Information on incidents in tunnels, as well as lessons drawn, have been addressed by various reports of the PIARC Committee on Road Tunnels. Earlier reports present a statistical census of breakdowns, collisions and fires in selected tunnels, as well as the lessons to be drawn from such events for the geometric design of the tunnel, the design of the safety equipment and the operating guidelines - thus presenting a collection of data of vital importance to engineers and decision-makers involved in tunnel design :
Well-structured and reliable information on tunnel incidents is of great importance, for instance as input data for quantitative risk assessment, or to motivate improvements in safety systems and procedures. These topics are addressed systematically in the new technical report 2016R35 “Experience with Significant Incidents in Road Tunnels”.
The incidents of Mont Blanc, Tauern and St. Gotthard (1999 and 2001) led to an increased awareness of the possible impact of incidents in tunnels. The likelihood of escalation of incidents into major events is low, however the consequences of such incidents can be severe in terms of victims, damage to the structure and impact on the transport economy.
|1978||Velsen (The Netherlands)||770 m||2||5 fatalities et 5 injured|
|1979||Nihonzaka (Japan)||2 km||2||7 fatalities et 2 injured|
|1980||Sakai (Japan)||460 m||2||5 fatalities et 5 injured|
|1982||Caldecott (USA)||1,1 km||3||7 fatalities et 2 injured|
|1983||Pecorile (near Genova, Italy)||660 m||2||9 fatalities et 22 injured|
|1996||Isola delle Femmine (Italy)||148 m||2||5 fatalities et 20 injured|
|1999||Mont-Blanc (France - Italy)||11,6 km||1||39 fatalities|
|1999||Tauern (Austria)||6,4 km||1||12 fatalities et 40 injured|
|2001||Gleinalm (Austria)||8,3 km||1||5 fatalities et 4 injured|
|2001||St. Gotthard (Switzerland)||16,9 km||1||11 fatalities|
|2006||Viamala (Switzerland)||750 m||1||9 fatalities et 6 injured
A more complete table can be found on Table 2.1 "Serious fires accidents in road tunnels" of report 05.16.B.
These catastrophes demonstrated the need for improving preparation for, as well as preventing and mitigating, tunnel incidents. This can be achieved by the provision of safe design criteria for new tunnels, as well as effective management and possible upgrading of in-service tunnels, and through improved information and better communications with tunnel users. Conclusions drawn from the enquiry following the Mont Blanc tunnel fire were that fatal consequences could be greatly reduced by:
A detailed description of the Mont Blanc, Tauern and St. Gotthard fires including the original configuration of the tunnels, and a step-by-step guide to the incident, fire progression, and the behaviour of operators, emergency services and users, as well as the lessons to be drawn can be found in Chapter 3 "Lessons learned from recent fires" of report 05.16.B : . The lessons learnt are summarised in Table 3.5 of this report. Similar information is given in Routes/Roads 324 "A comparative analysis of the Mont-Blanc, Tauern and Gotthard tunnel fires" (Oct. 2004) on p 24.
However, characteristic events are fortunately rare, and may be limited to specific circumstances. Hence a systematic analysis of less serve, but more frequent incidents (collisions and fires) may provide a more representative picutre of real tunnel incidents. Appendix 5 of the technical report “Experience with Significant Incidents in Road Tunnels” provides a survey of 32 real tunnel incidents, including a short description and important conclusions. Further, this report presents updated statistical data on tunnel collisions (Chapter 3) and fires (Chapter 4) for many countries. The data base used for the calculations are enclosed in Appendix 3 (collisions) and Appendix 4 (fires) respectively. Chapter 5 provides examples of interesting findings from information relating to real incidents.
After the fire of March 24th 1999, the Mont Blanc tunnel required significant renovation before it was able to be reopened to traffic. The ventilation system comprised a significant portion of the rehabilitation design work - a description of the dimensioning, automatic operation and full-scale fire tests can be found at Appendix 12.2 "The Mont Blanc Tunnel Renovation" of report 05.16.B.
See Appendix 8 "Austrian statistical study of 2005: Comparative Analysis of Safety in Tunnels, during 1999-2003 period" of report 2009 R08 for a contrast of traffic safety of road tunnels on motorways and expressways compared with safety on other types of roads, and also traffic safety in tunnels carrying bi-directional traffic with safety in tunnels with uni-directional traffic.