What happens if you turn off a car engine when at its top speed? It’s extremely dangerous as all the controls stop working. The steering becomes stiff as the power assist mechanism stops working. The brakes still work for maybe one more push, after which, the pedal becomes stiff and does not depress any more. The car keeps rolling on momentum till it comes to a halt due to wind resistance or you hit something (accident).
If it is an automatic car and you did this when in drive mode, you cannot reignite the engine whilst in drive mode. You cannot put it in park either as this will damage some locking pins in the drive mechanism. With a cool mind you might remember to put it in NEUTRAL and start up the engine again and gain back full control.
Contributed by Pro PavanRaj Urs, Bangalore, ARPRO 3