To ask the Secretary of State for Scotland what national guidelines are available to local authorities to help them to calculate the probable volume of traffic from a proposed development. [79918]

Guidelines are published by the Institution of Highways and Transportation on the preparation of Transport Impact Assessment (TIA) Reports. These are widely accepted as the national standards. A local authority consortia also maintain and update continuously a UK National Database of trips generated by different types of development. These data are used in the preparation of a TIA.A TIA report would normally be requested by the local authority from a developer in support of a planning application. The impact, if any, on trunk roads would be included within such reports.From 1 July 1999, this will be a matter for the Scottish Parliament.