I don't know about other countries, but public transport buses in Australia don't have seat belts on them. Even as a kid, I remember wondering why there was such a fuss made around seat belts in cars when you couldn't use one if you wanted to on the bus.

It was funny, when I went to the Philippines for the first time, I got into a cab and was trying to put my seat belt on when everyone laughed and said "no no you don't need to do that" - and it ended up feeling super normal to not wear a seat belt there anyway.