Dynamic choice of geographical area.

Method developed to select an analysis area from a bigger transport model.

Abstract

Extensive transport models give lengthy calculation times. In order to reduce calculation times, a tool to cut out the influence area from a complete strategic transport model is developed. A Part Area Model (PAM) has new geographical definitions compared to the original transport model, but should give the exact same results. The scope of this paper introduces a new method to deal with superfluously long calculation times in transport models.

Most of the more fundamental transport infrastructure decisions are supported by transport model analysis. Regional transport models have been established for five regional areas in Norway. A joint demand model is estimated for the country, but during the calibration work minor regional adjustments were made to the parameters. Even if there were defined regional areas for the transport models to limit the calculation time, the most extensive model still holds about 6000 zones. This gives unsuitably long calculation times. Efforts have also been made to make the most of the dual-core technology, but the calculation times still need to be reduced further.

PAMs calculate the transport demand for fewer zones, the trip destinations and modal split for fewer origin-destination pairs, and contains a smaller transport network. This gives shorter calculation times, both in the network analysis phase and for each of the matrix calculations and adaptation.