Sittingbourne and Sheppey drivers can look forward to road improvements after a huge investment was announced by the government.

The Stockbury roundabout is one of several key Kent roads and junctions in line for £1.4 billion that will be spent improving conditions.

It is unclear exactly how much cash will be spent on the junction, which joins the A249 with the M2, but it is understood the work will significantly boost its capacity.

Transport secretary Patrick McLoughlin and chief secretary to the treasury Danny Alexander set out details of the nationwide roads investment in Parliament.

MP Gordon Henderson first indicated there could be funds earmarked for the roundabout at a meeting held last month at Knauff, at Kemsley Business Park.

The Tory has spent months campaigning for improvements to the road, including a suggestion that congestion could be eased through switching off the traffic lights.

On Monday’s funding announcement, he said: “I am absolutely delighted – the road has such a big impact on our area.

“I will continue to press for a range of road improvements in Sittingbourne and Sheppey, including completion of the Northern Relief Road [in Sittingbourne] and construction of Junction 5a of the M2, although my next priority is getting something done about the safety on the Sheppey Crossing.”

The Kent roads money is part of a total £15 billion that will be spent on problem roads across the country.

Safety concerns over the crossing were raised in a Westminster Hall debate by Mr Henderson.

In a speech made last week, he called on transport minister John Hayes to put pressure on the Highways Agency to carry out a fresh review of the bridge.

This follows the 150-vehicle pile-up in September 2013, in which several people were seriously injured, and the crash which claimed the lives of a mother and her eight-year-old son in July.

He also recounted the experience of Islander Eileen Nichol, who broke down on the bridge last month and said she could only sit in her car, terrified, as others went past her at great speed.

Mr Henderson said: “Something must be done, and it must be done soon.

“My constituents and I have waited for more than a year for the Highways Agency to undertake a review of safety on the bridge.”

He called for matrix warning signs, average speed cameras to enforce the 70mph limit, better CCTV monitoring to spot breakdowns sooner and emergency telephone and refuge bays so that people did not have to stay in their cars if they broke down.

In his response, Mr Hayes said the Highways Agency was already undertaking a review and was examining options for various potential improvements.

He said: “I do not want to over-dramatise, but given what he has told us today it seems important that we act very promptly indeed once the investigations are complete.”

He suggested a meeting be held within 14 days of the release of the findings [of last year’s crash] to produce some preliminary proposals.

Labour borough and county councillor Roger Truelove said he welcomed the news of the much-needed funding for Junction 5 but argued it was not enough.

The Chalkwell ward representative said: “We also need to see progress on the Northern Relief Road and on the Grovehurst Junction with the A249. I was frankly most disappointed that the local MP did not specifically mention the Northern Relief Road in his short adjournment debate in Westminster Hall last Wednesday.”

In his speech, Mr Henderson also called for improvements to the Stockbury and Grovehurst Road roundabouts and the Barton Hill Drive and Lower Road traffic lights in Minster.

He said the A249’s dual carriageway should be extended from Queenborough Corner traffic lights – along Brielle Way – to the docks if Peel Ports’ plans for expansion went ahead.

Mr Hayes said the Highways Agency would liaise with Kent County Council on the Barton Hill Drive traffic lights as the local authority had responsibility for the road.

He said the government would also work with local partners to assess the Grovehurst Road roundabout, and improvements to the A249 would need to be considered should the docks expansion go ahead.

It is hoped more details about the Stockbury work will be unveiled after the chancellor’s autumn statement today (Wednesday).