Cabs pull over, look at you, and drive off if you aren't the right skin color. It happens all the time.

They assume black people live in poor or dangerous or remote neighborhoods.

The law about cabs being required to stop is totally moot. Cabs simply don't pull over if they don't want to.

Go find a black guy and try to hail a cab with him for a few days. The data will really shock you.