active traffic management (atm) was launched as a pilot scheme on the m42 operating between junction 3a and 7 with mandatory variable speed limits, hard shoulder running, better driver information signs and a new incident management system. this system allows operators to open and close any lane to traffic in order to help manage congestion or an incident. since it started in 2006 journey times have decreased by 26% northbound and 9% southbound and journey time variability has decreased by 27%. due to the success of the trial this system was later extended northbound to junction 9 of the m42 (and onto the adjacent m6 to junction 5) and southbound along the m40 to junction 15 as part of the first phase of a nationwide roll out of the rebranded 'managed motorways; concept.