In which of the following cases can you use the emergency switch-off of the engine?
Show the correct answer
Correct answer
C. While stopping the vehicle.
Explanation
In the photo you can see the dashboard of a bus, and an arrow points to a "STOP" switch - the emergency engine stop switch. You may use it when the vehicle is stopped - answer C.
The emergency engine stop switch is used to turn off the engine immediately, for example when smoke is coming out of the engine compartment or something is endangering people near the vehicle. Using it while driving is dangerous: when the engine is turned off, the power steering stops working and the compressor no longer refills the air in the braking system, so steering and braking a heavy bus becomes very difficult. That is why you do not use it on a bend (answer A), because it will be hard for you to keep your course, or on a downhill slope (answer B), because you may lose engine braking and the retarder, and the compressor stops refilling the air in the brakes. The Road Traffic Act requires a vehicle to allow reliable use of the steering and braking controls. The switch is intended for a situation when the bus is already standing still.
Legal basis: Art. 66 para. 1 point 1 and 5 of the Road Traffic Act (Prawo o ruchu drogowym)