Why are convex mirror preferred over plane mirrors as rear view mirrors?

A convex mirror always forms virtual, erect and diminished images irrespective of the distance of the object.

Since the image is diminished, it enables a driver to view a large area of the traffic behind him.

If we use a plane mirror, we do not get a good view of the traffic as the size of the image is the same as the size of the object.

This is the reason why convex mirrors are used as rear view mirrors in vehicles.