At present, many people use their cars for daily commuting. Unfortunately, the vehicle occupancy rate is relatively low, averaging 1.08 persons per vehicle (figure for Belgium). This leads to traffic congestion and pollutant emissions. Carpooling is a very effective solution to limit the number of vehicles on the road and thus reduce traffic. Therefore, it is becoming more and more necessary to encourage carpooling in urban areas.

This is done by reserving lanes only for carpooling vehicles, allowing users to save considerable time. In order to ensure that the carpooling lanes are only used for carpooling purposes, a control system must be implemented.

Carpooling solutions monitor the proper use of the carpooling lanes by counting vehicle passengers. Below a certain number of passengers, the vehicle is not allowed to use the reserved lane and must pay a fine. Equal or above this same threshold, the vehicle may use it without any restrictions.

The solution also makes it possible to define exceptions (white list) or to define certain periods when the control system is inactive, i.e. the carpool lane will operate as a normal lane for all vehicles during these precisely defined periods. In this case, the authorized travel times on the lane are often displayed to the drivers thanks to VMS positioned before the entrance to the carpooling lane section.