Why is the government strategy needed?

The UK is currently experiencing extremely variable climate patterns, and the country needs to adapt to the rising risk of floods and extreme heat. According to the National Assessment of Flood and Coastal Erosion Risk, 38% of roads and 37% of railways in England are currently at risk of flooding, rising to 46% and 54% respectively by 2050.

In terms of extreme heat issues, the adaptation strategy recognises that rails buckle in extreme temperatures. Although no figures are mentioned, there are additional climate-related strategies for rail, such as Network Rail's regional adaptation pathways, which identify climate risks and the locations where investment should be prioritised. Put simply, work is underway to tackle flooding and extreme heat risk for critical infrastructure.

Is ground movement the blind spot in the strategy?

So, what does this all mean for the underlying ground beneath the UK road and rail networks? The strategy doesn’t name ground movement as a risk, but asset owners and network operators should treat it as one all the same.

Ground that becomes saturated after prolonged rain or flooding can lose bearing capacity, increasing the risk of settlement beneath critical transport assets and supporting structures. Additionally, clay-rich soil shrinks in heat and drought then swells again when the wet weather returns. These processes are already happening beneath the road and rail networks, so a strategy that doesn’t look into what flooding and extreme heat do to the ground is missing part of the problem.

Why this matters for roads

Surface defects such as potholes, dips and depressions are often seen as a maintenance issue, simply wear and tear of the road. In some cases, however, they are signs of an underlying issue, which could be subsurface voids or eroding soils. Treating only the surface can result in repeated repairs in the same locations.

This can result in higher maintenance and lifecycle costs, and sudden ground failures can potentially lead to emergency closures. In July, a road in Brownhills in the West Midlands was forced to close following the discovery of a sinkhole. As well as traffic disruption, businesses in the area noted a 30% reduction in footfall. It’s a clear example of why underlying ground issues are worth addressing early.

Why this matters for rail

Ground movement or settlement can have a similar impact on the UK’s rail network. Issues such as differential settlement (where one section of ground sinks more than another) or sinkholes can cause railway tracks and surrounding structures to move unevenly. This can lead to costly repairs and significant disruption to passengers.

In June, the discovery of sinkholes near a railway bridge in south London led to train services being suspended between Purley and East Croydon. Commuters travelling to and from Gatwick Airport and Brighton were among those affected. Understanding what’s happening beneath the ground and addressing the underlying issues plays a key role in keeping services reliable and efficient.

Why climate change compounds the risk

Some of the most severe ground movement occurs when prolonged wet periods are followed by hot, dry weather. Saturated ground can weaken and settle, while clay-rich soils can subsequently shrink during drought conditions. As these weather extremes become more frequent, the resulting cyclical movement places additional stress on transport infrastructure. Planning for flooding or extreme heat events separately only addresses part of the problem. There’s a bigger risk when these events occur back-to-back.

The importance of ground assessment

Early intervention can reduce the risk of ground movement beneath critical assets and infrastructure networks, saving time, money and disruption further down the line if the ground does fail. As asset owners and operators develop climate resilience strategies, understanding and addressing ground conditions should form part of the wider rail and road infrastructure resilience conversation. Mainmark supports transport networks with assessment, monitoring and ground improvement solutions that help reduce long-term risk.

In the event that remediation is needed, non-invasive techniques such as resin injection can strengthen affected ground with minimal disruption to live infrastructure.

In short, asset owners and network operators have an opportunity to investigate ground conditions early on in their plans instead of treating them as an afterthought. To find out how Mainmark UK can support your infrastructure project, speak to an expert today.