Having been recently adopted by Stagecoach, the TailGuardian decal is now available to all commercial fleet operators to help protect their vehicles, staff and customers.
The decal can be applied to the rear of commercial vehicles. If a driver following the vehicle can see the speed that they are driving at with a 'back off' hand over it, they are too close.
Each 'back off' hand is visible when the safe distance has been breached - so if a driver following the vehicle is doing 50mph and can see the overlay on top of number 50, he is driving too close.
The concept works by using filters to enhance parts of the decal - which the brain 'ignores' at a distance. By calibrating the images differently, each 'back off' becomes 'pre-programmed' to appear at the correct set distance, while remaining invisible outside that distance.
Chief inspector Tom Forrester, Grampian Police, said: “TailGuardian is a fantastic concept and it is encouraging that Stagecoach are putting them on its buses."