Wiktionary
at the wheel
prep.phr. 1 (context idiomatic English) driving; in control of a vehicle. 2 (context idiomatic English) In control of the situation; in charge.
Usage examples of "at the wheel".
The tall bony one had already disappeared, and presumbly he was at the wheel, for the engine roared up even before the door slammed, and the car leapt away with a grind of spinning tires that would have made any normal war-time motorist wince.