The Evaluation of Road Network Vulnerability in Mountainous Areas: A Case Study

Abstract

This paper deals with the issue of road network vulnerability, with special reference to a mountainous area case. It describes the implementation of a methodology that ranks links of a network according to their importance in maintaining a proper connectivity between all origin-destination pairs. Such a ranking can be particularly helpful in prioritising maintenance investments to be planned along the links of a road network.Following a conceptual approach observed in transport literature, we consider vulnerability to be connected to importance, i.e. a measure of the consequences of the collapse of a network element. In the present study we introduce a new definition of importance -with respect to a given link -that simultaneously includes two aspects: its level of usage, i.e. how many people typically use the link when travelling in a given time window, and the impact that the closure of that link could have on the general functionality of the network as a whole.The methodology proposed was implemented in order to obtain a ranking of importance for the links of a real-scale network, i.e. the road network of the Province of Bolzano, a highly mountainous area located in the Italian Alps.

Vulnerability and resilience of transport systems – A discussion of recent research

“…This is particularly relevant when comparing the disruption performance of road networks in sparsely versus densely populated areas. Rupi et al (2014) suggest an alternative way of generalising the concept of link importance that also serves the purpose of associating a cost to cut links. They first suggest that the importance of a link should have two components: the average daily traffic on the link if there are no disruptions (local importance) and the increase in total travel cost in the study area if the link is closed (global importance).…”

Extending natural hazard impacts: an assessment of landslide disruptions on a national road transportation network

“…Events that form isolated sub-networks and disconnect OD pairs are termed cut links. In the literature cut links are handled by introducing a measure for the proportion of unsatisfied demand [70,71], setting travel time delay equivalent to the disruption duration [25], or by not fully closing segments (e.g. reducing speed 99.9%) [36].…”

Estimating the risk related to networks: a methodology and an application on a road network

“…(Rupi et al, 2015). Usually, risk estimates related to networks, including road networks, due to landslides are obtained by overlapping hazard and consequence maps 5 (Ferlisi et al, 2012;Pellicani et al, 2017), and therefore, the indirect costs for specific hazard scenarios are not considered.…”