Urban traffic control is a well-defined and practised art. Nevertheless, there are technologies here and on the horizon with the potential to revolutionise how we do things. By Gavin Jackman and Andrew Kirkham, TRL, and Jason Barnes. Distributed monitoring and control of urban traffic networks and flows is nothing new. PC-based Urban Traffic Control (UTC) is now well established and operating in many locations around the world. However, it is worth considering the effects of the huge growth in the use of sm