The A75 Gretna Green-to-Stranraer road is the main route through Scotland to the ferry port servicing Northern Ireland
With over 1.5m vehicles, including over 200,000 heavy goods vehicles, using the road each year, Transport Scotland commissioned Clearview Intelligence to conduct speed surveys at 12 locations between Gretna and Stranraer.
Speed limits differ according to vehicle type, such as passenger cars, vans and heavy goods vehicles. The surveys highlighted a recurring problem with the 85th percentile speed being unacceptably high, most notably with HGVs.
Clearview, working with the road operator, Scotland TranServ, developed a solution that identifies speeding per vehicle type and provides an alert to the driver.
Six locations were selected for maximum impact. However, problems with speeding vehicles are not confined to built-up areas, so the solution needed to be solar powered to cater for rural locations where it is impractical or impossible to connect to a mains supply.
Clearview installed solar powered vehicle “detection count and classify” equipment to record a combination of vehicle classification with identification of vehicles travelling above the speed limit.
Each of the six sites features two vehicle-activated signs (VAS) facing each direction of travel. The vehicle detection units communicate with the VAS to trigger a display showing the appropriate speed limit warning according to vehicle type.
Clearview said that this kind of vehicle-activated, dynamic speed warning system serves as a highly visible and immediate reminder to drivers to monitor and manage their speeds appropriate to the legal limit of their vehicle’s classification.
