M. Azam, S.A. Hassan, O.C. Puan
Heterogeneous traffic conditions are characterized by a mix of vehicles with varying static and dynamic characteristics. Modelling of such traffic conditions is a challenging task due to various factors including; involvement of smaller vehicles and their unpredictable longitudinal and lateral driving behaviour, position of vehicle irrespective of lane, and seepage of two-wheelers at a junction. However, modification of certain parameters in simulation packages helps to reflect such complex driving behaviour. This modification of parameter values to match the simulated and actual field conditions is known as calibration. In literature, several calibration methodologies have been adopted to simulate different traffic conditions. This paper reviews the studies discussing VISSIM-based calibration methodologies for heterogeneous traffic conditions. Various geometric conditions, data types required for a simulation study, data collection techniques and employed calibration procedures from the previous studies are explored in this paper. Significant efforts with prior focus on calibration of heterogeneous traffic are pointed out. Moreover, several approaches to identify and optimize the calibration parameters for VISSIM microsimulation package are also discussed. Text analysis of the studies conducted by VOSviewer 1.6.18 showed that sensitivity analysis and genetic algorithm are the most frequently adopted methods for the selection and optimization of calibration parameters respectively. Despite, considerable efforts have been made to reflect the characteristics of heterogeneous traffic conditions, there is still significant gap to simulate certain characteristics of non-lane based heterogeneous traffic conditions. There is a need of researches involving various site and traffic characteristics pertaining to traffic in developing countries which will help to identify the optimal driving behaviour parameter sets for any desired traffic and site conditions in developing countries.
Keywords: calibration; driving behaviour; heterogeneous traffic; simulation model; VISSIM