Analysis of Polulion in Road Tunnel's and its Effect on Safety

One of the major challenges for the transportation system is transportation's effects on environment. The most important ones are the impacts on air quality, energy consumption and land use. Air pollution is considered as a matter of serious environmental pollution caused by transportation systems. There are problems for tunnel user's so that these kind of problems can cause and create a fire hazard, environmental effects such as global warming, ozone layer thickness reduction, reduced access to clean air, increase in density and toxic emissions from gasoline and choking, gathering dust and aerosols and decrease tunnel visibility, congestion and emissions from gasoline fires. These problems threaten mental health of tunnel users and affect tunnel traffic safety. In order to maintain an acceptable level of toxic gases and pollutants, the ventilation system needs to be designed in a way that is both economical and applicable in emergency. The tunnel’s ventilation is the most important safety measure and safety assessment of tunnels in design and improvement of the air-conditioning system. Therefore, strategies for obtaining fresh air to dilute pollutants is presented and there is an urgent need to calculate the flow rate of air. In this study, factors affecting tunnel ventilation are evaluated, so the classification of them into a number of indicators and sub-indicators can be done and in the end a tunnel safety index in ventilation will be presented.