asked the Minister of Transport whether the proposed dual three-lane layout for the M25 M4–M40 section conforms with the provisions of technical memorandum H6/74; whether the layout complies with paragraph 4 of appendix B of the memorandum; and, if not, for what reasons his Department decided to ignore the design standards laid down, especially in view of the fact that the M25 is forecast to carry a significant proportion of heavy vehicles.

The predicted volume and pattern of traffic for the late 1990s slightly exceed the figure at which, according to technical memorandum

Financial year						Mileage of new trunk road motorways opened	Mileage of new and improved all-purpose dual-carriageways Opened	Mileage of new and improved all-purpose single-carriageways opened
1974–75	…	…	…	…	…	76	51	4
1975–76	…	…	…	…	…	118	76	15
1976–77	…	…	…	…	…	43	82	14
1977–78	…	…	…	…	…	56	62	22
1978–79	…	…	…	…	…	41	60	—
1979–80*	…	…	…	…	…	58	18	3
1980–81*	…	…	…	…	…	36	21	18
*Forecast

In addition, 5½miles of motorway widening is expected to be completed in 1980–81. Of the totals for all-purpose roads listed above, about 13 miles in 1976–77, 21 miles in 1977–78 and 2 miles in 1978–79 were substantial improvements to existing roads (including dualling and junction improvements): the remainder were new routes, including bypass schemes.I regret that information on the mileages of substantially improved roads included in the figures for 1974–75 and 1975–76 cannot be provided without undue effort and expense.