Motorists could be facing new 20mph speed limits in Oxford city centre within eight months.

Transport chiefs are looking at cutting speeds across the city from 30mph to 20mph and last night county councillor Ian Hudspeth gave the first timetable for the changes.

And he told the Oxford Mail the shift was unlikely to affect the main arterial roads.

Campaigners have already succeeded in getting 20mph limits on some residential streets, and parts of Cowley and Banbury roads.

At a county council meeting next month, Mr Hudspeth, the cabinet member for transport, will consider a report outlining how and where 20mph limits are to be introduced.

Mr Hudspeth said: "The report is out next week and it will set out the locations for 20mph limits, a timeline and costs.The main thrust will be to introduce 20mph limits on all residential streets but not on the arterial routes within the ring road.

"It is not realistic to have 20mph limits on the Abingdon, Banbury, Iffley, Woodstock and Botley roads 24 hours a day, because at 11pm the roads will be clear.

"If there are 20mph limits on residential streets that should reduce drivers' speeds on the main routes."

Mr Hudspeth said the first stage would be to create a 20mph zone in the city centre, but the streets to be included have not yet been finalised.

"On Marston Ferry Road, for example, there is a 40mph limit, so a 20mph limit there might be considered too slow," he added.

"Streets such as St Clement's, St Aldate's and St Giles would be included.

"I would hope the city centre 20mph limit would be in place by February/March 2009, with 20mph limits established in residential streets on a staggered basis throughout 2009.

"The recommendations of the report in principle will go out to public consultation because we want as much feedback as possible on this.

"There is a difference between a 20mph limit and a 20mph zone, because a zone can involve road humps, which some residents might object to.

"We want to do everything we can to educate drivers about speed within the confines of this medieval city and if we can reduce the speed of traffic then cyclists and pedestrians will feel safer on the roads."

The transport meeting takes place on Thursday, July 17.

David Jacques, 68, a member of the cycling campaign group Cyclox, and supporter of the Life Begins at 20 campaign, said: "Cyclox welcomes the introduction of 20mph limits in residential streets but is calling for arterial routes to have 20mph limits too because drivers often travel at 45mph along them."

Corinne Grimley Evans, of the Oxford Pedestrians' Assocation, added: "The major routes which have schools and houses along them such as Banbury, Woodstock, Cowley, Iffley and Botley roads should be included."

The council estimates that implementing the 20mph limits will cost a total of £300,000.