HC Deb 22 March 1993 vol 221 c481W
Ms Walley

To ask the Secretary of State for Transport if he will set out the rules which are used for determining which options for road improvement schemes provide the best long-term value for money.

Mr. Kenneth Carlisle

The assessment of road scheme options takes into account all relevant effects.

Some of the effects are valued in monetary terms. These are savings in time, accidents and vehicle operating costs as well as construction costs. A net present value of these effects for each option is calculated over a 30-year period, using standard computer programmes. The techniques are described in the COBA, QUADRO and URECA manuals published by the Department.

Environmental effects are not valued in monetary terms. They are subject to a comprehensive assessment including noise, visual, ecological, air quality and other relevant effects.