Congestion-busting signs tested on motorway

Electronic signs that tell drivers how long it will take to complete a motorway journey are being road-tested in England.

The congestion-busting sign system, which is being trialled by the Highways Agency, uses historical traffic data plus information from automatic number plate recognition cameras on the motorways to inform drivers of the expected travel time to specific junctions on the motorway, said Steve Crosthwaite, head of the National Traffic Control Centre in Birmingham, which is running the trial.

He told silicon.com: "By using that data and the data coming in real time, the computer can calculate the time it will take for a journey and at the moment the feedback we are getting is that we are getting it right. The feedback has been very good indeed."

Travel times are recalculated every five minutes and the signs updated accordingly. If delays on the motorway climb too high the sign switches from travel time to showing the estimated delay.

By telling motorists of conditions ahead in real-time the idea is they will be able to change their route when there are problems and so cut congestion. If successful the system could see nationwide roll out - potentially on all motorways in the next year.

The trial will run until early September. It covers 160 miles of two of central England's busiest motorways, the M6 and M5. More than 200,000 vehicles per day travel on these routes.

The system uses data from a network of electronic monitoring equipment including 3,750 on-road sensors and 700 CCTV cameras. Other information to help build traffic-flow models comes from police forces, local highway authorities, contractors, leisure and entertainment venues, and weather centres.

And the database of historical data it draws on is one of the biggest Windows-based Oracle databases in the world, with a terabyte of data added every month.

Travel and delay times may be replaced during major incidents by safety and diversion messages but it is expected that the journey-time messages will be visible about 80 per cent of the time.