Preparing resilient transportation systems for heatwaves

This Issue Note presents a summary of the effects of heatwaves on transportation infrastructure and offers strategies for mitigation and adaptation. It is an essential guidance document for transportation practitioners, policy makers, and urban planners. Extreme heat events such as heatwaves are increasing in frequency and intensity as a result of climate change. Transportation infrastructure and users worldwide are already facing disruptions, ranging from road damage and rail buckling to drops in ridership, from heatwaves. By 2100, annual costs to the European transportation sector from heat could reach 12.2 billion dollars. Heatwaves also have a profound effect on transportation user behavior, leading to changes in travel patterns and mode choices. Key consequences of heatwaves involve infrastructure damage, service disruptions, safety risks, harm to the health of passengers and transport workers, and lost revenue as users opt for private automobile transport in place of excessively hot public transport experiences.

On roads, heat contributes to 90 percent of pavement deterioration, while rail buckling incidents may increase over 20 times in parts of Europe by 2050. Collision risks also escalate 1-3 percent per 1°C temperature rise because heat affects road conditions and driver cognition. Air transport faces runway damage and aircraft performance reductions require weight limits and flight cancellations. Public transit ridership drops during heatwaves, especially in marginalized areas, as people avoid discomfort. Key recommendations include assessing critical vulnerabilities, applying flexible adaptation pathways suited to uncertainty, advancing heat equity considerations, improving extreme heat governance, and following a phased roadmap to develop resilient systems. This Note outlines the work transportation agencies can do to prepare for the silent hazard of extreme heat: conducting baseline assessments, performing feasibility studies for tailored interventions, generating actionable data, creating heat resilience toolkits, and implementing adaptive inclusive policies and infrastructure. Overall, enhancing transportation sector resilience to accommodate rising heat requires recognizing regional disparities, spurring innovation, centering social equity, coordinating governance, and adopting context-specific combinations of physical and social strategies. A systemic approach that covers prediction, preparation, prevention, and recovery is essential to charting heat-resilient futures. This Issue Note provides an outline of that systematic approach.