HazMat transportation by heavy vehicles and road tunnels. A simplified modelling procedure to risk assessment and mitigation applied to an Italian case-study

There are various factors influencing the occurrence of road accidents, among which mechanical, environmental, behavioural, physical and road intrinsic descriptors may be mentioned. In facing the routing problem, a realistic evaluation of the frequency must take into account on one side inherent parameters and attributes of the road, on the other side factors correlated to traffic. A framework of general applicability is presented and applied to an Italian case-study in order to assess and evaluate the risk connected to dangerous goods transportation by heavy vehicles (HV). Possible restrictions and alternatives connected to re-routing are analyzed, considering in depth the risk for a possible tunnel alternative route. The problem of tunnel option and related accident scenarios for HV are discussed, so to select proper risk mitigation measures, inherent to heavy vehicle and to tunnel. Regarding the last issue, a novel analytical model for solving the ventilation design for both plane and sloping tunnels is presented.