| 摘要 |
A road traffic control device comprises an open-topped elongate cylindrical housing adapted to be inset into a road surface, a triangular control member rotatably mounted in said housing for rotation about its longitudinal axis, and selectively operable means for rotating the control member such that any of the three sides may lie substantially adjacent the opening in the housing. Suitably, one side of the control member is flattened. Preferably, another side has a raised surface such that when such side is uppermost in use it protrudes above the level of the surrounding road surface and so provides a vibration to the wheels of a vehicle passing over the device. The remaining side of the device is provided with spikes such that when such side is uppermost in use the spikes project above the level of the surrounding road surface and puncture the tyres of any vehicle passing over the device. |
