1) All sorts of things can be "crosswalks". Double line down the centre of the highway, a row of parking lot spaces, island of lines in the middle of the road, the word Lane painted in the middle of the road, a rumble strip on the side of the road.
2) All sorts of things can be "buses", like trucks, RVs and even trains.
3) bicycles and motorbikes are pretty much interchangable.
4) Hill doesn't have to be a hill, anything with a skyline or some forest will do.
5) A boat can be a bicycle. A mailbox can be a parking meter.