N. Jayasooriya, L. Perera, S. Bandara

Pages: 39-52

Abstract
Traffic micro modelling is becoming popular day by day among researchers as well as practitioners. Both micro and macro simulations are widely used in the real world, but there are several practical issues arising when the micro modelling simulations are used for mesoscopic simulations. Further, there could be situations, where static assignment may lead to complex conditions where road geometry changes from partial lane closures to fully lane closures, one-way arrangements, changes in lane widths and change in road surface texture. Therefore, it is important to consider the dynamic assignments in mesoscopic modelling in practical scenarios. Nevertheless, no proper guidelines are available for calibrating such a dynamic assignment model in mesoscopic simulations, especially when using VISSIM micro simulation modelling. Hence, this study develops a set of guidelines to be adhered to when a dynamic assignment is applied in mesoscopic modelling. From the basic steps of origin destination matrix developments, the research identifies the important criteria for successful convergence which is further developed to a dynamically calibrated model using VISSIM traffic simulations software. The developed methodology is validated using a case study conducted at a complex urban intersection cluster. GEH Statistics are used for comparison of the observed flows with model flows and 97% of the values are found to be well within the acceptable levels.
Keywords: dynamic assignment; mesoscopic simulations; VISSIM modelling; calibration