HC Deb 24 May 1993 vol 225 cc413-4W
Mr. Hinchliffe

To ask the Secretary of State for Transport if he will make a statement on the accuracy of the national road traffic forecasts index.

Mr. Kenneth Carlisle

The national road traffic forecasts give forecasts of traffic by type of vehicle on all roads in Great Britain. The current forecasts were issued in 1989, based on 1988, and are provided up to 2025. The table compares the forecasts in terms of all vehicle kilometres with the outturn. The forecasts are given in a range between low and high.

They are long-term forecasts, and are not expected to be completely accurate year on year, or over short periods.

Indices of traffic—1988 = 100
Year Forecast of all Traffic1 Outturn Traffic1
Low High
1988 100 100
1989 104 105 108
1990 106 109 110
1991 108 113 110
1992 110 117 108
1 All motor vehicles except two-wheelers.

The 1992 statistics of outturn are provisional.

Mr. Hinchliffe

To ask the Secretary of State for Transport if COBA 9 cost benefit analysis systems are to be replaced.

Mr. Kenneth Carlisle

The Department uses the principles of cost benefit analysis to assess the economic viability of schemes in the national road programme. The COBA program incorporates the principles of cost benefit analysis and is used to assess the majority of schemes. The techniques and parameters within the program are continually under review and occasionally changes have to be made as the results of new research become available. COBA 9, the version currently in use, is a flexible program and generally parameter changes can be made by the user following instructions issued by the Department. However, periodically it is necessary to revise the program itself and a new version, COBA 10, is currently being developed for release later this year.