Citation

Paksarsawan S, May AD, Montgomery FO. Traffic Eng. Control 1995; 36(10): 551-558.

Affiliation

JMP Consultants Ltd, Leeds, UK

Copyright

(Copyright © 1995, Hemming Group)

DOI

unavailable

PMID

unavailable

Abstract

Bangkok, the capital of Thailand, is one of the fastest-growing cities in the world, both in terms of economy and car ownership levels. Therefore, traffic congestion is rapidly increasing. The traffic network is characterised by large signalised junctions, with up to 20 entry lanes, coupled with long signal cycle times of up to 7-10 minutes during the peak periods. One of the main traffic problems is blocking of upstream junctions. To analyse the queueing behaviour at junctions, TRAF-NETSIM version 3.0 has been used. It is, however, beyond the capability of standard TRAF-NETSIM to model the tendency of vehicles in Bangkok to pass through gaps and to swing around the back of traffic blocking their paths at junctions. To enable this behaviour to be modelled, the program was modified extensively. Tests of these modifications on a hypothetical network showed that the modified TRAF-NETSIM generally worked as expected. Finally, the standard and modified TRAF-NETSIM were applied to a model of the Bangkapi area of Bangkok. The outputs in terms of average speeds, average queues and maximum queues, were investigated. It is shown that (i) the modified TRAF-NETSIM provides outputs closer to the observed data than outputs from the standard TRAF-NETSIM; and (ii) simulation of the unequal cycle times and irregular stages occurring in practice requires further research. The study has demonstrated the need to adapt'off-the shelf' packages to take account of local network characteristics and local driver behaviour, if meaningful results are to be derived.