9. Operations, risk analysis and safety control

The above presupposes that the tunnels will fit in well with the surrounding environment, which is not always the case, and that sufficient space will be available, which is uncertain in the case of upgrades to existing tunnels whose civil engineering cannot be greatly modified.

Finally, tunnel operation, and in particular traffic monitoring and equipment control, are major elements of safety. For this reason, a second article will deal with these issues, including :

• how to improve an existing tunnel ;

• justification for the admission of dangerous goods traffic;

• operating conditions, including traffic regulations;

• accident, incident and fire response and rescue arrangements, including the definition of minimum operating...