asked the Secretary of State for Transport what is his estimate of the current average costs involved in building a mile of motorway and a mile of principal trunk road.

Construction costs vary widely depending on the nature of the terrain through which new roads are constructed and whether the location is urban or rural. On rural schemes for which contracts were let in the period 1973–1978, costs—at August 1978 prices—were:

—in the range of £1·43 million to £7·22 million per mile for dual three-lane motorways with a mean of £2·49 million;

—in the range of £1·06 million to £3·98 million per mile for dual two lane motorways with a mean of £1·81 million; and

—in the range of £0·39 million to £3·37 million per mile for dual two-lane all purpose trunk roads with a mean of £1·43 million.

Land costs and rehousing costs, which are excluded from these figures, vary widely and can account for 10 per cent. or more of the overall cost of rural schemes.