§ Mr. Damian Green
To ask the Secretary of State for Transport what assessment his Department has made of reductions in traffic accident rates at vehicle activated sign sites; and if he will make a statement. 
§ Mr. Jamieson
Vehicle activated signs are used predominately where there are concerns about inappropriate speed. They are not designed to deal with excessive speed. Research into the effectiveness of vehicle activated signs at a range of locations was carried out by TRL Ltd. on behalf of the Department for Transport in 2002. Results of this work concluded that across all sites there was a 31 per cent. reduction in accidents following installation. In addition where vehicle activated signs were used to remind the driver of the speed limit in force, speed reductions of between three and nine mph were achieved. Where installed to warn drivers of a potential hazard, reductions of up to seven mph were achieved. Guidance on the use of vehicle activated signs, is available in the Libraries of the House (Ref: Traffic Advisory Leaflet 1/03—Vehicle Activated Signs).