In August 2012 it was announced that the Saudi government had approved US$16.5 billion to build the four metro lines (182-kilometer (113 mi) long) of the system.

The announcement of government financing said that the expansion would take 10 years. Invitation for tenders were due to be issued in January 2013.

Four new lines are to be built. Work had been expected to commence construction in 2015:

  • Line  A : will connect Makkah to large multilevel parking facilities from the west to the south.
  • Line  B  : is a straight link between Mina and Makkah.
  • Line  C  : will connect Mina to the west side of Makkah through a big loop to the north.
  • Line  D  : circles Makkah with a straight extension to the north.

Work on the 188-kilometer (117 mi) long metro network is now expected to commence in 2016.

MMRTC has appointed Prasarana Malaysia to provide consultancy services during Phase 1, which covers the construction of two metro lines totalling 45·1 km and 22 stations by 2019.