if you mean publick transportation, that's cause their usually cheaper. But having own car or boat or even an airplane is faster, and has more comfort. And of course, if your too fat to fit trough...
1.it reduces the distance that also save the oil. 2.through sea transportation we can transport huge amount of things easily.3.there is not more traffic in the sea in comparison to road.
Air transportation is very fast and can go essentially anywhere, without requiing roads as cars do, or docking facilities as boats to, or train tracks as trains do; planes do require some kind of...
advantages: faster closed area, protection from cold, rainy weather (as opposed to riding on camels/horses etc) disadvantages: pollution high cost of insurance, road tax, the car (mode of transport)...