Discussion on Paper 5

R. E. FOOT, Sir Owen Williams and Partners

The Authors have stated that bridges will form a large part of the cost when roads are built in Britain's cities. As consultant engineers for the Midland Links motorways my firm agrees. On rural lengths of motorway the cost of structures represents about 30% of the cost per mile, whereas on contracts in the Midlands, where there are lengths of viaduct, the structural cost is 70% or more per mile. Based on average tender prices, this means an increase in cost from £800 000 per mile for rural motorway to £2\ million for a motorway with a substantial length of viaduct. On one contract, which is entirely viaduct, the cost rose to £3% million per mile, although we feel we have achieved a considerable economy by standardization.