The report details the results of a feasibility study which addresses the problem of faults at traffic signals which cause "excessive disruption" and the development of level- of- service criteria for the maintenance of traffic signals which ensure that these disruptive faults remain within acceptable limits. A literature review and a review of australian and overseas practice was undertaken. The results of these reviews were that no significant work was found on the driver behaviour at traffic signals with fault conditions. However, there was a significant body of work dealing with the economics of traffic signal maintenance, all showing the very large benefits of such a programme. In this report mathematical models for determining the fraction of signal defective so as to ensure that the incidence of "excessive" delays are below an "acceptable" limit. The report also presents mathematical models of the economics of maintenance. Using overseas data applied to the sydney metropolitan area, it is estimated that the current traffic signal maintenance programme has a benefit/ cost ratio in excess of nine. The report also discusses means of estimating the components of the mathematical models described and concludes that it is feasible to proceed to the next stage of the project, the estimation of the behavioural and economic models. (Author/publisher)
Abstract