We’ve gone off the rails and opted for road to ruin

ACCORDING to Eileen McCarthy of Arup (Irish Examiner, July 9), the Cork-Limerick motorway will save 70 lives over a 30-year period, based on 35 fatalities in 20 years on the roads which it would replace. But this simplistic calculation works out to 52.5 lives saved, not 70, and assumes no one will be killed on the motorway.

All things being equal, motorway-type roads are less dangerous, but all things are not equal. Road-building generates increased traffic volumes, with accident ‘migration’ to other roads and risk compensation taking place.

Vehicle speeds are higher on motorways, and British studies on fatalities are inconclusive. Obviously there are no pedestrian and cyclist fatalities because they are banned – these accidents are ‘transferred’ to other roads.