Sir – The new speed limit in Oxford (if enforced) will do more than save life and limb. There should be no doubt that people change their behaviour in the face of the threat posed by traffic speeding through their towns and villages.

They walk and cycle less, for example. A reasonable curb on driver liberty will greatly increase that of others.

It will also reduce congestion, energy consumption, pollution, and carbon emission.

What is needed now is the limit extended to all county roads through every town and village, and proper enforcement.

The police must be required to enforce the law, which they currently fail to do, and have even stated they will not do.

The AA and RAC began by opposing speed limits of any kind, and have always campaigned against their reduction. Both legislators and the police have been cowed by them for far too long.

Dr Ian East, Islip