It can. It doesn't always. If the driver behind you is not particularly well aligned in the lane it can be difficult. Doubly so if it is a larger vehicle, relat

It can. It doesn't always. If the driver behind you is not particularly well aligned in the lane it can be difficult. Doubly so if it is a larger vehicle, relative to you. (I drive a small sedan, for example.) Imagine you are centered in the leftmost lane. The driver behind you is tailgating and riding close to the dashed lane divider to your right. You'd like to see down that very lane divider, to see an oncoming motorcycle. Your rear-view is going to be obstructed by the vehicle behind you. Particularly, the right side of the view, since the trailing vehicle is to the right of your center. You side view is also going to be obstructed, as the trailing vehicle will obscure the LoS going straight back along the dashed line. I'm able to see the dashed line, but only for a small distance; often only 0.5 to 1 seconds of travel distance. This isn't really sufficient, safety wise.