The Cairo Metro opened in 1987 as a single, 29-kilometre section of line. Lines 2 and 3 were completed in 1996 and 2012 respectively.
A major upgrade is underway to extend existing lines and add new ones. The programmes overall cost is estimated at $12bn, and is being run by Egypts National Authority for Tunnels.
Current efforts centre on the Line 3 extension, which has been split into phases. Phases 1 and 2 are complete and phase 3 is under way. The $1.2bn main contract for phase 3 was awarded to a consortium led by Frances Vinci in April 2016.
A $377.5m contract to supply 256 metro cars was won by South Koreas Hyundai Rotem in February 2017. Phase 3 is due for completion by 2018.
Later this year, awards are due to be made for Line 4. A second section is scheduled to be tendered on this line from 2020.
There is no time frame for issuing tenders for lines 5 and 6; construction on the entire network is due to be finished by about 2050.
The expansion has suffered setbacks, including a tunnel boring machine becoming stuck in 2009, causing a tunnel to collapse.