This paper presents the evaluation results on operational and safety performance of group-based signal control, based on a field test undertaken inJapan recently. Starting response time (SRT), start-up lost time (SULT), clearance lost time (CLT), saturation flow rate (SFR), and approach delay (AD) are selected to represent operational performance. Certain occurrencefrequencies and rates of stop-line crossing during amber (SCA) and red-light-running (RLR) act as the measures to safety performance during intergreen intervals. The results from the before-and-after analyses supported that the group-based control itself generally didn't significantly affect SRT, SULT, CLT, and SFR, while remarkably improved AD. Meanwhile, it substantially decreased SCA and RLR at the exclusive through and right-turn lanes. It reveals that both operational and safety benefits might be expected by applying such a policy.
Abstract