§ Mr. SpearingTo ask the Secretary of State for Transport if the COBA criteria for construction of new roads being studied in his London transport assessment studies will apply with, or without modification, to any selected road schemes.
§ Mr. Peter BottomleyAny road scheme arising from the London assessment studies will be appraised using the Department's normal scheme appraisal methodology. This includes a full economic and environmental assessment.
§ Mr. SpearingTo ask the Secretary of State for Transport what significance is attached to saving in journey time in current COBA assessments of new road schemes; and what weighting is given therein to design speeds of new roads.
§ Mr. Peter BottomleyUser benefits on COBA are derived from savings in journey times on links and at junctions, accidents and vehicle operating costs. In a representative scheme 90 per cent. of the benefits could be attributable to time savings. Design speeds are consistent with the anticipated vehicle speeds on the road and are contained in Department of Transport departmental standard TD9/81, "Road Layout and Geometry: Highway Link Design."