Why do we still build roads to fail in five years?

Drive along almost any major road in Britain and you will eventually encounter the same depressing sight, with freshly repaired potholes, temporary traffic management, roadworks and countless resurfacing projects. Add on sections of carriageway being rebuilt despite appearing relatively new and for many motorists, it raises an obvious question. Why do our roads seem to be in a constant state of repair and more importantly, why are we still building roads that require major maintenance so soon after completion? Writes John Ridgeway.

It is a provocative question and one that goes to the heart of how we design, fund and deliver infrastructure in the twenty-first century. The reality is that roads do not fail by accident, most road failures are entirely predictable.

The road building profession understands the causes. The materials are well researched. The loading conditions are broadly understood, but despite this knowledge, roads across the UK continue to deteriorate at a rate that frustrates motorists, burdens local authorities and creates significant long-term costs.

The question is not whether we know how to build longer-lasting roads. The question is why we so often choose not to.

The Cost of a Growing Problem

The scale of the challenge is considerable. According to the Asphalt Industry Alliance's Annual Local Authority Road Maintenance Survey, local roads across England and Wales face a maintenance backlog running into many billions of pounds. The 2024 survey estimated that local authorities would require more than £16 billion to bring roads up to their desired condition.

Perhaps even more concerning is the estimated timescale. At current levels of investment, some authorities reported it could take decades to address existing maintenance requirements. This is not just a pothole problem, it is an infrastructure problem.

Roads underpin economic activity, logistics, public transport, emergency services and daily life. When road networks deteriorate, the consequences extend far beyond inconvenience.

Roads Are Not Failing Because we Cannot Build Them

This is an important distinction. Modern highway engineering is extraordinarily sophisticated. Builders can design pavements capable of carrying immense traffic loads. Materials science continues to improve. New asphalt technologies, recycled materials and advanced modelling techniques have all contributed to better road construction.

The industry knows how to build roads that last. In fact, some roads built decades ago continue to perform exceptionally well. The challenge is rarely technical capability - it is economics.

The Lowest Cost is not Always the Lowest Cost

One of the greatest paradoxes in construction is that projects are frequently procured based on initial capital cost rather than whole-life value and roads are no exception. When budgets are constrained, there is often pressure to prioritise short-term affordability over long-term performance.

A road designed to last twenty-five or thirty years may require a greater upfront investment than one designed to meet minimum requirements. The result is a cycle that many infrastructure professionals recognise immediately.

A road is built, it performs adequately for a period, deterioration begins, maintenance is delayed, defects worsen and repair costs increase. The road eventually requires major intervention and when this happens the original saving disappears many times over. From a whole-life perspective, the cheaper option often becomes the more expensive one.

The Hidden Enemy Beneath The Surface

Most road failures are blamed on traffic. Heavy vehicles certainly play a significant role, but traffic is often only part of the story. Water remains one of the greatest threats to road performance. Once water penetrates the pavement structure, deterioration can accelerate rapidly.

Small cracks allow moisture to enter. Repeated freeze-thaw cycles expand defects. Traffic loading worsens the damage until eventually the visible failures appear. Potholes are not usually the problem, but they are the symptom.

The real problem often started months or even years earlier. This is one reason why preventative maintenance is so important. According to the UK's Transport Research Laboratory and numerous highway maintenance studies, early intervention can significantly reduce lifecycle costs compared with waiting for major defects to emerge.

Unfortunately, preventative maintenance rarely attracts the same attention as emergency repairs.

We Are Designing for Today's Traffic, Not Tomorrow's

Another challenge facing highway infrastructure is that traffic volumes continue to evolve. According to the UK Department for Transport, vehicle ownership and road usage have increased significantly over recent decades, while freight movements remain essential to economic activity. At the same time, vehicle characteristics are changing.

Electric vehicles are generally heavier than equivalent internal combustion vehicles due to battery weight. Heavy goods vehicle movements continue to place significant demands on strategic routes. Population growth creates additional pressure on urban infrastructure.

In many cases, roads originally designed decades ago are carrying traffic levels far beyond what their designers anticipated. The consequence is accelerated wear and increased maintenance requirements.

What Can We Learn from Victorian Engineers?

Interestingly, some of the most successful infrastructure projects in British history were built by engineers who thought very differently. Consider Joseph Bazalgette's London sewer network.

When designing the system in the nineteenth century, he deliberately built significantly more capacity than was immediately required. At the time, some criticised the approach. Today, that decision is celebrated as visionary.

Many modern infrastructure challenges stem from the opposite approach. We often build to meet today's demand rather than tomorrow's. The result is infrastructure that reaches capacity far sooner than anticipated. So, perhaps the lesson is not about roads at all, perhaps it is about long-term thinking.

The Case for Whole-Life Infrastructure

Increasingly, infrastructure professionals are advocating for a whole-life approach to investment decisions. Rather than asking - "What is the cheapest road we can build?" the question becomes - "What is the most valuable road over the next thirty years?"

The answer may involve:

• Better materials
• Improved drainage
• Enhanced maintenance strategies
• More resilient pavement designs
• Greater investment in preventative maintenance

The upfront costs may be higher, but the long-term costs are often lower. Most importantly, the user experience is significantly better.

Technology Is Not the Entire Solution

There is a tendency within infrastructure discussions to assume that new technology will solve every challenge, delivering smart roads, connected infrastructure, advanced materials and artificial intelligence.

These innovations undoubtedly have a role to play, however, many road failures occur because of issues that engineers have understood for generations such as drainage, maintenance, load management and long-term planning.

Sometimes the greatest improvements do not come from new technology. They come from applying existing knowledge more effectively.

The Bigger Question

Perhaps the real question is not why roads fail after five years – the real question is why we continue to accept it. The engineering knowledge exists, the materials exist and the expertise exists.

The evidence supporting whole-life infrastructure investment continues to grow, but short-term decision making often dominates infrastructure delivery. Roads are not just construction projects, they should be seen as long-term assets and like any asset, their performance depends largely on the decisions made at the beginning.

If we genuinely want more resilient infrastructure, fewer roadworks and better value for taxpayers, we may need to stop asking how cheaply we can build roads and start asking how long we want them to last.

Because the roads that deliver the greatest value are rarely the cheapest to build. They are the ones still performing long after everyone has forgotten who built them.