Letter: Slow it down

Sir: Oliver Howarth (letter, 13 February) points out that journeys take longer at lower speeds and cutting speed limits would mean more cars on the road at any one time. However, the carrying capacity of a road (the maximum number of vehicles reaching any point per hour) is far greater at lower speeds, since the safe stopping distance increases, roughly, as the square of the speed.

Pedestrians on busy roads are best catered for by clearly marked crossings or bridges. Even a jay-walker is far more likely to be hit by a fast-moving vehicle.

ALAN COCK

London E3