2 ptsPTOfficial number: 7092
What enables the tram to drive backwards?

Explanation
Correct answer: The reverser.
The reverser is a crucial component of the control desk in the driver's cab, used to select the direction of travel. Switching it changes the polarity of the current supplying the traction motors, which reverses their direction of rotation. As a result, the tram can move backwards, and speed is controlled using the same controller as for forward travel.