Public Address Voice Alarm system (PAVA)

Public address systems enable operators to inform tunnel users of an incident that requires evacuation. These systems include:

• Loudspeakers installed at fixed intervals along the tunnel, which enable operators to address users directly to give them information or to ask them to behave in a particular manner.
• Sirens installed at fixed intervals along the tunnel that emit a sound signal indicating a danger
• Sound beacons installed near emergency exits that help to indicate the location of the exit and inform users that they should use it to evacuate.

These systems are explained in more detail in PIARC report 2016R06EN: “Improving safety in road tunnels through real time communication with users” and in the appendix to this report which provides the results of an international survey on the use of loud speaker public address systems.