PLANS to finally ease congestion on the Dartford Crossing are moving closer.

Firms are being sought to help deliver a £75m programme of improvements to the M25, of which up to £25m could be assigned to the planned free-flow charging system on the crossing.

It is hoped the scheme will reduce chronic congestion on the bridge at peak times.

The four-year plan will demolish existing toll booths, build new signaling gantries and realign carriageways.

The Highways Agency released a prior information notice last week intended to give potential suppliers a heads up about future work.

The agency acted on behalf of M25 managers Connect Plus in seeking companies capable of carrying out the extensive civil and technology works required.

It is being considered whether to split these elements or bundle the job into one contract.

The contract would include all kerbing, drainage, services diversions, lighting, fences and gates and traffic management on the M25.

Technology works include installing signs and signalling, vehicle height and width sensors, new traffic signals and road barrier systems, ramp metering and CCTV.

Connect Plus is holding a suppliers day on September 10 to detail plans for the Dartford Crossing improvements works.

A Highways Agency spokesperson said: "The Government recognises the importance of the Dartford Crossing as a vital transport link for the national and South East economies and has made clear that improvements at the crossing are an important priority 

"As part of these improvements, the Highways Agency is delivering a free-flow charging arrangement at the crossing using newer technology and road layout changes to allow the safe operation of the crossing while removing the need for drivers to stop at a barrier.

"We are on course to deliver these improvements by October 2014."