§ Mr. Sheermanasked the Secretary of State for Transport (I) if he will give the percentage of roads likely to require major strengthening in the next five years;
(2) if he will give the percentage of roads having a residual life of 20 years before strengthening is required.
§ Mr. Kenneth Clarke[pursuant to his reply, 25 June 1981] the 1980 national road maintenance condition survey report. which is based on limited surveys of sample lengths of roads other than motorways gives the following information:
a. Percentages of road having residual lives of 20 years or more before strengthening is required. per cent. of mileage Trunk (excluding motorways) 66 Urban Principal 56 Rural Principal 73
b. Approximate percentages of road likely to require strengthening in the next five years. per cent. of mileage Trunk (excluding motorways) 14 Urban Principal 18 Rural Principal 12 We have no equivalent survey for the motorway, but detailed measurements and studies have shown that motorways built in the early 1970s will require some form of attention after an average life of about 15 years. I estimate that some parts of about 30 per cent. of motorways are likely to need strengthening in the next five years.