I have a better idea. Why don’t Uber distribute plastic cups with lids in all major cities, and then the passengers pee in the cup and submit their urine samples to the Uber driver? Then the driver collects the cups, runs a few quick lab tests and is back in a jiffy from the lab and can pick up the right passenger. No more hand waving, gesticulating, making a fool of oneself on the street.
Don’t you just love low tech :)