Calibrating Traffic Microsimulation Model for Bahrain and Estimating Traffic Impacts of a Mall on Road Network

Abstract

Traffic simulation programs such as VISSIM are frequently used worldwide as a tool, for analyzing transportation problems, with minimum cost. Traffic simulation is an effective approach for finding out the benefits and limitations of different alternatives. Advancements in computer technology have led to the development of high-quality microscopic simulation models. The calibration of a simulation model is the main step for obtaining any representative results from the analysis. Therefore, objectives of this study include; to calibrate a microscopic simulation model using VISSIM for Bahrain and to estimate the effects of construction of a new mall using the calibrated microscopic simulation model. The study location was Avenue 27, Saar, Kingdom of Bahrain. Traffic data from two intersections of this avenue, which were in the vicinity of a new mall (El Marcado), was collected for the period before and after the construction of the mall. The road segment between the intersections had a length of 600m. The posted speed of the road is 50Km/hr. Ministry of Works provided the data for straight movement on this segment and proportion of turning movements were estimated from a dataset collected by the research team for a shorter time period in AM and PM peak hours. A microsimulation model was calibrated on the studied segment using the dataset collected by the research team. Default values for several parameters such as volume, average travel time and average travel speed were modified to replicate field conditions. The results with the modified values showed no significant discrepancy between the model simulation and the field observed values. The simulation model was run on the data provided by the ministry for the periods before and after construction of the mall. The simulation results showed a clear deterioration in traffic conditions on the overall network and more specifically for turning movements towards the mall. Increase in traffic, due to the mall, reduced Level of Service (LOS) on the intersections and doubled the queue length and delay on them. The environmental estimation method in VISSIM was not found to be effective in accurate simulation of emissions and fuel consumption.