What is the purpose of the drive lock circuit ("green line")?
Show the correct answer
Correct answer
B. It prevents the tram driving with open (half-open) doors.
Explanation
The question is about the drive lock circuit, called the "green line" ("zielona linia"). It prevents the tram from moving with open or not fully closed doors - answer B.
The drive lock circuit checks whether all the doors are closed. As long as even one door stays open, the tram will not move off, which protects passengers from falling out or being caught in the doors when the tram moves off. The circuit does not detect trams on the track coming from the opposite direction (answer A) and does not allow passengers to open the doors before the tram stops (answer C) - its job is to make sure that the tram does not move off with doors that are not closed. Switching off the lock while driving with passengers is prohibited, and a fault in it must be reported to the technical service.
Legal basis: Art. 3 para. 1 of the Road Traffic Act (Prawo o ruchu drogowym)