Evaluation of bus lanes

This study relates to the evaluation of bus lanes. It has concentrated on deriving methods for predicting the principal effect of bus lanes, which is on the journey times of priority and non-priority vehicles, although all impacts are considered. This was undertaken by initially collecting data at 22 with-flow and 3 contra-flow bus lanes throughout the UK, covering parameters such as traffic flows and journey times for priority and non-priority vehicles. Such measurements allowed estimates to be made of the maximum journey time (and associated cost) savings for priority vehicles due to the bus lane. However, the prediction of the effects of the bus lanes on non-priority traffic required an assessment to be made of the suitability of three computer-based traffic models, TRAFFICQ, CONTRAM and BLAMP, and their application to all or a sample of the study sites. This application involved initial 'calibration' of the models to reflect existing traffic conditions at each site followed by further modelling with the bus lane(s) removed to obtain predictions of 'without' bus lane journey times. These results have enabled predicted economic benefits/disbenefits of each bus lane to be determined. A step-by-step procedure for evaluating bus lanes, using either modelling or non-modelling techniques as appropriate, has also been developed and is described in the report. This procedure is illustrated using data from two bus lanes recently introduced in London, where 'before-and-after' surveys were carried out which have also allowed elements of the evaluation procedure to be validated. For other studies undertaken as part of the review of bus priority measures see Contractor Reports Nos 88 and 89 (IRRD 816384 and 816385 respectively).