DELAYS in a multi-million pound railway scheme will have a damaging knock-on effect on A34 congestion, Oxfordshire motorists have been warned.

County transport planners hoped that the expansion of Reading's rail station would be the first in a series of major schemes offering to ease the prospect of long-term chaos on the trunk road. But County Hall has now heard that the plan to increase capacity at Reading will not be complete until late 2010.

And there was a further blow for motorists as it was confirmed that work on a replacement A34 flyover south of Pear Tree will start as early as 2008, taking two years to complete.

The expansion of both Reading and Oxford railway stations are viewed by Oxfordshire County Council as crucial to reducing the huge number of HGVs on the A34, by encouraging them to switch to rail.

An engineering report at the end of last year confirmed that it was technically possible to expand Oxford's station with additional tracks built across Botley Road. But the cost of adding two new platforms at Oxford is put at between £68m and £113m.

The leader of Oxfordshire county council, Keith Mitchell, said: "The Oxford scheme seems to have disappeared somewhere in the rail industry. It does not look to be a high priority."

But Mr Mitchell said it was now clear that the capacity upgrading at Reading would not be going ahead until the end of the decade.

Reading deals with passenger trains to the South West and South Wales as well as huge amounts of freight traffic from the south coast ports.

Mr Mitchell said: "It is good news that Reading is on the agenda but bad news that it will take so long. This means some of the options for easing the load on the A34 will not come on stream anywhere quickly enough.

"We all know that there has been a string of tragic recent accidents on the A34. This has prompted legitimate calls for the Government to give a much higher priority to increasing capacity along the corridor."

The one crumb of comfort is that new signalling and track must be installed at Oxford by 2009, giving rise to hopes that platforms might be added at the same time.

Mr Mitchell said he would be pressing for an urgent study into the A34 at a meeting with the head of GOSE (Government Office for the South East).

At present there are only two passenger and freight lines at Oxford station and only two platforms. The huge cost of any expansion results from the difficulties of carrying additional track over Botley Road.

It emerged this week that the new A34 flyover will cost £30m, with the Highways Agency promising it would try to keep traffic disruption to an "absolute minimum" by keeping all lanes open, at least during the daytime.

The viaduct is 45 years old and due to the heavy volume of traffic has deteriorated to the point where it no longer complies with design standards. They say it is now cheaper to replace it instead of continue with repairs.

The new viaduct may be built alongside the current viaduct. The Highways Agency is currently considering several options as to how traffic will be managed and where the new structure will be built.

Spokesman Martin Deller said: "The option we favour at the moment is using half of the newly-built bridge and half of the old bridge. We want to keep two lanes of traffic moving at all times. There won't be traffic lights during the daytime. If one lane does have to be closed, it will be at night.

"Workmen will be working 24 hours a day on the construction of the viaduct."

An online poll of The Oxford Times readers showed support for the A34 to be turned into a motorway. Asked if the A34 should be made into a three-lane motorway, 55 per cent said 'yes' and 28 per cent 'no'. Seventeen per cent said no but wanted road tolls to be introduced.