As early as 1986 Erik Reitzel
proposed a metro ring, low- price and easy to construct. The metro around
the centre of Copenhagen would follow the waterways, i.e. the lakes, the
canals, and the sea. This solution would offer many technical and economic
advantages compared to a traditionally bored solution.
ring line proposal was ten kilometres long, and ten stations were planned.
project could be built in stages with the possibility of future extension.