They may make minor repairs to air-hoses and couplers. In case of unexpected stops, the crew sets up signals to protect both ends of the train. Subway and streetcar operators. Subway operators control trains that transport passengers throughout a city and its suburbs. The trains run on tracks in underground tunnels, on the surface or elevated above streets.
Operators start, slow, or stop the train.
They make announcements to riders, open and close the doors, and ensure that passengers get on and off the subway safely. Operators should have a basic understanding of the operating system and be able to recognize common equipment problems and the signaling systems used by the trains. When breakdowns or emergencies occur, operators contact their dispatcher or supervisor and may have to evacuate cars. To meet predetermined schedules, operators must control the train's speed and the amount of time spent at each station. Increasingly, however, these functions are controlled by computers and not by the operator.