Evaluation of Variable Maximum Green Time to Improve Rural Traffic Signal Operations

Abstract

Rural agencies frequently struggle to provide reasonable traffic signal operations because they lack the financial resources and traffic expertise common to larger cities. More advanced traffic signal controllers have many features that might help. One such feature is variable maximum green time (VMGT), also called the dynamic maximum, which allows the controller to continually adjust the maximum green in response to changes in traffic demand. Rural traffic signal operations are compared, given optimized timing with rural traffic signal control operations using a generic set of VMGT parameters. The research method included the use of software-in-the-loop simulation with VISSIM as the traffic simulation model and Econolite ASC/3 traffic controller software. Results from one high-volume and one low-volume site indicate that compared with optimized timings, a generic set of VMGT parameters can provide equivalent throughput, nearly equivalent average intersection delays, reasonable cycle lengths, and a more equal distribution of delay among approaches and movements.