The level of vulnerability of road users is difficult to express because they can not get to know all the variables that directly and indirectly threaten all participants in a given situation. Regardless of the responsible behavior of individuals while driving, often these parties threatened on account of behavior and ways of driving other traffic participants or force majeure. Material equivalent aka consequences and endanger traffic accidents on the roads, even in tunnels that can have far more serious consequences because the tunnels govern special conditions of safety and conduct in case of emergency. The width and transparency roads give drivers the apparent safety and a sense of how the accident can be avoided technique and driving style, the conviction that there is always some space security that allows an escape from the incident, a very dangerous situation. One circumstance in traffic completely different, and that is driving through a tunnel. There are few drivers who when entering the tunnel do not think only of one thing, that as soon as possible from it and come out. Of course, all this for most drivers, but there are those who easily underestimate driving through the tunnel. There are a number of dangerous situations and real problems that drivers can happen in a tunnel, and there is nowhere left to run and should always be kept in mind that the tunnel is no ordinary road. That's why they are the consequences of such events, but the behaviors that led to them terrible. Potentially dangerous and harmless congestion in tunnels, faults on the vehicle, and that the dangerous driving, crashes or fires in tunnels and does not speak. In all these situations, the driver is required exceptional seriousness, composure and properly react to avoid unintended consequences (the force of the vehicle behind, in case of any problem or malfunction of the vehicle) or if it is already a tragedy occurred, to minimize the effects of which are the most serious one result of a fire in a tunnel. Terms of tunneling, ventilation systems during construction and operation, the procedure in the event of accidents and of a fire in the tunnels are completely different than on any other roads. In the Croatia and in the world, the construction of the tunnel, as well as the circulation and safety is considered especially important.