for an intersection by majority vote if good cause is found for the waiver.

3. Makes conforming changes.

4. Provides for a general effective date.

Prepared by Senate Research

January 20, 2006

DG/RD/jas