Road Tunnels: Emissions, Environment, Ventilation

Due to a steady tightening of emission laws for cars and changes in the risk assessment of a tunnel fire, some design data need constant updating. The Report of the PIARC Committee on Road Tunnels to the XXth World Road Congress, 1995 (20.05.B) reviews the art of tunnel ventilation over the last 15 years. In the present publication new design information and some references are given for dimensioning a longitudinal and a semi-transversal ventilation system.

Cross Section Geometry in Uni-directionnal Tunnels

Work on this report started in 1998 after studying literature on accidents in tunnels and national design guides. The goal 4 is to develop the principles for a safe and cost effective tunnel cross section taking into consideration signalling and traffic management requirements. This report mainly describes the arguments considered in various countries concerning the dimensions of the cross section that are essential for traffic in terms of capacity, congestion level and safety. Conclusions are drawn [...]

Pollution by Nitrogen Dioxide in Road Tunnels

This report has been prepared by the PIARC Committee on Road Tunnel Operation (C5) working group n° 2 devoted to Pollution, Ventilation and Environment. Awareness of the problem raised by nitrogen oxides in urban environment which came up following pollution phenomena (e.g. in London in 1952) has led to studies being carried out on the noxiousness of NO2, and to the measurement of existing levels in tunnels. Classically most ventilation control systems are based on CO measurements in tunnel. [...]

Fire and Smoke Control in Road Tunnels

Among the possible risks, vehicle fires give rise to particular concern because they are not very rare events and their consequences might be far larger underground than in the open if no appropriate measures were taken. Also the important and continuous decrease in vehicle pollutant emissions has led to determine ventilation equipment by smoke control considerations in case of fire. This report provides the complete state-of-the-art prepared by the working group on "Fire and Smoke Control" of [...]

Road Safety in Tunnels

Since 1992 the PIARC Technical Committee on Road Tunnel Operation (C5) (Working Group on Traffic and Geometry) has started a world-wide survey in order to update the data on road safety. In addition to the global information on road safety, the various members of the Group have been requested to produce special studies on various structures, to allow the detailed analysis of problems related to breakdowns, accidents and fires and to draw more valuable information on design and operation of tunnels [...]