Citation

Noble DE. ITE J. 2020; 90(3): 28-31.

Copyright

(Copyright © 2020, Institute of Transportation Engineers)

DOI

unavailable

PMID

unavailable

Abstract

ITE has concluded a years-long effort to issue guidance on yellow change and red clearance intervals for signalized intersections. The final version of the Recommended Practice Guidelines for Determining Traffic Signal Change and Clearance Intervals (RP-040B) has been adopted by the ITE International Board of Direction and is now available. This article provides an overview of that report, which describes the recommended methods to calculate traffic signal change and clearance intervals. The calculation methodology in the report is based on the extended kinematic equation and is shown in both U.S. and metric units. The report provides guidance for applying the methodology and for selecting input values for both through and turning movements at signalized intersections. Input values include perception-reaction time, approach speed, deceleration rate, approach grade, intersection width, vehicle length, and conflicting movement start-up delay. The report notes application techniques for wide intersections and bicycle traffic. The application of measures of effectiveness and recommendations for monitoring and evaluation close the report.

Language: en

Keywords

Traffic signals; Guidelines; Clearance interval (Traffic signal cycle); Change interval (Traffic signal cycle); Guidelines for Determining Traffic Signal Change and Clearance Intervals (RP-040B); Institute of Transportation Engineers