Originally Posted by djk7

I drove a car rental shuttle for a few months back in my college days. My experience is that most people don't tip, the ones that did were usually the ones who needed help with luggage, but many of those didn't either. My feeling was that I didn't really expect tips, but was grateful when I got them. Some of the other guys were more aggressive almost standing there with their hands out.

I found people tended to tip better when the bus wasn't crowded, and especially if no other riders were around to see them tip.