CALIBRATION OF VISSIM MODEL FOR MULTILANE HIGHWAYS USING SPEED FLOW CURVES

Abstract

Traffic flow is a complex phenomenon that needs better understanding of basic conceptsand methods for its analysis. As a solution to practical problems, computer simulation has beenproved to be a powerful tool in replicating complex traffic systems which allows experimentation tothe basic traffic flow system. Various methods are available in literature, some of the methods usestatistical tools to verify the difference between simulated and actual outputs and some are basedon optimization which tries to minimize the error. For the present work, suitable methodology isadopted for the calibration process. Field data is collected, statistical tests are performed. For thesimulation, VISSIM microscopic simulation tool is used and data analysis is performed byconsidering individual parameters and performance measures like speed, volume and randomseed number. Statistical tests have been performed to check the sensitivity of the differentsimulation parameters. Calibration is done using trial and error method and optimization isperformed using solver function. The maximum simulated flow rate was found with default valuesas 4599 veh/hr, and with calibrated values is 5147 veh/hr which is close to the target capacity 4958veh/hr as obtained using field composition. Calibrated values of CC0 and CC1 and CC2parameters were found as most optimized values to achieve target capacity. Finally, validation ofcalibrated parameter was performed by using different section of a multilane highway.