The positive impacts of designing transition between traffic signal plans considering social cost

Traffic congestion generates social costs associated with additional travel time, fuel consumption and gas emissions, among others externalities. The design and implementation of policies and strategies for improving the efficiency of transport systems and mobility in cities may lead to a potential reduction of such externalities. Traffic signals plans are defined as the process of switching from one timing plan to another. The optimal implementation of the transition between signal plans is a strategy to improve the performance of signal systems. However, despite their importance, few studies have addressed it from a social approach using mathematical modelling and optimisation techniques. The purpose of this article is to evaluate the impacts of implementing the transition between signal timing plans designed from a mathematical model that minimises social costs (delays, air pollution emissions and fuel consumption). Impacts are evaluated for an arterial corridor traffic lights intersections in the city of Santander (Spain). The performance for reducing social costs of the proposed model was compared with other traditional methods. Results show that the proposed model overperforms the traditional approaches, reducing the level of externalities and social costs. Consideration of social costs when designing a transition between signal plans is a good tool to be considered by traffic planners.