Land vehicles travel along the same roads as pedestrians, except that they usually travel faster and can carry more. Not all land vehicles can travel on all roads. Some land vehicles will not function without vehicle engines, which must be built inside them after they are completed. New vehicles automatically come with a lock, which is locked (thus preventing people stealing your new vehicle!) When inside a land vehicle you cannot be attacked by animals. If you are travelling you can attack animals , if parked in a location you cannot attack animals. You can attack other characters from a land vehicle and also be attacked by them.
Boats can travel freely on water. They can generally travel faster than walking speed, and can carry more than an unaided person. Boats have prebuilt locks.You are safe from animal attack on the boat and cannot attack them. As with land vehicles people on boats can attack and be attacked by other persons outside the boat.
While in a vehicle, not everything happening outside is seen. Talking can always be heard, and you will notice if someone points at something. But you will not see people leaving or entering other buildings or vehicles, or a road.