I had a driver stop to get gas on their way to me. Another one was very close when they accepted the hail, but after several minutes after I expected them to arrive I checked the map and noted they stopped at a CVS.
It's been a while since I had this problem: many times I'd hail an uberx, it'd be accepted, and then I'd have to wait 8-10 minutes for the driver to leave their home. It was upsetting, and I think uber may have fixed it by now, but I had to remind myself it was still better than the experience I used to have when calling for a cab.
I live in Dallas, btw.