Highway bosses have released images today of a new safety system to identify heavy vehicles at the Dartford Crossing after the removal of the toll booths.

The changes will identify and manage overheight vehicles and dangerous loads before they enter the tunnel – a job previously carried out at the barriers.

Rules outlining what substances can be taken through tunnels may require some vehicles to be provided with an escort while some may be prohibited altogether.

In addition, both bores are slightly different sizes having opened nearly 20 years apart with separate height restrictions.

The system has been tested over the past six months at a disused airfield using vehicles from a local haulage firm.

Its introduction comes as part of wider changes, which include signage on the approach to the crossing, to give HGV drivers enough warning to get in the correct lane.

Since Dart Charge was introduced in November, journeys on both the Essex and Kent side of the crossing have been quicker according to the Highways Agency.

Highways Agency project director Nigel Gray said: “With Dart Charge, drivers no longer stop at a barrier to pay the crossing charge, speeding up journeys and reducing congestion.

"But the barriers are also the point at which we have identified and managed dangerous loads and oversized vehicles – so now we need a new approach.

"This system has been extensively tested and will be able to do the job effectively, and without requiring every driver to stop.

"It is a big part of fully realising the benefits that Dart Charge is already bringing."

Construction of new traffic signals and barriers on the northbound carriageway will begin later this month and is due to be completed in April.

Guidance for haulage drivers is available on the Highways Agency website.