21. The STOP signal is a hand held face up in the direction of the child entering. 22. No one was hurt the first two times commuter train engineer John DeCurtis went past stop signals . 23. Current train-control systems can limit speeds or stop a train if an engineer ignores a stop signal . 24. The system stops trains in advance of any other train traffic, and before stop signals at interlockings. 25. The engineer had disregarded a stop signal . 26. A single signal may be equipped to function both as a stop signal and a distant signal. 27. At first, medical sources said that one of the train drivers overlooked a stop signal , causing the crash. 28. Actually, the diplomat exaggerated : There are no stop signals in the Serb capital and hardly any traffic. 29. Teachers should not keep track of the number of times they give out the GO and STOP signals . 30. Where signals are closely spaced, a stop signal and a distant signal can be mounted on the same post.
