Feedback from operation and incidents

The collection of data regarding incidents and accidents and their analysis is essential both for the evaluation of the operation criteria and for the assessment of risks in the tunnel. All of this is important with a view to a continuous improvement in tunnel safety. In particular, the collected data enable the frequency of events to be evaluated. Data also provide feedback regarding the consequences of events and also the  effectiveness of safety measures and equipment. They also provide additional information on the real behaviour of tunnel users.

The collection and analysis of data regarding incidents and accidents should allow the following two objectives to be achieved:

• At a local level (i.e. at the level of each single tunnel): they form an important basis for the definition and evaluation of improvements, to be decided by the owner of the tunnel. They are also a decision-making aid for the general improvement of safety in a given road network;
• At a national and international level: they form the key basis for the reference framework allowing authorities to formulate and adapt the general policies related to tunnel safety. In particular, they allow an assessment of the magnitude (in terms of frequency and severity) of critical events that can cause a danger to the life of users. They also allow the efficacy of safety installations to be measured and in certain cases, a comparison of the level of safety in a given tunnel with national or international safety data.

Lastly, they provide information (national statistics according to the type of tunnel) that is useful for the analysis of risks relating tunnels that are in project stage (ie. in development) or tunnels under operation that do not yet have an adequate database.

The lessons drawn from the operation, particularly during incidents and accidents, should be analysed. In fact if the results of these analyses reveal deficiencies, there is an opportunity to intervene by improving strategies and/or operating instructions.

The Chapter 3 "Collection and analysis of data on road tunnel incidents" of Technical Report 2009R08 defines in detail the conditions for analysing data from incidents and/or accidents.