Calibrating truck characteristics into traffic microsimulation

Abstract

Current practice in microsimulation model calibration is focused almost exclusively on adjusting parameters of driving behaviour (car-following and lane-changing) logic. Often, default parameter values are used for the vehicle performance logic. Where significant differences exist between the default vehicle performance characteristics and those of the local traffic, results from microsimulation analyses can be misleading, especially for networks with reasonable truck traffic. This paper presents an approach for incorporating the unique operating characteristics of the local truck fleet into the calibration process of microsimulation models. In particular, the desired acceleration and deceleration functions for trucks are treated as unknowns that must be estimated as part of the model calibration. The methodology is general and is implemented on a test bed using the VISSIM traffic microsimulation software to demonstrate its applicability. Results of the implementation highlight the need for, and the potential benefits of, calibrating both the vehicle performance and the driver behaviour parameters.