Back in 1987, Singapore introduced the Mass Rapid Transit (MRT), and in 1990, the system was completed. The system only had three lines, of which the Choa Chu Kang Line and the North Line were connected to form what we know today as the North-South Line.
The MRT consisted of 42 stations, connecting the island from the West, North, and East. The MRTs today still look about the same as they were then.
After good reaction to the new MRT lines, many more lines were built, for example the Woodlands Extension in 1996 and the Changi Airport Extension in 2002.
Since then, all new MRT lines were built underground to save land space and to prevent it from being an eyesore.
New lines like the North East Line and Circle line were planned and built in the years that followed. The North East Line, completed in 2003, is the world's first fully automatic driverless underground line. The Circle Line, to be completed in 2011, will be second when completed.
As Singapore's MRT progresses on, it would continually expand.