Sir – In Oxford it is not an unusual occurrence to see the traffic (waiting to get through Frideswide Square with its 35 traffic lights) extend back into St Giles, thus creating a vast amount of pollution to the atmosphere. The alternative is a six-mile detour, again creating pollution.

When constructed, common sense would have indicated a circulatory system with no right turns. Some time ago, this folly was recognised and a proposal made to rectify, but so far this has been talk with no action.

Derek Sherwood , Headington