Question

How does a
person looking in a rear view mirror of a car, estimate the distance and
approach speed of an approaching cyclist?

Answer 1

The mirror used is rear view cars are convex mirrors which means that the object appear to be more closer than actually they are.So estimation of the distance and approach speed of an approaching cyclist comes basically from experience. The positive point of using convex mirror is that the range of view adaptability increases! 

Answer 2

The mirror used is rear view cars are convex mirrors which means that the object appear to be more closer than actually they are.
So estimation of the distance and approach speed of an approaching cyclist comes basically from experience. 
The positive point of using convex mirror is that the range of view adaptibility increases!