Graham Cribb (Have Your Say, July 10), in responding to my letter, claims I am calling for 20mph limits everywhere including motorways.

Speed limits are a compromise between safety and traffic flow. They are necessarily dictated by those looking at the whole picture and with reference to accident stats, not driven by self-interest.

Very significant reductions in serious accident rates can be achieved with small alterations to speed limits. In Hull, 20mph suburban zones brought a 90 per cent reduction. Indeed, even in the Netherlands, with their cycle and pedestrian-friendly approach to road design, 25 per cent reductions result from dropping 30mph zones to 20.

Mike Chalkley, Cowper Road, Bournemouth