Point #5 is "Check Wheel-to-Ground Reference".

What does this mean? It’s the relationship between the wheel of another car and an object on the road, usually the centerline or the edge of the road.

Think about a car that has just passed you in the next lane to your left. Or, think about a vehicle coming toward you on a two-lane road. Your first indication that the vehicle is coming into your lane may be seeing their wheels getting close to the lane dividing line or centerline. You may not be able to see their wheels actually turn - it’s almost imperceptible - but, you will see the wheels getting closer to the line or edge of the road.

Check this often so you can be prepared to take defensive action, if necessary. Keep a space cushion.