at/behind the wheel

at the wheel

1. Literally, driving a vehicle (and thus sitting at the steering wheel). Don't worry, Katie's at the wheel, and she is very good at driving in the snow. I'm so excited to finally be at the wheel of my own car!
2. By extension, in charge; acting the leader (of something). Jack is at the wheel, so I know they'll get this project done on time!
See also: wheel

behind the wheel

1. Driving a vehicle (and thus literally sitting behind the steering wheel). Don't worry, Katie's behind the wheel, and she hasn't been drinking tonight. I'm so excited to finally be behind the wheel of my own car!
2. In charge. With Jim behind the wheel, I'm not sure this team will have the leadership it needs.
See also: behind, wheel
Farlex Dictionary of Idioms.

at the wheel

 
1. operating the wheel that turns a ship's rudder; at the helm. The cabin boy was at the wheel with the captain close by.
2. operating the steering wheel of a car. Bobby was at the wheel when the car went off the road.
See also: wheel
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

at the wheel

In command, in control. For example, Ann hated being told what to do; she wanted to be at the wheel by herself. The analogy here is to the steering wheel of an automobile or other vehicle, or the helm of a vessel. For a synonym, see at the helm.
See also: wheel
The American Heritage® Dictionary of Idioms by Christine Ammer.

at/behind the ˈwheel (of something)

driving a car: Who was at the wheel when the car crashed?
Wheel in this phrase refers to the steering wheel of a car.
See also: behind, wheel
Farlex Partner Idioms Dictionary
See also:
  • at the wheel
  • be at the wheel
  • behind the wheel
  • drive in
  • drive in(to)
  • drive into
  • drive-in
  • what (one) is driving at
  • what somebody is driving at
  • what someone is driving at