System for preventing vehicles entering motorway by exit road comprises rollers across width of exit road and covering length of 20 metres which can only turn in opposite direction to that required for vehicle to continue moving forward

摘要

The system for preventing vehicles entering a motorway by the exit road comprises rollers (4.1) which stretch across the width of the exit road and cover a length of 20 m. These can only turn in the opposite direction to that required for the vehicle to continue moving forward.