§ Mr. Llew SmithTo ask the Secretary of State for Transport if he will make a statement on the cost evaluation techniques used by his Department for major highway on-line improvement schemes with particular reference to the range of costs associated with the maintenance of traffic flows; and what reliability tests are applied to these evaluations. [32037]
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§ Mr. WattsI have asked the chief executive of the Highways Agency to write to the hon. Member.
Letter from Lawrie Haynes to Mr. Llew Smith, dated 12 June 1996:
The Secretary of State for Transport has asked me to reply to your recent question concerning the cost evaluation techniques used for major on-line improvement schemes.The Agency uses similar economic evaluation techniques for all the schemes in the Road Programme whether they be a bypass on a new alignment or an on-line widening. This involves the assessment of all the capital and maintenance costs of the scheme and the benefits to road users in reduced congestion and accident savings over a 30 year period. All these costs and benefits are discounted to a common price base and present value year to give a Net Present Value for the scheme.Traffic forecasts for such a long period into the future are naturally subject to uncertainty because of the effects of factors such as the price of fuel and the future economic performance of the country (in terms of GDP) for which assumptions have to be made. The Department of Transport has, for some time, recognised this uncertainty and publishes "high growth" and "low growth" national traffic forecasts, representing the range of what is likely to happen. These forecasts are incorporated into the Department of Transport's COBA (Cost Benefit Analysis) computer program which is used to assess the day to day benefits in terms of time saving, fuel savings and accident reductions. The enclosed booklet "GETTING THE BEST ROADS FOR OUR MONEY" describes the basic principles.The cost of delays and accidents during construction and maintenance works over a 30 year period are assessed using the Department of Transport's QUADRO (Queues And Delays at Roadwork) computer program. This program assesses the cost of delays in terms of increased fuel cost, vehicle occupants' time and accidents. It can take account of different traffic management arrangements, e.g. number of lanes closed, length etc. including the availability of a suitable diversion route.All appraisals are scrutinised by Departmental or Agency staff as agreed by the Department.The parameters and values used in the computer programs are based on research and updated when necessary. The Highways Agency's Research Programme includes projects which have the objective of improving network safety and efficiency by reducing delay and accidents at roadworks. In the current financial year the following projects may produce benefits in this area:-Study of Accidents and Incidents at Roadwork
This study will update the current information about the causes, types and frequencies of accidents and incidents at roadwork and may identify improvements to the techniques used.Merging Traffic at Roadwork
This research will provide information about possible ways of improving the capacity at merge points resulting from lane closures.
If this work produces information that could affect the calculations in QUADRO or COBA the results will be passed to the Department's Central Transport Group for incorporation into the computer programs.