The system is also one of the world's longest. Overall, the system contains of routes, translating into of revenue track and a total of including non-revenue trackage. Of the system's routes or "services" (which usually share track or "lines" with other services), pass through Manhattan, the exceptions being the train, the Franklin Avenue Shuttle, and the Rockaway Park Shuttle. Large portions of the subway outside Manhattan are elevated, on embankments, or in open cuts, and a few stretches of track run at ground level. In total, 40% of track is above ground. Many lines and stations have both express and local services. These lines have three or four tracks. Normally, the outer two are used by local trains, while the inner one or two are used by express trains. Stations served by express trains are typically major transfer points or destinations.