The drivers control their machines from outside the sealed arena.
The real rule is simple: the driver controls the heat, air-conditioner and radio.
Proportional control is how most drivers control the speed of a car.
The driver can control the amount of braking effort by admitting more or less air to the train pipe.
He also offers exercises designed to help drivers control their frustration over, say, being cut off by an aggressive driver.
The driver will control his speed via an adjustable governor, up to a limit set by the local road surface.
I do, however, agree that only the driver should control the brake pedal.
The driver controls the heating system with a switch.
But all of the power generated by a piston engine is useless if the driver can't control the car.
During the maneuver the driver controls only the brake.