Sir - We are pleased that the county council is expressing support for the city council's policy, agreed on a cross-party basis some 18 months ago, of a general 20mph speed limit across the city area (Report, June 13).

This is a vital step towards making the roads safer, and for helping to restore the roads to be genuinely shared space between those living in an area and those moving through it.

It will not be difficult to implement the lower limit, but the critical issue is in securing compliance from road users.

While selective police enforcement will undoubtedly be helpful in encouraging drivers to observe the new maximum, it will be much more effective over the longer run to ensure that road design and layout plays the greatest part in ensuring that people drive more slowly.

The city council, also on a cross-party basis, has for a number of years now, been urging the county to experiment with Home Zone approaches to urban design, in which we would gradually introduce street layouts that make it more difficult to drive fast, which encourage pedestrians and make streets safer for children and elderly people.

We know that full blown Home Zones are expensive to "retro-fit" into existing street design, but rather than resigning ourselves to inaction, the city council would like to work closely with the county to develop a programme of partial improvements that will support a successful introduction of the 20mph limit across the city. We are fortunate in having some of the world's foremost experts on urban design on hand in Oxford Brookes University's School of the Built Environment.

If we adopt Ian Hudspeth's "big bang" approach to the introduction of the lower limit, it is imperative that we also have in place budget and operational plans to support it with changes to residential street layouts - we cannot ask the police and their speed guns to take all the strain of the enforcement!

Bob Price, Leader of Oxford City Council, Colin Cook, City executive board member for planning and transport