“Road Traffic Control: Past, Present and Future”
Daily traffic congestion on urban road and freeway networks around the world continues to increase, with detrimental effects on travel times, traffic safety, fuel consumption and environmental pollution. The annual cost of traffic congestion on European roads is estimated to 100 b€ or 1% of the GDP. Traffic congestion is only partly due to high demand, since the appearing congestion degrades the infrastructure capacity essentially at the only times it is actually needed, i.e. during the daily peak periods. Traffic control measures, if properly designed and deployed, may lead to mitigation of congestion and its consequences. The presentation will outline the related traffic control problems and methods, with a focus on practicable results. More specifically, the areas of signal control in urban networks, route guidance, freeway ramp metering and variable speed limit control will be addressed, along with the presentation of some selected field results. In addition, current and future prospects, emerging developments and needs in relation to VACS (vehicle automation and communication systems) and their implications for traffic control will also be addressed. The presentation will conclude with a more futuristic new traffic paradigm for fully automated and connected vehicles driving without lanes and employing vehicle nudging in all directions.