The most common technique for detecting the presence and position of vehicles at traffic signal controlled junctions is using inductive loops cut into the road surface. The loop inductance of this system decreases when a vehicle is present on top of it, and an array of loops carefully positioned at a series of traffic lights can determine which lane vehicles are waiting in. This data fed into a complex traffic management system can then be used to streamline traffic across a section of the road network, or through busy areas of towns and cities.
If inductive loops are installed by sub-standard or non-accredited suppliers careless resealing can result in moisture reaching the wires and changing the electrical characteristics of the loop. This could cause a system malfunction or could mean that rogue data is transmitted to the traffic management system.
All Bridgepoint Road Markings inductive loop cutting is carried out to Highway Sector Scheme 8 regulations and to MCH 1540 Specifications as set out by the Highways Agency. In Northern Ireland we carry out road marking and traffic census term contracts for DRD Roads Service, and have a contract with Siemens Traffic Controls for the installation of inductive loops at traffic signals for the whole of Northern Ireland. In the Republic of Ireland we are a National Roads Authority (NRA) approved contractor.