How does the human brain calculate velocities? For example, when crossing a road and seeing a car coming towards you, how does the brain actually compute the rough velocity of the vehicle and your own maximum speed as you cross the road so as to judge that you can cross safely without using the relevant physics equations? I am interested particularly in the specific cognitive and/or neural processes and that level of detail rather than just the fact that the brain estimates distance and time taken to cross that distance. N.B. This question is derived from an earlier post of mine which I was advised to split into two for clarity. 
How does the brain calculate velocity?
cognitive psychology;perception;cognitive neuroscience;computational modeling;theoretical neuroscience