The Highways Agency today launched a technology trial between junctions 28 and 27 on the M25 to reduce congestion on what is one of the busiest sections of the London Orbital.

The trial aims to control the flow of the 130,000 vehicles that use this stretch of motorway each day.

It involves deployment of congestion monitoring equipment used to monitoring traffic flow between the two junctions.

When a build up of traffic is detected an advisory speed limit of 50mph is automatically set on mobile roadside signs.

By influencing driver behaviour the Highways Agency hopes to control traffic flow before congestion occurs.