Patent ID: 8576115

Claim:
A vehicle length sensor for a vehicle having a length, the sensor comprising a mount for mounting the sensor on the vehicle and a detection circuit arranged to measure, in use, the length of the vehicle to which the sensor is mounted, wherein the length is the length of the entire vehicle, including any trailer, or at least the length from where the sensor is mounted on the vehicle, including any trailer, to a rear end or a front end thereof, wherein the sensor is arranged to detect any other vehicles which are, in use of the sensor, alongside the vehicle to which the sensor is mounted, wherein the sensor is arranged to determine the distance of the other vehicles alongside the vehicle from the vehicle in a direction parallel to a direction of travel of the vehicle, and wherein the sensor is arranged to provide an indication to a driver of the vehicle, in use, of whether there are any vehicles alongside the vehicle for a distance of the length of the vehicle, plus an optional safety margin.