asked the Secretary of State for Transport whether he has yet decided whether concrete or tar surfaces are most cost beneficial for use on motorways; and what are the reasons for this choice.
It is not possible to make a general decision on which material is the more cost beneficial. Either of these materials can give equally good performance, although their relative merits may depend on the particular requirements of the scheme in question. For those reasons the Department usually allows for a choice of design and accepts the lowest tender, whether it be for concrete or bituminous materials or a combination of the two. Design standards are revised and updated in the light of information on performance and the results of research and development.