Heat Bends Rails, Softens Runways and Strands Cargo Ships

As extreme weather becomes more frequent and more intense, floods, heatwaves, droughts, wildfires and storms are increasingly disrupting roads, railways, airports and waterways. Roads closed in Germany during this summer's heatwaves; travel on Britain's railways has been repeatedly chaotic.

But climate change does not affect every form of transport in the same way, and understanding the differences matters for anyone deciding where to spend money on resilience.

Roads

Heavy rain floods streets and tunnels or triggers landslides, blocking routes and damaging bridges. Heat softens asphalt, expands concrete and deforms road signs. Smoke from wildfires and dust storms cuts visibility, turning an ordinary drive into a dangerous one.

The effects reach the people working on the network as well as the surface itself. In London, bus drivers are due to strike over working in hot weather, saying cab temperatures can exceed 40°C.

Flooding is only one of the pressures on road networks: heat softens asphalt and deforms signage, while wildfire smoke and dust cut visibility. Photograph: ET Tisomboon/Shutterstock

Railways

Railways are especially vulnerable to both flooding and extreme heat, and the failures tend to be dramatic.

In southern Germany in 2024, heavy rainfall triggered a landslide that derailed a high-speed train, while flooding caused widespread cancellations and delays. Heatwaves stranded passengers for hours on a train stuck in a tunnel at Birmingham in 2022 after extreme heat damaged overhead power lines; passengers described conditions as being "like a sauna." On a Paris–Brussels service the same year, temperatures reportedly reached about 45°C after the air conditioning failed, leaving hundreds trapped.

Steel track expands in heat and can buckle, which is why operators impose speed restrictions during hot spells — a rational response that also degrades the timetable across the network.

Aviation

High temperatures reduce aircraft performance, because hot air is less dense and gives wings less to work with. They can also damage the runway itself.

During the 2022 heatwave, London Luton airport temporarily closed after parts of its runway softened in record temperatures, forcing flights to divert. Storms flood coastal airports, and wildfire smoke caused hundreds of cancellations at Marseille in 2025.

Rivers and ports

Water transport faces a paradox: sometimes there is too much water, and sometimes not enough.

Heavy rain makes rivers unnavigable and floods port infrastructure. Drought does the opposite, leaving cargo ships stranded in shallow channels and forcing operators to load vessels below capacity — which raises the per-tonne cost of everything moving on that route.

The compound problem

The most severe disruptions occur when different forms of extreme weather combine.

During Storm Claudia in Wales in 2025, heavy rain arrived with strong winds: the rain caused flooding while the wind brought down trees and power lines, blocking routes and making them dangerous to use. Neither hazard alone would have produced that outcome.

This is the part that resilience planning tends to handle badly. Infrastructure is generally designed against single hazards with defined return periods — a flood of a given severity, a temperature of a given peak. Compound events fall outside that framework, and they are becoming more common.

Why it spreads

The result is more than cancelled journeys. When one part of the transport network fails, disruption propagates quickly across a country or a continent, affecting deliveries, businesses and daily life.

Modern logistics is built on tight coupling and low inventory, which converts a local, temporary physical failure into a distributed economic one within days. A softened runway or a buckled rail is a small engineering problem. The supply chain attached to it is not.