On the way to work this morning, I saw someone driving on a flat tire. It looked like the wheel cover (over a steel wheel) had come off. The tire was really flat, and the bead had clearly separated from the rim. However, the driver kept on driving merrily along, while this thing is going whump whump whump. He's going about 25 MPH driving slowly, and there's no way he can't hear it if I can from a distance. It looked like the tire had been like this for a while as it was literally kind of wavy looking, and it also looked as if there was wheel contact with the road, although no sparks. I've driven slowly home less than a half mile, but with my blinkers on. I tried honking, but the driver seemed oblivious. I'm not sure if he knew or not. However, this car clearly needed a tow or at least a spare (it might have been a compact spare). There were people on the sidewalk staring at the car since it was so loud. Now what's the worst that could happen? I've driven on a flat tire to get home or to a safe place to change a tire or wait for a tow. However, that's always been where the bead is still secure on the wheel and the tire is between the pavement and the ground. I was thinking it could damage an axle or wheel bearings.