Commuters queueing in their cars through Winchester's rush-hour traffic might well smile at the idea of bringing the city's speed limit down.

But that's what the council aims to do after outline plans for a city centre-wide 20mph limit received widespread support from members.

In as little as 18 months, the entire one- way system, along with many other central streets, could see the 20mph signs going up.

But police have said they will not provide any special enforcement of the new limit, prompting fears drivers will just ignore it.

The new limit would be designed to cut accidents and improve the flow of traffic through the centre.

The plan is based on the success of a 20mph scheme in Salisbury where, although speeds dropped only slightly, injury accidents were halved.

Stretching from St Giles' Hill to Oram's Arbor and from the Art College to Kingsgate Street, Winchester's 20mph zone would encompass the entire centre.

Most controversial aspect of the idea is likely to be a plan to reduce North Walls to one carriageway, with cycle paths and a bus lane.

Introducing the new limit across the city is expected to cost £30,000-£40,000 with extra costs on top for a hefty publicity push.

The new limit is intended to be introduced at the same time as the controversial Bar End park-and-ride extension.

Rodney Sabine, leader of the city council, said: "We hope this will make the city centre safer for people while not making it too difficult for drivers."

The city's chief engineer, David Marklew, said the council was going to investigate the likely safety impact of the scheme.

"In the past, there have been some serious accidents in the city centre. We will be conducting before-and-after accident studies. We hope that the scheme will also make the city centre environment more pleasant for pedestrians and cyclists.

"It should also help traffic in the city to flow more smoothly."

When city councillors have agreed the final details, the scheme will be referred to the county council for the final say.