Sensitivity test of IHCM 1997 traffic signal timings using TRANSYT program and VISSIM Free

The 1997 Indonesian Highway Capacity Manual (IHCM) is widely used to calculate signal timings for Fixed Time Signal Control (FTSC). Comparison between FTSC and Fuzzy Logic Traffic Signal Control (FLTSC) is claimed to be valid if the calculation of signal timings using the 1997 IHCM formula gives optimum fixed time settings. To determine whether the 1997 IHCM formula produces optimum signal timings, its performance was investigated by conducting sensitivity tests using the TRANSYT program. The sensitivity test results showed that the signal timings obtained from the 1997 IHCM as tested using TRANSYT program did not produce the lowest Performance Index. It was necessary to test the signal timings from both methods using an independent microscopic traffic simulation called VISSIM. The simulation results show that the FTSC using signal timings of the 1997 IHCM formula yielded less average delay of vehicles at an intersection than those resulted using optimum signal timings of TRANSYT program. Therefore, it can be concluded that the fixed time settings calculated by the 1997 IHCM formula are appropriate for comparing the FTSC results against the FLTSC results in VISSIM applications.