Only lower speed limits will solve traffic problems | Letters

Lower, properly enforced speed limits are the key to tackling all the costs and nuisances of traffic (Letters, 25 March). A report from the Policy Studies Institute in 1996 concluded that speed limits on main roads should be reduced, with the speed limit on motorways certainly no higher than 60mph. The immediate consequence of strict enforcement of lower limits would be reductions in road crashes and casualties, fuel consumption, CO₂ emissions and noise. Capacity would be increased. Traffic levels would be reduced by checking and then reversing the tendency for car journeys and lorry hauls to increase in length.

The default speed limit in towns should be 20mph. Combined with bus priorities, measures to make walking and cycling safer and more agreeable, and planning policies to encourage smaller, local shops and other facilities, lower speeds in towns would have a profound influence on modal choice and journey length. The best way of enforcing speed limits is by variable speed limiters on the vehicle. They can either be operated by the driver or activated externally. Both types of speed limiter have been shown to be technically feasible and inexpensive.