"Adaptive Traffic Control Systems in the United States"

Adaptive traffic control technology holds great promise for reducing congestion on U.S. arterial roadways; however, there are only a handful of adaptive systems in operation in the U.S. Why is this? And why does the U.S. lag behind many other countries in the use of adaptive technologies? A survey of agencies that have implemented adaptive traffic control systems was conducted in an effort to gain a greater understanding of why use of adaptive technology is limited in the U.S.