HC Deb 15 May 1989 vol 153 c11W
Mr. Tim Smith

To ask the Secretary of State for Transport how many of the noise bunds and barriers alongside the M25 are(a) earth bunds with planting and (b) walls or fences.

Mr. Peter Bottomley

The information is as follows:

Miles
Noise bund 15.5
Noise barrier 13.5
Noise barrier on bund 3.0

Mr. Tim Smith

To ask the Secretary of State for Transport, when, pursuant to his answer of 24 April,Official Report, column 447, he expects to be able to list the latest available traffic flows using the M25 entry and exit slip roads; and whether he will at the same time list in the Official Report the matching main carriageway flows in each direction between interchanges.

Mr. Peter Bottomley

These traffic flows will be made available when the report of the M25 review is published.

Mr. Tim Smith

To ask the Secretary of State for Transport if he will state, for the M25 traffic flows listed in theOfficial Report on 24 April, columns 445–46, the factors his Department uses for correcting for seasonal effects; from what source these are derived; and how these factors differ from those used for other trunk roads and motorways.

Mr. Peter Bottomley

The M25 traffic flows were adjusted for seasonal and other effects by scaling to automatic counts for the full year. Complete annual counts are not generally available for other roads. Annual average daily flows are usually estimated from 12-hour counts using a common set of adjustment factors for each road class. These factors are derived from analysis of regular monthly censuses at 170 core sites.