Operators of parking guidance and information (PGI) systems often have diculty in determining the best car park availability information to present to drivers in periods of high demand. This paper describes a behavioural model of parking choice incorporating drivers perceptions of waiting times at car parks based on PGI signs. This model was used to predict the inยฏuence of PGI signs on the overall performance of the trac system.
Relationships were developed for estimating the arrival rates at car parks based on trip patterns, driver characteristics, car park attributes as well as the car park availability information displayed on PGI signs. Drivers' perceptions of waiting times at car parks were assumed to be inยฏuenced by the PGI signs for observers of the signs and actual car park utilisation levels for non-observers. The model assumes that the choice of car park does not change after entering the city centre, even if conditions observed are dierent from those initially perceived.
A mathematical programme was formulated to determine the optimal display PGI sign conยฎguration to minimise queue lengths and vehicle kilometres of travel (VKT). The model was limited to o-street parking choices and illegal parking was not incorporated. A simple genetic algorithm was used to identify solutions that signiยฎcantly reduced queue lengths and VKT compared with existing practices.
These procedures were applied to an existing PGI system operating in Tama New Town near Tokyo. Signiยฎcant reductions in queue lengths and VKT were predicted using the optimisation model. This would reduce trac congestion and lead to various environmental beneยฎts.