Calibration and validation of a micro-simulation model for a local arterial in Cape Town

Abstract

Paper presented at the 31st Annual Southern African Transport Conference 9-12 July 2012 "Getting Southern Africa to Work", CSIR International Convention Centre, Pretoria, South Africa.

Traffic simulation models have been widely used to study traffic operations and systems impacts because simulation is safer, less expensive and faster than field implementation and testing. Their use has also increased dramatically in recent years due to their flexibility and ability to visualise simulations. Whilst the models are useful to the profession, they must be calibrated and validated before they can be used to provide realistic results. However, the transportation profession has not yet established any formally accepted or consistent guidelines for the calibration of these models. In practice, many model based studies are conducted under default parameter values, limited field observations or best-guessed values. This is mainly due to the difficulties in collecting field data for these variables, the complexity of evaluating key parameters and the ranges of their values due to their interaction and the lack of a readily available procedure for model calibration. This paper provides a summary of some of the published methods of calibration to provide a contextual background to the identification of the key parameters and the calibration of a microscopic simulation model of a local arterial in Cape Town.