Assessment of Three Simulation Models for Diamond Interchange Analysis

Abstract

The performance of three traffic analysis tools: CORSIM, SIMTRAFFIC, and SYNCHRO was investigated for application to diamond interchanges. Actuated signal operation was implemented for different ramp spacings and traffic patterns. The performance differences were discussed for three performance measures: Cycle length, average delay, and total stops. Our research showed that the two microscopic models ~CORSIM and SIMTRAFFIC! produced similar performance, but the macroscopic program SYNCHRO provided different performance trends. It was found that SYNCHRO 4 and SIMTRAFFIC produced different phase splits for the same input data. Therefore, there is a possibility that estimated delay ~or stops! performance could vary depending on the model selected. Our results also indicate that SYNCHRO 4apparently does not reflect some progression effects properly, thus the application of SYNCHRO 4for diamond interchanges should be used with caution. Either SIMTRAFFIC or CORSIM used in conjunction with hardware-in-the-loop simulation should be used for analysis of actuated diamond interchanges. It was also found that SIMTRAFFIC tended to model queue spillback conditions more restrictively at the upstream intersection than did CORSIM or SYNCHRO.