1. A rapid transit system is for electric multiple unit (EMU) trains running on exclusive right-of-way tracks in the crucial transportation corridors of a metropolitan area and can be constructed underground, elevated, or on ground level. With exclusive right-of-way, it runs without interference from any other traffic. Moreover, it operates automatically or via a semi-automatically controlled system and provides fast, punctual, safe, and comfortable service with dense headway and great transportation volume, known as a "mass rapid transit (MRT)" system. In general, the six prevailing modes of MRT adopted around the world are: Heavy Rail Rapid Transit, Light Rail Rapid Transit, Rubber-tyred Rapid Transit, Monorail Rapid Transit, Automated Guideway Transit and Magnetic Levitation Transit.

The factors taken into consideration when selecting which kind of MRT to adopt are:

2. To reach the average operating speed of 34 kph (including dwell time), DORTS' planning manual states that the high-capacity system's maximum train speed is 90 kph, the maximum operating speed is 80 kph, the medium-capacity system's maximum operating speed is 80 kph, and automatic operating speed is at least 70 kph.