General ways to travel: we always use the preposition “by.” We can travel by bike, by motorcycle, by car, by van, by lorry, by truck, by train, by plane, by bus, by ship, by tram, or by boat. They travelled to Australia by plane. (not a specific plane) We can also use by to refer to the transportation environment (by sea, by land, by air) or the surface area (by rail, by road, by water). I hate travelling by air! If we talk about specific transport vehicles and you must sit inside the vehicle, we use in. Some examples would be: "in a car", "in a truck", or "in a helicopter": it is not possible to stand in them. My dog goes to the vet in my car. If you can stand or walk on the vehicle… Other examples : on a plane, on a tram, on a ferry, on a subway, or on a train. - You can stand or walk on all of these, even when they are in motion. He goes to the disco on the bus. If we sit or stand upon the top of the vehicle, then we also are on it. So we go on a bicycle, on a surfboard, on a motorcycle, on a skateboard, on a horse, on a snowboard, on foot, etc. I usually goes to work on a horse.