The Hvaler Tunnel is a single-tube road tunnel ( underwater tunnel ) between the Norwegian islands Asmaløy and Kirkøy in the municipality of Hvaler in the province ( Fylke ) Viken . The tunnel along Fylkesvei 108 is 3751 meters long. The deepest point is around 120 meters below the sea surface. An automatic section control (SATK) is built into the tunnel . It measures the average speed of the vehicles.
Map with all coordinates: