Jan Husdal Trb 2005

The vulnerability of road networks in a cost-benefit perspective

Jan Husdal Molde University College 10 January 2005

Transportation Research Board Annual Meeting 2005 Washington, DC, 9-13 January 2005

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Outline Formalities Biographical note

The Background Early beginnings Problem statement Example/illustration

The Research Reliability and vulnerability Risk and vulnerability Project evaluation and vulnerability The cost of vulnerability and reliability

Application Recent research

Conclusion Future research 2

Early beginnings
 

    

   


          


           





   

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Problem statement I - issue Road networks are vulnerable to many (external) circumstances Additional costs incur when people, travellers or goods do not reach their destination in space or time as intended. Delays Diversions/detours Late delivery, non-delivery, early delivery Just-in-time Perishable goods

This is particularly an issue in sparse, non-congested, rural networks, networks vulnerability is here more an issue than reliability (travel time variability) because the network is so essential for access to community services for the local population and access to markets for the local businesses.

Vulnerability of a transport network

The network’s susceptibility to failure (disruption, degradation).

Reliability of a transport network

The probability that the network functions, or rather: does not fail to function.

Reliability = Benefit ---- Vulnerability = Cost What is the (expected) vulnerability cost of using a particular route (or link on a route)? 4

Problem statement II - purpose To add reliability and vulnerability to the current project evaluation procedures To evaluate the cost of remaining vulnerable or non-reliable against the assumed benefit of becoming less vulnerable or more reliable with the proposed project. To aggregate a vulnerability index for a road network These arguments should come in addition to the quantifiable costs and benefits of a project as prescribed by current evaluation methods - they may, however, be in opposition to the decision supported by traditional cost-benefit analysis.

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Example

The service area of the hospitals in Molde and Kristiansund, on the north-western coast of Norway, is marked by a number of potential vulnerabilities: F=Ferry, CW=Causeway, ST= Subsea Tunnel, T=Tunnel, M=Mountain Pass, B=Bridge

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Related research – RISIT (2002-2007) The transport sector in general has very limited experience with regard to risk based management Cost-benefit analyses and environmental impact analyses are being used, but risk analyses and risk acceptance criteria are not. Risk and vulnerability as a concept and as a management tool has no marked tradition among the Norwegian road authorities or amongst the international road authorities Aven et al. (2004) www.program.forskningsradet.no/risit/

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Reliability and Vulnerability Reliability describes the operability of the network under varying strenuous conditions (i.e. the ability to continue to function).

Vulnerability describes the non-operability of the network under varying strenuous conditions (i.e. the susceptibility to fail to function).

A reliable network exhibits a high degree of operability as expressed by serviceability, accessibility, and non-variability under most circumstances, due to the presence of redundancy, robustness, and resilience.

A vulnerable network exhibits a low degree of operability as expressed by non-serviceability, non-accessibility, and variability under certain circumstances, due to the lack of redundancy, robustness, and resilience.

Vulnerability = Non-Reliability (under said certain circumstances)

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Risk and Vulnerability R=CxP R = Risk C = Consequence P = Probability

R = V(ec) x P(ec) V = Vulnerability to the occurrence of an external circumstance (ec) or threat P = Probability of an external circumstance occurring

Risk matrix. The threshold indicates the risk acceptance level

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Project evaluation and Vulnerability Some of the elements that project evaluation procedures should take explicitly into account in order to incorporate considerations of vulnerability are the following:

The probability and impact of failure of a given network, link or route, given external circumstances or strenuous conditions

The probability of the external circumstances occurring The robustness of the system the probability that the system will continue to function even if a threat eventuates at a vulnerable point

The time and cost to repair the system

if the threat occurs and the system fails at its vulnerable point

The costs to the general economy of such a failure

goods and passengers not getting to their destinations, or getting there late, transportation carriers being forced to use expensive detours, etc.

The contribution of a given project to improving the robustness and hence reliability of the system

The degree of risk aversion that should be applied

in deciding what weight to place on the risk that has been identified (level of threat x level of vulnerability) 10

The cost of vulnerability

Vulnerability The societal costs of vulnerability versus reliability. A - current state, B – high investment (new road), C – low investment (upgrading existing road), D - optimum

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Recent research I Bottlenecks in freight transport by road Developing a multi-criteria approach in assessing non-monetary effects of nature-related bottlenecks

V=

CiIi

V = Vulnerability C = Category weight I = Impact score 12

Recent research II Case 1: Oppdal – Kristiansund (lower right to upper left)

Left: Original route Right: Detour + 2.5 hrs + 135km (75mi) Estimated cost of disruption: NOK 900,000/year for heavy vehicles ($ 150,000/year) Non-toll road diverted to toll road + ferry

Case 2: Dombås – Molde

(lower right to upper left)

Left: Original route Right: Detour + 1.5 hrs + 80km (50 mi) Estimated cost of disruption: NOK 80,000/year for heavy vehicles ($13,300/year) Toll road + ferry diverted to non-toll road

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Recent research III S=

wi ci

Rv70 Oppdal-Kristiansund: 0,2x4 + 0,3x5 + 0,1x2 + 0,1x2 + 0,1x2 + 0,1x3 = 3,2 non-toll > toll

E136/Rv64 Dombås-Molde: 0,2x5 + 0,3x4 + 0,1x2 + 0,1x2 + 0,1x1 + 0,1x2 = 2,9 toll > non-toll

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Future research To establish a practice-oriented methodology for aggregating a vulnerability index for a road network, network and the costs associated with various vulnerabilities. To find the vulnerability cost of transport on a particular route or link on a route. To find the vulnerability cost of location in relation to the neighbouring transport network.

How do transport-dependent entities adapt to transport-related uncertainties? uncertainties

Suppliers – producers – customers JIT, inventory, lead times, scheduling, routing etc. Stated preference surveys to establish values and weights Case studies of selected firms to determine the costs of uncertainties

Develop a multi-criteria evaluation of both monetary nonmonetary impacts of vulnerability 15

Thank You… Questions?

Source: www.avisa-hordaland.no 16

Examples of issues

Critical paths Availability of alternative routes Cost of rebuilding Closures and downtime Hazardous materials transport Traffic safety Operations and maintenance Emergency preparedness Presence and probability of hazards

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