Bids invited for upgradation of commuter rail system in Istanbul July 28, 2010 | Europe News The General Directorate of Railways, Harbours and Airport Construction (DLH – Demiryollar, Limanlar ve Hava Meydanlarý Ýnþaatý Genel Müdürlüðü), Turkey, has invited international competitive bids (und... This content is available to only subscribers. Username or E-mail Password Remember Me Forgot Password