asked the Minister for the Environment the approximate cost per unit of constructing a motorway and of constructing a dual carriageway.
Written Answers. - Road Construction Costs.
155.
The unit cost of constructing road schemes depends on a variety of factors including land acquisition costs; the amount of earthworks; type of ground; traffic levels which determine pavement type and depth; and particularly, in the case of motorways, the extent of severance and resulting accommodation works; and the number of structures including interchanges to be provided.
In preparing the roads programme, an average gross cost of £3 million per kilometre is currently assumed for motorways and £2 million for dual carriageways in the case of schemes that have yet to be designed.