otoyols in a province: 5 routes: Istanbul Province, O-1, O-2, O-3, O-4, and O-7. 5 routes: İzmir Province, O-5, O-30, O-31, O-32, and O-33. Most provinces served by an otoyol: 8 provinces served by the O-21: Ankara, Konya, Aksaray, Kırşehir, Nevşehir, Niğde, Adana, Mersin 6 provinces served by the O-4: Istanbul, Kocaeli, Sakarya, Düzce, Bolu, Ankara 6 provinces served by the O-5: Kocaeli, Yalova, Bursa, Balıkesir, Manisa, İzmir 5 provinces served by the O-52: Adana, Osmaniye, Kahramanmaraş, Gaziantep, Şanlıurfa Gallery See also List of motorway tunnels in Turkey Turkish State Highway System List of highways in Turkey List of longest highways Turkey, 2nd & 7th List of controlled-access highway systems Transport in Turkey Roads in Turkey References Turkey Highways Turkey transport-related lists