French radar will check number of car occupants on carpool lanes

It uses thermal sensors to do its job and will start issuing fines

In November 2023, on Road 137 leading to the city of Rennes (France), an upright-standing black box appeared on the side of the motorway. This radar, however, doesn’t measure the speed of passing vehicles as one might initially assume – instead it checks how many passengers are there in the vehicles using the carpooling lane.

The way the radar works is fairly simple – it uses a thermal vision camera to detect the number of occupants in the cars. There must be at least two of them in order to have a right to usage in the lane.

According to its manufacturer, based in Burgundy (France), it has an error rate of 1% and works in all climate conditions, day and night.

The installation of the rather itself coincided with the creation of the carpool lane, which was previously only used by public transport and emergency services vehicles. Its creation was seen as a solution to the increasing number of traffic jams during peak hours. Studies have shown that more than 85% of vehicles are only occupied by their drivers, which means that adding a carpool lane could dilute the traffic and encourage people to share their rides on their way in and out of the city.

Other French cities are also installing the device

The local traffic authorities allowed a nearly 8-month grace period in order to allow drivers to adapt to the new road reality. Starting on 17 June, however, the carpool radar will start issuing fines if it detects only a single occupant in the vehicle using the rightmost lane.

This means that offenders can expect to pay 135 euros if driving alone in the lane stretching between the municipalities of Noyal-Châtillon-sur-Seiche and Chartres-de-Bretagne, near Rennes.

The Britanny regional capital will not remain the only French city to introduce the carpool radar. Other municipalities that are in the process of creating carpool lanes, accompanied by the innovative devices, are Grenoble, Lyon, Lille, Nantes and Strasbourg.