Are you sure that Uber offers the ride to the closest (geographically) car? I've noticed that most of the time when I see close cars, they are not the ones that snag my ride, which can be frustrating when there are multiple cars 2 minutes away and the car that wins my business is 10+ minutes away (this has happened multiple times to me). The map doesn't seem like it understands one way streets, but it also doesn't seem to prioritize by geography either.