analyses of road interventions have been focused on project-level benefits. For instance, Peru’s Supervisory Board for Investment in Public Transport Infrastructure (OSITAN) typically asks concessionaries and the Ministry of Transport (MTC) to submit economic analysis for each intervention for which they are seeking funding. The main metrics used to choose projects are financial indicators based on future traffic demand. But this project-centered approach misses the system-wide benefits of some interventions, particularly their impact on resilience.

So, to plan for a resilient road network, it is important to identify the critical links of a network whose rupture the economy cannot afford, and the alternatives available to planners and policy makers to reduce the risks associated with the disruption of those links. This papers aims to help governments solve these challenges. Building on the framework and concepts for accessibility and criticality by (BriceñoGarmendia et al., 2015), this paper proposes a methodology to set priorities within Peru’s road network, taking a system-wide approach, and to design robust interventions that may reduce its vulnerability, despite the uncertainties related to hazards and their impacts. Specifically, it helps answer two questions.

What are the most critical roads in the national network, and of these, which are the most exposed to natural disasters? The study finds that because of high traffic and agriculture exports – combined with exposure to floods, landslides, and storm surges – disruption risks could be especially high for three clusters of the Peruvian road network: Carretera Central near Lima, Piura in the north and a southern part of the Pan Americana road.

What are the most robust proactive interventions to reduce the disruption risks of these critical links? The most robust options to mitigate disruption risk vary by link. In Piura and Pan Americana, building a floodproof road is the most robust option in the face of the many uncertainties considered, since it is the most cost-efficient investment across a large number of scenarios. By contrast, for Carretera Central, building redundancy is the most robust option.

# 2. Methodology

This paper uses a network approach to evaluate the vulnerability of a subset of the Peruvian road system across a wide range of potential future conditions. Given the size and complexity of Peru’s national road network, a systematic assessment of each link is costly in terms of data needs and computational demands, and would not necessarily address decision makers’ need to prioritize interventions. Instead, carefully selected criticality criteria can help narrow a road network of tens of thousands of links down to several hundred meriting further analysis.

Accordingly, this study is split into two main parts. First, we built a Geographic Information System (GIS) model of the road network in Peru that captures the physical characteristics and cast aspects of the road, which we use to identify a set of critical links. Critical links are those of utmost importance for the performance of the overall network, which can be defined using different geopolitical, social, and economic criteria. The impact that an individual road (a network segment more generally) has on the aggregate accessibility of the country or region gives a sense of the relative importance of that individual road in the network or, in other words, of its criticality.

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