  Today's fixed-cycle traffic signaling is highly suboptimal and aggravates
traffic congestion and waste of energy in urban areas. In addition, it offers
no quality-of-service guarantee and makes travel time prediction extremely
hard. While existing traffic light control research primarily focuses on
improving the average wait time of cars, we study in this paper how traffic
light scheduling affects the worst-case wait time. In particular, we derive the
time a car spends at an intersection in the best-case and the worst-case,
respectively. Using the theoretical results, we propose a simple but effective
controller and run simulation to verify its performance. The result shows that
it works much better than fixed-cycle controllers in both light and heavy
traffic scenarios.
