1. To steer one's vehicle to the side of the road
2. To cause to pull over
1. When you are driving and then move your vehicle to the side of the road, reduce your speed, and then stop, you pull over or pull your vehicle over.
2. When you are driving and a police officer signals you to move your vehicle to the side of the road, reduce your speed, and stop, the police officer pulls you over or pulls the vehicle over.