Infrastructure-guided Optimal Spacing for Vehicles Approaching Intersections

Stopping at a red light at intersections is one of the main contributors to travel time delays in urban traffic. Drivers often stop as close as possible to their lead vehicle, which may cause additional time delay because they should wait before accelerating to secure a safe distance. In this paper, we present an infrastructure-based optimal spacing system that guides vehicles to maintain the optimal spacing when coming to a stop. To achieve this, we formulate an optimization problem to compute the optimal spacing between vehicles such that all vehicles can enter the intersection as soon as possible when the light turns green. To solve the problem efficiently, we decompose it into sub-problems involving only two vehicles and sequentially solve them. We validate through simulations that our approach effectively reduces travel time delay.