Quantitative Approach for Coordination, at Scale, of Signalized Intersection Pairs

The coordination of signalized intersections in urban cities improves both traffic operations and environmental aspects. Traffic signal coordination has a long history, where the impact of offset on delays and emissions at signalized intersections has been investigated through simulations and a limited number of experimental findings. Coordinating intersections is often warranted by specific engineering requirements and judgment. However, as a consequence, many intersections in cities remain without coordination. In this paper, we examine the potential benefits of coordinating signalized intersections at scale. Unlike previous studies, our analysis is based on aggregated anonymized probe data analysis and does not need to explicitly model traffic-oriented issues such as queue spillback and platoon dispersion. We follow a quantitative approach by considering an intersection pair, i.e. a system of two signalized intersections which can be spatially coupled. We introduce a new method for coordinating those signalized intersections. The method first evaluates the effect of different offsets on vehicle travel times and fuel consumption (or emissions). Then, it coordinates the two intersections by setting a common cycle and finding the optimal offset that minimizes fuel consumption and/or travel times. We present the analysis for several case studies from real intersections at Jakarta, Rio de Janeiro, Kolkata, and Haifa. Finally, we evaluated our method by implementing it in a real experimental study at Jakarta. We collaborated with the city to implement the optimal offset determined by the proposed method, and we compared the results before and after coordination.