Limfjordstunnelen is a Danish motorway tunnel which connects the highway in eastern Aalborg with the highway east of Nørresundby. Opened 6 May 1969, it was the country’s first motorway tunnel. The tunnel measures 582 metres (1,909 ft) in length, and 27.4 metres (90 ft) in width. Limfjordstunnelen comprises a 6-lane motorway, which is part of the E45.

The tunnel consists of a 582 m long immersed tunnel, which continues north in a 207 m long ramp. To the south, the immersed tunnel merges into a 43 m long in-situ tunnel continues in a 156 m long ramp. The immersed tunnel consists of five segments, which are 102 m long, 28 m wide and 8.5 m high. Each segment weighs approximately 25,000 tons. The tunnel is divided into two pipes. Each pipe is 12 m wide.

The project consists of monitoring the movements of the junctions between the tunnel-segments and the junction to the tunnel portal. At all junctions Vibrating Wire Crackmeters is installed to monitor the movement in two directions between the segments. At each side of the junctions biaxial digital tiltmeters are installed to help determine which segment that is moving. All data is collected by OMNIAlog dataloggers.