Road safety device to prevent a vehicle entering a one way road in the wrong direction, uses Doppler radar to detect vehicle approaching in wrong direction on slip road and then generates warnings

摘要

The safety device has a Doppler radar unit (A) with the beam (F1) directed along the slip road so that it normally sees vehicles moving away from it. An approaching vehicle is going to enter the road against the traffic, and triggers an audible and a visible signal to alert the driver. If this is ignored a second radar (B) confirms the approach and generates a radio alert.