and the 13.6 km long Marmaray tunnel.
On the Asian side, construction of the 21.66 km (13.5 mi) long M2 line from Kadköy to Kartal continues, which will have a total of 16 stations.The Marmaray tunnel (Bosporus undersea railway tunnel) will connect the metro lines of the Asian and European parts of the city. According to the scheduled construction timeline, the tunnel will enter service in 2013.
Bus rapid transit (also known as metrobus or quality bus) is a useful public transportation system in Istanbul.
Osmanbey subway station.
Map of the Istanbul rail transit network. (Not including some of the Subway lines currently under construction).