Building started on 9 October 1984. On the stretch between Brännkyrkagatan and Folkungagatan an earlier tunnel called Södergatan had been built in 1944 in a cut-and-cover trench. Between 1964–1966 it was extended 150 metres under Åso High School.
At the start of the 1980s the decision was taken to build a tunnel to alleviate the congestion south of Högbergsgatan, and then to rebuild the existing northern tunnel. Work finished on schedule in January 1991.
The tunnel is actually two tubes of 7.25 metres wide apiece, with each carrying two lanes of traffic. The height is 4.5 metres, with 110 metres of the length cut out of the rock and the rest being concrete lined.