Risk Analysis for Road Tunnels

The recent catastrophes in the Mont Blanc tunnel, the Tauern tunnel and Gotthard tunnel have demonstrated the urgent need for improving the prevention and mitigation of tunnel accidents, including adequate detection systems and preparedness of operation staff and emergency services. This can be achieved by providing safe design and construction criteria for new tunnels, re-organising the management and the configuration of in-service tunnels, providing management with proper decision support safety tools, following-up the state of safety in tunnels and ensuring information and better communications with tunnel users. The numerous initiatives, which have taken place at the national, European and international levels, have led to different regulatory developments. The European Directive 2004/54/EC (the "EU Directive") is today a major legislative text for EU countries setting basic requirements for tunnels in the Trans-European Road Network (TERN). On the one hand, the EU Directive is a prescriptive guideline, defining a set of minimum requirements for the safe design, equipment and operation of road tunnels; on the other hand in some contexts the EU Directive requires decisions, based upon the results of a risk analysis; in article 13 the EU Directive obliges its Member States to "ensure, that at national level, a detailed and well defined methodology corresponding to the best available practices, is used ...". Furthermore, for tunnel safety experts this definition raises more questions than it can provide answers. A short glance at the theme already reveals that risk analysis is anything but an easily understandable and clearly defined subject; and there is a certain amount of scepticism about this tool as well, both among tunnel experts and operators, authorities and emergency services. In view of this situation, the Technical Committee 3.3 "Road Tunnel Operation" of PIARC set up a working group in 2005 to investigate strategies, tools and best practice for the management of road tunnel safety. The Technical Committee 3.3 identifies, develops and disseminates best tunnel safety management practice and gives better access to international information with regard to tunnel safety. One of the themes in the strategy of PIARC is the improvement of safety assessments, mechanisms, design and procedures consistent with efficient and effective operations that meet the needs of road users and their safety. One of the goals is to improve the safe and efficient use of the road system, taking into account road structures such as tunnels, including the movement of people and goods on the road network, while effectively managing the risks associated with road transport operations and the natural environment. Among other objectives the work of Working Group 2 focussed on risk analysis, aiming at describing the use of risk analysis for the investigation of safety issues in road tunnels and identifying the options and benefits of using this tool. The work on risk analysis was coordinated by Bernhard Kohl of ILF Consulting Engineers, Austria. The PIARC activities on this subject took up the results of major European research activities - mainly SafeT - and additional contributions prepared by the members of the working group resulting in a report entitled "Risk Analysis for Road Tunnels". For the covering abstract see ITRD E139491.