Accessibility and a steady increase in ridership place new demands on the infrastructure of the city railway station Dortmund. Conversion and extension of the light rail system provide the sustainability safely.
The Henndorf bypass lead to a noticeable relief of traffic congestion. Centrepiece of the bypass is the double lane 2,150 meters long road tunnel, which is now used by approx. 20,000 vehicles per day.
The Roppen tunnel between Innsbruck and Landeck in Austria was made safer by the construction of the second tube. The 5,069 meter long tunnel was driven conventionally.