A 20mph speed limit could be introduced in the centre of Oxford once CCTV cameras have been installed to enforce the city's transport strategy.

The county council's executive board ageed a £180,000 surveillance system to cover High Street, George Street, Castle Street and Magdalen Street East.

The new cameras will mean drivers are much more likely to face a fine if they flout a daytime ban on cars. Footage from the original High Street camera could not be used to prosecute the hundreds who ignore the restriction, due to a legal loophole.

Four new cameras are expected to be installed over the next few months once the necessary Government legislation is in place.

Eddie Luck, assistant director of transport development, said: "We don't want to put speed humps or other physical measures in to bring it about, but will use a series of low-key measures including road markings and signings. Some buses are travelling faster than we want them to, and it can be quite intimidating for cyclist and pedestrians."

Traders say they want to be fully consulted about the camera plan. They are particularly concerned about the effect on delivery drivers in George Street.

Oxford High Street Business Association spokesman Graham Jones said: "George Street provides the only access to New Inn Hall Street, Shoe Lane, and the servicing area at the rear of the Clarendon Centre and Queen Street as well as to the areas adjacent to Gloucester Green."

The executive board will discuss the proposed 20mph limit on April 15.