In a tunnel or parallel gallery, signing of emergency exits leading to the open air are usually obligatory. Two standardised panels should be installed in front of the emergency exit, one of them visible from the direction of traffic and the other in the opposite direction (see Fig 1).
It is usually obligatory to install distance markers to the emergency exits for pedestrians. Standardised panels should be used for this purpose. They are installed in pairs, parallel to the road direction, at intervals of about twenty meters (see Fig 2).