Throughput Optimal Distributed Traffic Signal Control
  We propose a distributed algorithm for controlling traffic signals, allowing constraints such as periodic switching sequences of phases and minimum and maximum green time to be incorporated. Our algorithm is adapted from backpressure routing, which has been mainly applied to communication and power networks. We formally prove that our algorithm ensures global optimality as it leads to maximum network throughput even though the controller is constructed and implemented in a completely distributed manner. 
Tichakorn Wongpiromsarn, Tawit Uthaicharoenpong, Emilio Frazzoli, Yu   Wang and Danwei Wang
cs.SY