M25 variable speed limit work begins in Surrey
Work has begun on introducing variable speed limits on a section of the M25 in Surrey.
Overhead gantries which will carry the variable speed limit signs are being installed between junction seven for the M23 and junction eight for Reigate.
The work will link the existing variable limits between junctions eight and 16 with those being installed between five and seven.
The variable limits are expected to be in force by December.
Keep traffic moving
"The idea is to smooth out the traffic flow so you don't get heavy braking and risk of collisions, which then cause a further delay," said Highways Agency spokesman Martyn Lines.
He said there would be lane closures at night while the system was being installed.
It uses sensors in the road surface to detect the speed, volume and flow of vehicles, then calculate the optimum speed to keep vehicles moving and reduce stop-start traffic.
A £250m scheme is under way to widen a 15-mile (24km) stretch of the M25 through Kent and Surrey between Sevenoaks and Redhill.