Employing Cyber-Physical Systems: Dynamic Traffic Light Control at Road Intersections

Traffic lights (TLs) are used to control traffic at road intersections. Typically, the TL control mechanism on the road operates according to a fixed periodic schedule to change the light (red/yellow/green). A different schedule may be employed at late night or early morning hours. Such fixed light control does not react to changing traffic conditions, and is unaware of (unresponsive to) congestion. In this paper, we propose a novel framework dynamic TL control (DTLC) at road intersections. DTLC relies on a sensor network to collect traffic data and includes novel protocols to handle congestion and facilitate more efficient traffic flow. The proposed low-overhead algorithms are practical to employ in live traffic flow scenarios. Through analysis and simulations, we demonstrate the benefits of DTLC in optimizing traffic flow metrics, such as traffic throughput, vehicle waiting time, and waiting line length. This paper is a step toward employing smart TLs, which are part of the future envisioned “Smart City.”