20 road tunnels Köln

Row of bridges

The Department for Bridges, Urban Railway Construction and Tunnel Construction for the city of Cologne commissioned KREBS+KIEFER to compile construction-specific overall safety concepts for the conversion of 20 tunnels. Some are both road and urban railway tunnels, others are crossed by almost 40,000 vehicles every day, and some of the constructions are over 100 years old. One tunnel crosses below a hotel complex. Some of the constructions in question are successive bridges that in total cover such a long stretch that incidents such as fires, breakdowns and accidents would have consequences similar to that of a tunnel.

For these numerous different and “untypical” tunnel constructions, KREBS+KIEFER developed a uniform and adaptable classification of the subsequent safety documentation. This means that, after compilation of the overall safety concept, chapters and passages can easily be added, expanded and replaced as it is further developed.


  • Safety documentation
  • Overall safety concept