Traffic signals and the design of arterial facilities affect us daily as we travel to and from work, school, shopping and recreational facilities. There are an estimated 272,000 traffic signals in the United States and each has a profound impact on how safety and efficiently we share the space of intersections as we travel to our destinations.  Proper signal management can reduce congestion and save time for commercial and emergency vehicles, buses and the public.  Installing signals in the wrong locations can lead to unnecessary delay and decreased safety.