Sensor not working properly

Hi there, This is the manager of the shell garage, the traffic light doesn't pick up motor bikes and if a car isn't exactly on the white line the lights won't change. This causes cars to back up and some people tend to speed through the forecourt as a shortcut. I've seen people just go on a red light and seen people drive up the wrong side. The staff in the garage go out when they can to ask people to move up to the line. The traffic light number is 10 it's located at the small entrance of the forecourt. Thank you.