The automatic monitoring system receives inputs from traffic counting loops, meteorological stations, cameras and automatic incident detectors. It is implemented using a roadside network of fibre optic cables.
- Traffic counting loops, located at approximately 20 km intervals, automatically calculate traffic densities, flow rates and the proportion of heavy goods vehicles. All this information is used to evaluate journey times.
- Meteorological stations sited along the motorway measure changing weather conditions. Where appropriate, these stations send alerts to control rooms, making it possible to take preventive action (such as salting) and to give customers advance warning by radio or using variable-message signs.
- Cameras installed in sensitive locations help to monitor motorway interchanges and other potentially problematic areas.