A revised roundabout at Heyford Hill funded by Sainsbury’s could signal major improvements to Oxford’s ring road, The Oxford Times can reveal today.

Sainsbury’s has submitted plans to create a new ‘hamburger’ junction — complete with traffic lights — similar in scale to the scheme completed three years ago at the Green Road roundabout in Headington.

The firm says the scheme would improve access to its Heyford Hill store and relieve congestion at a bottleneck.

The county council confirmed the work, if approved, would be part of a wider scheme that could eventually see an extra lane built eastbound between the Abingdon Road roundabout and Heyford Hill. With the store to be substantially extended, Sainsbury’s wants to cut two new lanes through the centre of the Heyford Hill roundabout, with additional lanes created on the approaches to the roundabout to improve traffic flow at the congested junction where the A4074 meets the southern and eastern bypasses.

But it has emerged that the Sainsbury’s plan could be the first phase of a far bigger scheme being drawn up by Oxfordshire County Council.

The council disclosed to The Oxford Times this week that it was working closely with Sainsbury’s to ensure the proposals at Heyford Hill fitted in with its plans to address congestion on the A34 and Oxford ring road.

David McElhannan, Sains bury’s development executive, said: “The works to the roundabout would be paid for by Sainsbury’s, meaning that these improvements would not need to be paid from public funds.” The company said it was not yet able to give details of the cost of the scheme, but Mr McElhannan added: “The proposals represent a substantial financial investment by Sainsbury’s.

“Whilst planning permission for an extension to our Heyford Hill store was granted last year, we are keen to see access to the store improved before the extension opens.

“The planning application, therefore, seeks to improve the safety and efficiency of the roundabout for the benefit of all users, including Sainsbury’s customers.

“If we are granted planning permission, Sainsbury's would look to commence construction works alongside the store extension in 2011.”

Ian Hudspeth, county council cabinet member for infrastructure, said: “We warmly welcome this third-party investment at a time when we are looking carefully at the southern approaches to Oxford.”

Mr Hudspeth said County Hall would be working with Sainsbury’s to ensure easing traffic flow at Heyford Hill did not resolve one bottleneck to create another nearby.

He said the idea of using empty land at the side of eastbound road between Abingdon Road and Heyford Hill to create an extra lane, possibly for buses, was only one option being looked at, as was the idea of creating a new filter lane to improve traffic flow on to the A4074.

Because of its position, the planning application from Sainsbury’s for the roundabout will be submitted to both Oxford City Council and South Oxfordshire District Council.

Meanwhile, in a bid to reduce congestion on to the ring road west of Oxford, traffic lights are being installed by the Highways Agency at the A34’s Botley interchange. They will be operational in June.