TRA I CRITERI GUIDA NELL'ASSUMERE DECISIONI NELLA GESTIONE DEL RISCHIO, NEI CASI DI ADEGUAMENTO DELLE GALLERIE STRADALI, IL DECRETO LEGISLATIVO 264/2006 INDICA ANCHE L'ANALISI COSTI-BENEFICI. DI SEGUITO UN APPROFONDIMENTO DELLA QUESTIONE SVILUPPATA CONFRONTANDO IL DETTATO NORMATIVO CON LE RECENTI "LINEE GUIDA PER LA VALUTAZIONE DEGLI INVESTIMENTI IN OPERE PUBBLICHE" NEI SETTORI DI COMPETENZA DEL MINISTERO DELLE INFRASTRUTTURE E DEI TRASPORTI DEL 1° GIUGNO 2017.
The paper illustrates and describes the structure of a new quantitative model of risk analysis for road tunnels named TRAM (Tunnel Risk Analysis Model). The result of the model, in accordance with the European Directive and the Italian Legislative Decree, returns the F-N curves of societal risk, in other words functions that relate the frequency of occurrence of an accidental scenario (F) with the expected consequences in terms of potential victims (N). Starting from two types of initial events, a fire and a Dangerous Goods (DG) release, a total of 18 accidental scenarios was defined. The frequencies of occurrence of each accidental scenario is obtained using the Event Tree Analysis (ETA) technique. For each scenario, the number of fatalities, expressed in terms of deaths, is obtained by simulating the formation dynamics of the queue of vehicles, using a model able to calculate the queue length, depending on traffic, the vehicle type, as well as the closure time of the tunnel. Then, a distribution model of the potentially exposed users has been defined and coupled with an egress model. The users' tenability is estimated on the basis of the egress model and the evolution of each accidental scenario, which is evaluated using a zone model. The proposed model can simulate each of the 18 accidental scenarios in several different positions along the tunnel, considering the impact that different tunnel infrastructure measures, equipment and management procedures can have on the users egress and on the propagation of the effects of the accidental scenarios. The model is able to consider the interdependence between these measures and their reliability in terms of their availability in an emergency situation. Finally, to validate the model, comparisons are made with the QRAM software developed by PIARC for some representative case studies. Through this model, it is possible to perform the risk analysis of a tunnel in an actual configuration and compare the expected value of damage with the corresponding one of the tunnel ...
In Europe, urban areas represent the "engine" of economic growth and employment in a territory: about 85% of the EU's GDP (gross domestic product) is generated in european cities. Several European cities, due to the extensive economic activities in urban areas, have to deal with and manage issues related to or caused by transport and mobility such as congestion, air pollution, safety and noise pollution. In 2010, for example, about 73% of European citizens lived in urban areas; this percentage is estimated to increase to more than 80% by 2050. In addition to the direct impact generated by traffic, urban mobility can also influence social development, social exclusion, and accessibility for people with reduced mobility. Consequently, the need to adopt sustainable transport systems is now a global goal that can no longer be postponed. To promote sustainable mobility models, current planning strategies have used smart growth interventions to move from mono-centric city structures to poly-centric, more localized configurations. For example, the idea of the 15-minute city is gradually growing in importance from both a policy and social perspective. The basis of the idea is the promotion of interventions to increase the supply of local services, such as schools, public transportation systems, health care facilities, dining facilities, jobs, recreation areas, and retail stores. In this way, local areas are created that are sustainable, inclusive, and walkable within a small radius on foot or by bicycle. Starting from these considerations, the aim of this work is to apply the idea of the city in 15 min to railway stations: in this perspective, the railway station becomes the starting point of the analysis as it represents the "door of the house", from where users start their last mile trips after getting off the train. For some railway stations located in Northern Italy, an analytical index has been defined that summarizes the characteristics of the station in relation to the territory in which it is located. In this way, it is possible to classify the stations on the one hand and, on the other, to identify and propose improvements aimed at relaunching the role of a railway station in a territory.
