Metrorail is a heavy-rail system (similar rolling stock to the Washington DC Metro) that has a singe major line (with spurs, such as the line to and from the MIA intermodal center). All tracks and stations are above ground.

The limited area of route coverage means that your starting and ending points must be near a station to make full-time commuting feasible. The Metrorail stations in the downtown area mesh with the MetroMover (a robotic people-mover system somewhat similar to the CDGval), which brings passengers closer to many offices and hotels in the core downtown, Brickell and Performing Arts Center areas.

If you live in Eastern Broward or Palm Beach counties, it is feasible to take Tri-Rail south and change to Metrorail at the combined Tri-Rail Transfer station. You need to carefully check schedule times, and weekend service has less frequency. The time of a combined Tri-Rail / Metrorail commute is lengthened by the fact that the Tri-Rail tracks run near I-95 in the northern counties but must swerve several miles inland (westward, away from the ocean to reach the transfer station and ultimately MIA) (this is because Tri-Rail uses existing CSX freight tracks).