This report is a continuation of the one published by PIARC in 2008 on "Human Factors and road tunnel safety regarding users". It addresses two specific points raised in the conclusion of the 2008 report:

• "It is most important that motorists understand how to behave in tunnels, in critical situation"
• "In case of fire, tunnel users should be alerted by at least two different channels of communication".

This report describes human behavioural aspects when driving, and how to communicate information to tunnel users in normal, congested and critical situations. It then details the various systems that can be activated for real-time communication with users. It reviews how these devices can be used in cases of congestion, a serious incident and fire and how the activation of these systems and devices must be adapted to the changing circumstances of the event.