A £700,000 scheme to double the size of Oxford's Thornhill park-and-ride car park has been approved by county councillors.

An extra 460 spaces are planned at the car park off the A40 at Headington to take the capacity to about 950. The move will ease pressure at the site, which is often full.

The county council strategy committee has authorised officers to continue talks to take over the lease.

At present, the car park is leased to Oxford City Council by landowners Shotover Estates but the terms of the agreement have prevented parking fees being charged.

If county council negotiations on the lease are successful, parking charges will be allowed, although it is still not clear which local authority will be responsible for running the car park and charging customers.

The city council is expected to continue running the car park until March 2002.

Talks between the two councils will continue on how all city park-and-ride car parks will be managed after that date, and what charges should be made.

Noel Newson, the council's group manager for sustainable transport, said: "We look forward to completing negotiations with the landowner which will enable us to double the size of the car park next year.

"The increase in size should relieve pressure on local residents because some drivers park in nearby streets when the car park is full.

"The expansion will also enable more people living on the east side of Oxford to get into the city centre."

The extension, immediately west of the present car park, would use the same access and would incorporate security lighting and cameras.

The county council also plans to build a new 800-space park-and-ride near the grain silo site south of Kidlington, and hopes to start work on the project next summer.