Drivers are once again being forced to wait for a barrier-free Dartford Crossing after the Highways Agency announced the scheme has been delayed by a month.

New free-flow tolls, allowing motorists to use the crossing without having to stop at barriers and pay, were supposed to be introduced on October 28.

However this has been pushed back by up to four weeks.

The new technology - known as 'Dart Charge' - will allow motorists to pay through a variety of methods including telephone, text message, online and at retail outlets, giving drivers greater flexibility in how and when they pay the charge.

Following the delay, the Highways Agency has incurred the wrath of Freight Transport Association (FTA), who say it will result in "unacceptable" additional costs.

Malcolm Bingham, FTA's head of road network management policy said: "It is disappointing news that the free-flow tolling at Dartford is now to be delayed - the costs of this hold-up are unacceptable to the freight industry.

"FTA has been asking for a long time for this system to be introduced as this is the appropriate way forward in order to reduce a good deal of administration costs for the freight industry in dealing with tolls, charges and queues at the crossing.

"FTA has previously expressed support for the free-flow system, saying that it would be ‘good news for the freight industry’."

David Searles, a driver with Swanway Haulage based in Garden Place, Dartford added: "It’s not a surprise really, we all expected it.

"As drivers we already try to avoid the tunnel because it’s too expensive - we divert to the Blackwall tunnel but then that gets backed up and that’s why it’s always congested.

"It’s only going to get worse but if we don’t have a choice, we don’t have a choice."

In fact, full benefits of the scheme will only be delivered by the end of April next year, when all changes to the road layout are complete.

But the Highways Agency says the timetable will ensure drivers have enough notice to prepare for the changes and that the system is fully tested before it is introduced.

Highways Agency project leader Nigel Gray said: "Dart Charge is a massive change for drivers using the Dartford Crossing and it’s only right that it is thoroughly tested before being introduced.

"We want to help drivers to be ready for the improvements we’re making at the crossing.

"That’s why we are saying today that Dart Charge will start during late November.

"We can reassure drivers that we’ll give them plenty of notice before the changes are introduced.

"They will have considerable time to sign up for a pre-pay account, which for most will be the easiest and cheapest way to pay the charge - with discounts of up to a third on every crossing.

"Until Dart Charge goes live, the current payment arrangements for the road user charge at the crossing will continue - cash at the Crossing, through a DART-Tag or local residents account.”