Rail or bus transit service operating completely separate from all modes of transportation in an exclusive right-of-way.

Rail or motorbus transit service operating completely separate from all modes of transportation on an exclusive right-of-way.

A rapid transit, underground, subway, tube, elevated, or metro(politan) system is a railway—usually in an urban area—with a high capacity and frequency of service, and grade separation from other traffic. In England, such a system is called an "underground" while in most of North America and in Glasgow, Scotland it is a "subway". In most of the rest of the world it is called a "metro".