Engineering, Construction and Infrastructure Design Connecting Eurasia Tunnel and Supporting Buildings by GMW Mimarlik Ltd. Sti The Eurasia Road Tunnel will connect the continents of Europe and Asia when completed in 2017. Approximately 1 km long twin tunnels at each end converge into a 3.4 km long, 13.7 m diameter two-deck tunnel bored 25 m below the seabed. The main aim of the tunnel is to provide a calm, safe, well lit, contemporary and well-designed direct link between two continents accommodating up to 100,000 vehicles per day.