A global multi-hazard risk analysis of road and railway infrastructure assets

TLDR

Transport infrastructure is exposed to natural hazards all around the world. The study presents the first global estimates of multi‑hazard exposure and risk to road and rail infrastructure. The authors compiled worldwide hazard data and infrastructure inventories to calculate exposure and risk. About 27 % of global road and rail assets face at least one hazard, with 7.5 % exposed to a 1/100‑year flood, generating $3.1–22 billion in annual damages—mostly from flooding—constituting ~0.02 % of global GDP but up to 1 % in some countries, and a cost‑benefit analysis indicates flood protection would yield positive returns for roughly 60 % of affected roads.

Abstract

Transport infrastructure is exposed to natural hazards all around the world. Here we present the first global estimates of multi-hazard exposure and risk to road and rail infrastructure. Results reveal that ~27% of all global road and railway assets are exposed to at least one hazard and ~7.5% of all assets are exposed to a 1/100 year flood event. Global Expected Annual Damages (EAD) due to direct damage to road and railway assets range from 3.1 to 22 billion US dollars, of which ~73% is caused by surface and river flooding. Global EAD are small relative to global GDP (~0.02%). However, in some countries EAD reach 0.5 to 1% of GDP annually, which is the same order of magnitude as national transport infrastructure budgets. A cost-benefit analysis suggests that increasing flood protection would have positive returns on ~60% of roads exposed to a 1/100 year flood event.