The Government of Cambodia will develop an underground metro system instead of an elevated railway (skytrain) for Phnom Penh’s future mass transit system. 

The subway will connect the capital to the surrounding province of Kandal and construction is expected to cost around USD1.8 billion. Cambodia-based engineers and companies will be preferred for works on the line. The Ministry of Transport (MOT) is also inviting China-based companies to invest in the subway project.

Since 2007, multiple feasibility studies have been conducted for different transport systems, including sky trains, subways, light rail, and monorails. Most of these were undertaken by the Japan International Cooperation Agency (JICA) and the China Road and Bridge Corporation (CRBC).