1 Developing a Methodology for Road Network Vulnerability Analysis Erik Jenelius Div. of Transport and Location Analysis Dept. of Transport and Economics Royal Institute of Technology (KTH), Stockholm Nectar Cluster 1 Seminar, 12 th – 13 th May 2006, Molde University College

2 Summary Description of new project “Vulnerability Analyses of Road Networks” - Problem - Aim - Method Review of pilot study (Jenelius et al, 2006) - Concepts - Application examples

3 Why study road network vulnerability? Welfare of citizens Development and competitiveness of industry Efficient commuting Efficient logistics (just-in-time) Regional development Infrastructure repairs … Which roads are particularly important? Which regions are particularly exposed?

4 New Project: Aims Develop indicators of vulnerability and methods by which the effects of various actions could be assessed Develop tools to describe the functioning of the road system for the communication with the business community, regional representatives and different groups of users Connect to cost-benefit analysis so that it will be possible to analyse how the vulnerability could be reduced given limited budget for investments, operations and maintenance.

5 Method Primarily develop ideas from previous pilot study (Jenelius et al, 2006) Develop a new modelling tool - increase speed - include possibilities to handle scenarios (storms, floods, …) - integrate with GIS for visualization and scenario building In case of available data and time: - model and estimate weakness of links from historical incident data

6 Desired outcomes Perform study for the whole Swedish road network Study sub-network that complies with certain bearing capacity Study specific group such as timber transports Scenario models: - thaw, floods, extreme weather, accidents, …

7 What is vulnerability? “A susceptibility to incidents that can result in considerable reductions in road network serviceability” (Berdica, 2002) Vulnerability contains probability and consequences (exposure) Possible vulnerability measures: P(Q > q) : probability that consequences Q above threshold q (Holmgren, 2006) E(Q) : expected consequences …

8 Consequences: Importance and exposure The weakness of a link is the probability of a failure The importance of a link are the consequences of failure The criticality is a combination of weakness and importance The exposure of a region to a certain harmful event is the consequences of that event for that region Link k important to region R  Region R exposed to failure of link k

9 Measuring importance and exposure Measured as: increased generalised travel cost + unsatisfied demand Other possible measures: decreased potential accessibility …

10 Global link importance for the whole network E4 European highway Most important link in High Coast region

11 Demand weighted link importance for the whole network Short city roads, E4 Local and regional traffic Most important link in Gävle

12 Unsatisfied demand related link importance for the whole network Roads near the coast Boundary effects Most important link in Gävle Sensitive measure

13 Worst-case scenario: most important link closed Demand-weighted municipality exposure Local density important Northwestern parts the most exposed

14 Worst-case scenario: most important link closed Unsatisfied demand-related municipality exposure Northwestern region highly exposed Middle region unexposed