Istanbul's motorways network are the O-1, O-2, O-3, O-4 and O-7.
By the end of 2019, the total length of Istanbul Province's toll motorways network (otoyollar) is 513 km and highways network (devlet yollari) is 327 km, totaling 840 km of expressway roads (minimum 2x2 lanes), excluding secondary roads and urban streets.
The density of expressway network is 15.7 km/100 km² (2019).
The O-1 forms the city's inner ring road, traversing the 15 July Martyrs (First Bosphorus) Bridge, and the O-2 is the city's outer ring road, crossing the Fatih Sultan Mehmet (Second Bosphorus) Bridge.
The O-2 continues west to Edirne and the O-4 continues east to Ankara.
The O-2, O-3, and O-4 are part of European route E80 (the Trans-European Motorway) between Portugal and the Iran–Turkey border.
In 2011, the first and second bridges on the Bosphorus carried 400,000 vehicles each day.
The O-7 or Kuzey Marmara Otoyolu, is a motorway that bypass Istanbul to the north.
The O-7 motorway from Kinali Gişeleri to Istanbul Park Service has 139 km, with 8 lanes (4x4).
The completed section of highway crosses the Bosphorus Strait via the Yavuz Sultan Selim (Third Bosphorus) Bridge, entered service on 26 August 2016.
The O-7 motorway connects Istanbul Atatürk Airport with Istanbul Airport.
Environmentalist groups worry that the third bridge will endanger the remaining green areas to the north of Istanbul.
Apart from the three Bosphorus Bridges, the dual-deck, 14.6-kilometer (9.1 mi) Eurasia Tunnel (which entered service on 20 December 2016) under the Bosphorus strait also provides road crossings for motor vehicles between the Asian and European sides of Turkey.

Istanbul's local public transportation system is a network of trams, funiculars, metro lines, buses, bus rapid transit, and ferries.
Fares across modes are integrated, using the contactless Istanbulkart, introduced in 2009, or the older Akbil electronic ticket device.
Trams in Istanbul date back to 1872, when they were horse-drawn, but even the first electrified trams were decommissioned in the 1960s.
Operated by Istanbul Electricity, Tramway, and Tunnel General Management (İETT), trams slowly returned to the city in the 1990s with the introduction of a nostalgic route and a faster modern tram line, which now carries 265,000 passengers each day.
The Tünel opened in 1875 as the world's second-oldest subterranean rail line (after London's Metropolitan Railway).
It still carries passengers between Karaköy and İstiklal Avenue along a steep 573-meter (1,880 ft) track; a more modern funicular between Taksim Square and Kabataş began running in 2006.

The Istanbul Metro comprises five lines (the M1, M2, M3 and M6 on the European side, and the M4 on the Asian side) with several other lines (such as the M5, M7, and M8) and extensions under construction.
The two sides of Istanbul's metro are connected under the Bosphorus by the Marmaray tunnel, inaugurated in 2013 as the first rail connection between Thrace and Anatolia, having 13.5 km length.
The Marmaray tunnel together with the suburban railways lines along the Sea of Marmara, is part of intercontinental commuter rail line in Istanbul, from Halkalı on the European side to Gebze on the Asian side.
Marmaray rail line has 76.6 km, and the full line opened on 12 March 2019.
Until then, buses provide transportation within and between the two-halves of the city, accommodating 2.2 million passenger trips each day.
The Metrobus, a form of bus rapid transit, crosses the Bosphorus Bridge, with dedicated lanes leading to its termini.
İDO (Istanbul Seabuses) runs a combination of all-passenger ferries and car-and-passenger ferries to ports on both sides of the Bosphorus, as far north as the Black Sea.
With additional destinations around the Sea of Marmara, İDO runs the largest municipal ferry operation in the world.
The city's main cruise ship terminal is the Port of Istanbul in Karaköy, with a capacity of 10,000 passengers per hour.
Most visitors enter Istanbul by air, but about half a million foreign tourists enter the city by sea each year.

International rail service
Istanbul's motorways network are the O-1, O-2, O-3, O-4 and O-7. By the end of 2019, the total length of Istanbul Province's toll motorways network (otoyollar) is 513 km and highways network (devlet yollari) is 327 km, totaling 840 km of expressway roads (minimum 2x2 lanes), excluding secondary roads and urban streets. The density of expressway network is 15.7 km/100 km² (2019). The O-1 forms the city's inner ring road, traversing the 15 July Martyrs (First Bosphorus) Bridge, and the O-2 is the city's outer ring road, crossing the Fatih Sultan Mehmet (Second Bosphorus) Bridge. The O-2 continues west to Edirne and the O-4 continues east to Ankara. The O-2, O-3, and O-4 are part of European route E80 (the Trans-European Motorway) between Portugal and the Iran–Turkey border. In 2011, the first and second bridges on the Bosphorus carried 400,000 vehicles each day. The O-7 or Kuzey Marmara Otoyolu, is a motorway that bypass Istanbul to the north. The O-7 motorway from Kinali Gişeleri to Istanbul Park Service has 139 km, with 8 lanes (4x4). The completed section of highway crosses the Bosphorus Strait via the Yavuz Sultan Selim (Third Bosphorus) Bridge, entered service on 26 August 2016. The O-7 motorway connects Istanbul Atatürk Airport with Istanbul Airport. Environmentalist groups worry that the third bridge will endanger the remaining green areas to the north of Istanbul. Apart from the three Bosphorus Bridges, the dual-deck, 14.6-kilometer (9.1 mi) Eurasia Tunnel (which entered service on 20 December 2016) under the Bosphorus strait also provides road crossings for motor vehicles between the Asian and European sides of Turkey.
Istanbul's local public transportation system is a network of trams, funiculars, metro lines, buses, bus rapid transit, and ferries. Fares across modes are integrated, using the contactless Istanbulkart, introduced in 2009, or the older Akbil electronic ticket device. Trams in Istanbul date back to 1872, when they were horse-drawn, but even the first electrified trams were decommissioned in the 1960s. Operated by Istanbul Electricity, Tramway, and Tunnel General Management (İETT), trams slowly returned to the city in the 1990s with the introduction of a nostalgic route and a faster modern tram line, which now carries 265,000 passengers each day. The Tünel opened in 1875 as the world's second-oldest subterranean rail line (after London's Metropolitan Railway). It still carries passengers between Karaköy and İstiklal Avenue along a steep 573-meter (1,880 ft) track; a more modern funicular between Taksim Square and Kabataş began running in 2006.
The Istanbul Metro comprises five lines (the M1, M2, M3 and M6 on the European side, and the M4 on the Asian side) with several other lines (such as the M5, M7, and M8) and extensions under construction. The two sides of Istanbul's metro are connected under the Bosphorus by the Marmaray tunnel, inaugurated in 2013 as the first rail connection between Thrace and Anatolia, having 13.5 km length. The Marmaray tunnel together with the suburban railways lines along the Sea of Marmara, is part of intercontinental commuter rail line in Istanbul, from Halkalı on the European side to Gebze on the Asian side. Marmaray rail line has 76.6 km, and the full line opened on 12 March 2019. Until then, buses provide transportation within and between the two-halves of the city, accommodating 2.2 million passenger trips each day. The Metrobus, a form of bus rapid transit, crosses the Bosphorus Bridge, with dedicated lanes leading to its termini. İDO (Istanbul Seabuses) runs a combination of all-passenger ferries and car-and-passenger ferries to ports on both sides of the Bosphorus, as far north as the Black Sea. With additional destinations around the Sea of Marmara, İDO runs the largest municipal ferry operation in the world. The city's main cruise ship terminal is the Port of Istanbul in Karaköy, with a capacity of 10,000 passengers per hour. Most visitors enter Istanbul by air, but about half a million foreign tourists enter the city by sea each year.
International rail service
Istanbul