Abstract
An important factor in the design of traffic signals and intersection capacity analysis is the inclusion of a factor to allow for the fact that turning vehicles, and heavy vehicles, may take a longer time to traverse the intersection than a passenger car travelling straight through the intersection. This factor is typically taken into account by expressing the influence of these vehicles in terms of a "through car equivalent". This paper reports the results of a study which investigated the validity of these estimates for current traffic, based upon surveys carried out in Melbourne.