A system-optimum approach for bus lanes dynamically activated by road traffic

In this paper, we investigate the performance of a bus lane that is (de)activated under specific road traffic and public transport conditions. More specific, the VISSIM microscopic simulation software along with VisVAP and EnViVer add-on modules were employed to represent the operation of a bus lane with intermittent use by cars in a highly congested arterial. We modelled various scenarios to determine the level of traffic volumes and bus service frequencies for which such bus lane concept would be effective. Empirical findings showed that when peak hour volumes range between 1000 and 2000 vehicles, the mixing of cars and buses on bus lanes may lead to a) serious reductions of vehicles’ queue lengths, b) significant decreases of greenhouse gas and air pollutant emissions derived from traffic flow and speed profile improvements and c) financial viability of the experiment. The joint use of bus lanes at 2000 vehicles per peak hour was highlighted as the most financially viable scenario. On the other hand, delays were comparatively increased due to the lower speed of cars which were moving onto the bus lane. Finally, our bus lane concept was not performed well under bus headways shorter than 2 min.