You're unfortunately either more vulnerable to other cars, less able to take action to avoid them or some combination of both. A motorcycle for example is nimbl

You're unfortunately either more vulnerable to other cars, less able to take action to avoid them or some combination of both. A motorcycle for example is nimble enough to attempt to avoid a collision but is more vulnerable if a collision occurs, while a bus might be sturdier/larger but your presence can't avoid a collision at all. As a group the safest option would be smaller vehicles, but individually each person is better off (in terms of safety during a collision) with something larger.