Motorists travelling on the M4 in Wiltshire are being warned to watch their speed as a new cable is being laid beside the motorway.
Officials from the Highways Agency have asked safety camera operators to help enforce speed limits while the work is being carried out.
The cable-laying started near Tormarton on 9 August and work is expected to last six months.
The vans will operate between junctions 16 and 18 when lane one is closed.
A spokesman for the safety camera partnership said the temporary speed limits through the roadworks will be enforced to protect the travelling public and the workforce.
The work involves digging a trench in the verge to lay the fibre-optic cable which will allow the latest traffic monitoring and driver information equipment to be installed.