In many cities this is solved with the "Uber rank" system, where you simply get in the first car in line, give the driver a code, and then it loads up your journey. Fast and avoids any hassles with drivers rejecting your destination.
Wait, shit, that's amazing. How did they do that? I mean, not how did they write the code to match when given the code (obviously the driver should scan the rider's QR code), but how did Uber get laws changed to allow them to do this obvious reimplementation of a taxi stand when it's technically illegal under taxi laws.