I remember when I took the train, I would pass some small stations. Someone will plant two flags on the railway. One flag is red and the other is red. Why?

Take two flags during the day, one is green and the other is red. At night, he will bring a trolley bus, and he will shake it. His job is called assistant waiter, and we all call him: field service. His main job is to confirm whether the passing or arriving train has completely arrived at or passed the station, and whether there are any abnormal problems in each car body. When the train is running, the general driver can't see the rear of the vehicle, so every time he passes a station, a special person should visually check the condition of the vehicle so as to stop in time to deal with the problem. Generally, there is a stop at 10-20km, which ensures the safety of trains and reduces accidents.

Also, after passengers get on and off the passenger train, station attendant will give him instructions to drive, so he needs to confirm the vehicle status and contact the driver to drive.