Congestion woes are expected to be put off for just 30 years despite plans for an £8bn crossing under the Thames, the leader of the project has admitted.

The 14-mile route which is proposed near Chalk, east of Gravesend, has been criticised by campaigners as "not being fit for purpose".

Major congestion around the Dartford Crossing has been a blight for residents in the town for decades while there are regular delays on the M25 for drivers crossing between Kent and Essex.

But despite the proposals, bosses expect current traffic around the town and at the Dartford Crossing to return in the late 2040s due to population growth and increased traffic.

Matt Palmer, executive director for the Lower Thames Crossing (LTC), has now said the development is likely to only "buy us time" and will not solve the problems indefinitely.

His comments came while appearing alongside Thames Crossing Action Group (TCAG) chairman Laura Blake on a BBC Essex radio show.

TCAG says figures used by Highways England – now known as National Highways – as part of its latest consultation on the crossing plans will still see the Dartford Crossing operating way above its designed capacity should LTC be given the go ahead.

Dartford currently manages about 180,000 crossings per day – some 45,000 higher than the 135,000 it was designed to take.

But Ms Blake said with the capacity of the LTC tunnels taking 21% of traffic away from Dartford, dropping to 14% in 2044, and traffic volumes estimated to increase by about 20% there would still be about 170,000 vehicles using Dartford every day even when LTC opens.

She added: "It will still be over capacity and very similar to what we're suffering with now. We're talking about a lot of destruction and £8.2bn of taxpayers money to pretty much leave us where we are now.

"There are other options and I think we deserve better. We've never been given adequate consultation on other options."

Mr Palmer said: "The point really is the Dartford Crossing needs relief.

"The scheme on opening will drop capacity [in both directions] at Dartford to 85% of its design so we'll get spare capacity there.

"It will be the late 2040s to today or yesterday traffic levels so it buys us time. It won't solve the problem indefinitely and we've never been saying that.

"This is one of the pieces of infrastructure we need to relieve the crossing and there will be more need for other things later and other developments.

"But this is a very good doubling of capacity east of London."

Mr Palmer added 13 million vehicles which would normally use the Dartford Crossing will use LTC every year allowing Dartford to return "back below the level it was designed for" and make a "dramatic improvement to what we experience now".

Dartford councillor Kelly Grehan (Lab) says congestion in the town is so bad and recalled how one constituent told her they'd missed being able to see their mum before she died because they had been stuck in traffic too long.

"It's massively frustrating and people feel very angry," Cllr Grehan told KentOnline.

"I went to a wedding and missed the service because it was busy. What I've found most stressful was picking the kids up from nursery and worrying about them being the last ones stuck there."

The Stone House ward member says she feels the LTC proposals "might make a bit of difference but not enough" to the jams in Dartford.

She added: "I wouldn't want LTC scrapped because anything that makes any difference is good but we're living in a dream world if we think it will sort it out. It is not a magic bullet.

"I was 11 when the Queen opened the bridge and that bought us time but it's the only big thing in my lifetime which has happened.

"It's got so bad now there's no single thing that will fix this now.

"My feeling is that when it's built, which never gets any closer, with all the building and unless there's a massive change to lifestyles, taking into account the new growth it will be no better than it is now."

Cllr Grehan says while walking or taking the bus can be an option in the town, there are days when she can "taste the pollution" in the air caused by static vehicles clogging up the town and buses simply get stuck in the same traffic anyway.

"This is one of the pieces of infrastructure we need to relieve the crossing and there will be more need for other things later..."

She is calling for a deeper investigation into the root causes of congestion in the town to help come up with a much wider ranging solution to cut down queues and poor air quality.

She says she has written to government transport ministers about the issues and need for investigations into the traffic problems in Dartford.

It comes as a consultation led by National Highways into the community impact of the proposed LTC comes to a close tonight.

Comments can be made on the project website here.

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