The impact of adverse weather conditions on traffic costs, environmental pollution and the operation of intersections with traffic signals

Living in large cities is prone to adverse environmental impacts including air pollution. Increased vehicle traffic generates congestion as some road infrastructure such as intersections, including signalised ones, have limited capacity. When congestion exceeds capacity, vehicle queues occur and their presence increases delays and generates more harmful exhaust fumes. Travel costs also increase. Studies show that adverse weather conditions negatively affect drivers’ behaviour, who become more cautious and slower to exit intersections during the green signal. Such behaviour further reduces lane capacity, increasing congestion relative to similar level of demand flow on days with favourable weather (sunny and cloudy days, no rain). The paper will demonstrate the impact of weather conditions on lane capacity and traffic performance on signalised through lanes. Worse traffic performance on days with prolonged rainfall or snowfall contributes to increased travel costs and air pollution, as will also be demonstrated in the paper.