Marmaray is a rail transport project in Istanbul. It consists of the construction of an undersea rail tunnel under the Bosphorus strait as well as the modernization of suburban rail lines along the Sea of Marmara from Halkalı on the European side to Gebze on the Asian side. The procurement of new rolling stock for suburban passenger traffic is also part of the project. Construction started in 2004, with an initial target opening date of April 2009.[1] After multiple delays, the projected opening date (as of March 2013) is October 29, 2013.[2]