Metro under construction, tramway under construction
A four line, 300 km metro is under construction in Doha. The system will include commuter lines, four light rail line (more like a metro as defined by western standards), and a people mover. A monorail system is planned to be the first to open, and wll carry passengers between Bahrain and Saudia Arabia. According to initial planning documents, the metro lines will be mostly underground, which could be a challenge for engineers due to the high water table.
Also under construction is an 11.5 km caternary free tramway which will serve western Doha. The line is expected to open in 2015. Kniwn as the Education City People Mover, the line is actually a tramway that moves people. Which is what most tramways do.
Already under construction is the New Doha Airport, complete with underground metro station.
A four line light metro system has also been approved for the nearby city of Lusail, which will link up with the Doha metro. The metro will span 30 km and have 44 stations, of which eight will be underground.
Also being considered is a 10 station underground people mover system that will connect the metro with the West Bay area. The project is currently frozen due to potential cost overruns.
Railway Technology page
Dohametro - transportation and other urban issues in Doha
Skyscraper City page
Lusail light rail project awarded
Integrated Rail Project