Otoyol 2, abbreviated as O-2, locally referred to as 2. Çevreyolu, is a motorway in Istanbul, Turkey that forms the outer ring road of the city connecting European and Asian parts via the Fatih Sultan Mehmet Bridge.

The Fatih Sultan Mehmet Bridge, also known as the Second Bosphorus Bridge, is a bridge in Istanbul, Turkey spanning the Bosphorus strait. When completed in 1988, it was the 5th-longest suspension bridge span in the world.