The first phase includes seven elevated and six underground stations estimated to cost $1.5 billion, built by two consortiums of local and Japanese companies. The target date for services to begin is the end of 2016.
The second phase of 8.1 kilometers (5 miles) northward is planned to be completed by 2018, two years ahead of initial target.
"Socialization for a new lifestyle of using mass transportation has to begin right now so that once it is completed, people have been prepared to flock into the MRT and leave their cars," said Widodo.
The project, funded through a loan from the Japan International Cooperation Agency, or JICA, has been planned since the 1980s, but its construction was hampered by political crises, red tape and funding disagreements.
The consortiums include Japanese companies Shimizu Corp., Obayashi Corp. and Sumitomo Mitsui Construction Co. along with Indonesian state-owned companies PT Wijaya Karya and PT Hutama Karya and private firm Jaya Konstruksi.