Last week, Transport Ministry of Turkey unveiled the 3rd tunnel project to be constructed under Bosphorus after Marmaray and Avrasya tunnels.
According to project, the two sides of Istanbul will be connected by a 3-storey tunnel from a point between two Bosphorus bridges.
1st tunnel is Marmaray Tunnel with a rail connection. And second is the Avrasya Tunnel under construction where cars will pass through. The Big Istanbul Tunnel will be a combination of both, allowing both cars and metro system to use the tunnel.
The tunnel will have a diameter of 16.8m. The middle storey will be used by metro, and others will be used by cars. Length of tunnel is 6.5km. The deepest point will be 110m under sea level, and 45m under the bottom of Bosphorus.
The rail and road connections of the tunnel will be as follows:
The roads passing through tunnel will be connected to TEM highway in each side. In addition to big tunnel, 9.65 km long tunnels will be constructed for connections. The daily capacity will be 120k cars.
The metro that will use the tunnel is a new line to be constructed, Incirli-Sogutlucesme, which will mainly follow the metrobus line. This line is similar with the one Istanbul Municipality had mentioned last year. Due to overcapacity usage of metrobus, municipality told the need of a metro line going under metrobus line.
The metro line will go through underground except the overpassing of Golden Horn.
This rapid metro line is planned to run %25 faster than other metros. Metro cars will run along 31 km long line with 14 stations in 40 minutes. Metro line will be connected to nine other lines. Daily ridership will reach to 1.5 mn.
Goverment will not fund the project. Whole cost, USD 3.5 bn, is planned to be paid by contractor, which will operate the tunnel for a given time.
Picture: Transportation Ministry
Tomorrow: Will Big Istanbul Tunnel Help Traffic Congestion?