The calibration of transport microsimulation models to represent base year conditions remains a difficult and onerous task. Such complexity of meeting the calibration requirements is further enhanced with the introduction of route choice whereby weight cost factors influence the attractiveness of the numerous paths. This has been identified as an issue in town centre and central business district studies where an extensive local road network is seldom travelled. The VISSIM COM interface allows for a direct two way communication between the simulation software and external programmes, such as Microsoft Excel. This allows for a cyclical motion of simulation, assessment and adjustment of the programme parameters, such as weight costs applied to generalised cost equations. Maunsell has developed a programme using Microsoft Excel Visual Basic for Applications (VBA) to adjust the unit cost parameters and improve the calibration process of microsimulation modelling. The programme utilises the COM interface to influence the route choices of vehicles until calibration parameters are achieved. This allows for an improved representation of base year generalised cost parameters and better reflects the trip making patterns currently undertaken by motorists. (a) For the covering entry of this conference, please see IRRD abstract no. E216410.
Samenvatting