Taking Control: The M25 Orbital Motorway That Encircles London Is Infamous For Its Tailbacks That Can Often Snarl Up Several of Its 30 Junctions

This article argues that the time between technology becoming available and deployed needs to be shorter. It describes studies recently completed in the U.K., including an evaluation of the M25 Controlled Motorway, that have increased the amount of knowledge available to the Highways Agency on the potential of variable speed limits to control traffic. It suggests that knowledge acquired from projects such as Controlled Motorway, Active Traffic Management, and the use of high occupancy vehicle lanes, play a critical role in implementing new traffic management schemes efficiently and cost effectively. A detailed description of the Controlled Motorway system is included in the article.