Motorcycles run basically the same coverages as autos. The major difference is the cost. Since most states have a limited riding season, the cost to insure a motorcycle is usually less expensive then a comparable automobile policy. Here in Texas, you can realistically ride a street bike 9-10 months out of the year and so the annual cost is reduced.
"Off road" vehicles are normally defined as "not street legal - can not be registered for use on public roads", i.e., 3 / 4-wheelers, dirt bikes, sand rails, golf carts. Some "off road" vehicles (dune buggies, enduro style dirt bikes) are can be made street legal and are rated differently from their "off road" counterparts.