Improving Bus Ride Comfort Using GLOSA-Based Dynamic Speed Optimisation

Public transport (PT) is one of the key elements of a sustainable transport system. Improving its quality is among several measures cities are designing to raise the modal share of PT. Ride comfort is one of the key components defining the quality. In this article, we demonstrate how the comfort can be improved if buses use a Green Light Optimal Speed Advisory (GLOSA) driver assistance system. It allows a driver to adjust speed of the bus as so that it can arrive at the intersection when the light is green. It increases comfort of the passengers, reduces fuel consumption and tailpipe emissions of the bus. We use a multi segment GLOSA, i.e., several lights in a sequence on route of a bus are taken into account in order to calculate speed advice. Such approach is useful if busways are separated from traffic. The speed optimisation method is based on a genetic algorithm. In addition, performance evaluation of a single-segment GLOSA for bus operations in mixed traffic is also evaluated. Using computational experiments we demonstrate that when compared with conventional driving, where speed is not planned, the use of GLOSA results in significant improvement in ride smoothness.