| 摘要 |
An auxiliary barrier (7) located on the opposite side of the track (2) to the main barrier (4) is lowered and raised at the same time as the main barrier. Sufficient distance for a car or lorry is left between the track and auxiliary barrier, so that a vehicle crossing the track when the semaphores (5, 12) are flashing will be able to get off the track in time, but will be prevented from driving off straight away by the auxiliary barrier. |
