Control of connected and autonomous vehicles

Abstract

With an average increase of 36 vehicles per day, the Maltese road network is reaching saturation. It is not just the sheer number of vehicles that is creating the problem of traffic congestion on the road network but the dependency that we as a society have on them. Traffic wastes time, money, pollutes the air as well as increases stress and noise levels. Thus, it is in everyone’s interest that this issue is mitigated or even eliminated. A significant breakthrough may be achieved through the development of Connected and Autonomous Vehicles (CAVs). The aim of this study is to review and implement control algorithms for CAVs, and to quantify their benefits through calibrated simulations at a local signalized urban junction at different CAV market penetration rates. In this project, the Rue D’Argens and Sliema road junction is considered. However, the methodologies used in this project can be applied to any signalised junction. As there are multiple approaches towards the use of CAVs to mitigate traffic congestion, it was decided to implement four traffic management systems and compare the performance benefits they each have on the junction. These approaches all collect the required data from the CAVs approaching the junction, however one approach use this data to control the traffic light timings, another controls the vehicle trajectories while the final two take control of both. From the results obtained, it can be shown that statistical improvement could be made to the traffic flow at the junction with CAV market penetrations as low as 20%. It was also concluded that the best performing approach is that of grouping vehicles into platoons while simultaneously making changes to the traffic light timings such that these platoons could pass uninterrupted through the junction. This method improved traffic flow through the junction by an average of 360%. However, at low CAV penetration rates, the majority of these benefits can be gained by using the data obtained by CAVs to only control the traffic lights and distribute the green time according to the demand of each junction link.