Operational and Safety Effects of a Reduced Cycle Length Strategy

Abstract

Designing to operate at a minimum cycle length that is practically feasible, referred to as “reduced cycle length (RCL) strategy” in this paper, may decrease intersection delay, queue length and the total number of stops. It could also improve safety (decrease the number of crashes) and lead to a more organized movement of system users. The objective of this research paper is (1) to evaluate the effect of RCL strategy on operational performance measures through the comparison of before-after field data; (2) to compare the number of crashes before and after the implementation of RCL strategy; and (3) to examine the effect of RCL strategy over time. Monroe Rd and Wendover Rd in the city of Charlotte, North Carolina were selected to study the effect of RCL strategy. Selected signalized intersections along these corridors were re-designed to operate at a practical minimum cycle length - 120 seconds during the morning peak hour and 70 seconds (half-cycle) or 140 seconds during the evening peak hour. Findings based on the comparison of data collected before and after the implementation of RCL strategy showed a decrease in the average intersection delay, the number of stops and the maximum queue length at three out of the four selected signalized intersections. An increase in pedestrian activity and a decrease in pedestrian delay was observed at most of the selected signalized intersections. A decrease in the number of crashes was also observed after the implementation of RCL strategy. No specific trend in operational performance or safety was observed at the selected signalized intersections over time (year 2014 compared to year 2009).