设备安装在驾驶出租车一些单位(通常是较新的Anything with wheels on it which can run on the track including locomotives, carriages, goods wagons, and maintenance vehicles.
" class="glossaryLink ">车辆)，记录列车速度/制动情况/美国焊接学会(AWS)指示Two sets of two electronic loops are set in the track before signals where a SPAD would be most likely to put a train into risk of being involved in a collision. The loops are energised when the signal is red and emit electromagnetic fields. When an antenna on the train detects the field emitted by the first loop of a pair it starts an electronic timer. The field emitted by the second loop of the pair stops the timer. The first pair of loops encountered are spaced so that the timer on the train can calculate whether the safe speed for approaching the signal is being exceeded. If it is, the brakes are automatically applied. The second pair of loops are situated closer to the signal and are placed very close together such that the safe speed is effectively zero. TPWS will be used in conjunction with the existing AWS.
" class="glossaryLink ">课程结业者将加入慈善研讨课程在每个旅程上收到的激活等。“黑箱”的内容可由某些车厂的专业设备下载，以列印资料，以便调查SPADS等。
