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Incorrect!

You're driving an articulated lorry. What could happen if you change to a lower gear while you're going too fast?

The vehicle could jack-knife
Correct answer
The engine could stall
The brakes could fail
The trailer could uncouple
You selected this answer

DVSA theory test explanation

Severe braking or selecting a gear too low for your road speed can cause the tractor unit to slow more quickly than the trailer. The trailer can then pivot around the coupling (fifth wheel), causing the vehicle to jack-knife. Jack-knifing is more likely to occur with an unladen vehicle, particularly on a bend or curve.

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