Tehran Metro is a rapid transit system serving Tehran, the capital city of Iran. Four lines (lines 1, 2, 4 and 5) of the metro are operational while two lines (lines 3 and 7) are still under construction. The system is owned and operated by Tehran Urban and Suburban Railway.
Tehran's is one of the busiest metros in the Middle East and the cleanest in the world. During the third quarter of 2010, an average of 4m passengers a day used the metro network. It is estimated that 6m passengers will use the metro daily once the new lines become operational. The number of passengers using the metro has grown from 3.5m in 1999 to 4m a day in 2010.
The metro network is currently 120km long. Upon completion of all the lines, the system will reach a length of 430km.