For drivers everywhere, potholes are more than just a nuisance — they’re a hazard. They damage cars, cause accidents, disrupt traffic, and cost governments billions in repairs. But what if roads could fix themselves? A team of international researchers is turning that idea into reality with a novel self-healing asphalt that could transform the way we build and maintain roads.

It’s a blend of biology and modern cutting-edge technology. By embedding tiny plant spores filled with recycled oils into asphalt, scientists have created a material that can mend its own cracks. When the road surface is compressed by passing traffic, the spores release their oil, softening the bitumen and allowing it to flow back together. In lab tests, this self-healing asphalt repaired microcracks in less than an hour.

“When you close the cracks, you prevent potholes from forming in the future and extend the lifespan of the road,” said Dr. Jose Norambuena-Contreras, a researcher at Swansea University. “We can extend the surface lifespan by 30%.”

A 2021 survey from the American Automobile Association found that last year 1 in 10 drivers sustained vehicle damage significant enough to warrant a repair after hitting a pothole. With an average price tag of almost $600 per repair, damage caused by potholes cost drivers a staggering $26.5 billion in 2021 alone.

Self-filling cracks

Potholes begin as small cracks in the road surface due to the weight of traffic and bitumen’s natural hardening over time. Water seeps into these cracks, expanding and contracting with changing temperature. So, the gaps widen, traffic presses down and eventually this leads to potholes.

The researchers, working with teams from Swansea University, King’s College London, and Google Cloud, used machine learning to model how organic molecules in bitumen behave. The AI allowed them to simulate the self-healing process and optimize the material’s performance. “We are proud to be advancing the development of self-healing asphalt using biomass waste and artificial intelligence,” said Dr. Norambuena-Contreras.

The spores used in the asphalt are smaller than a strand of hair and are filled with recycled oils. When cracks form, the spores release their oil, softening the bitumen and allowing it to “stitch” itself back together. This not only prevents potholes but also reduces the need for frequent road maintenance, saving time and money.

Great potential but still much to study

The environmental benefits of self-healing asphalt are just as compelling as its practical ones. Traditional asphalt production is a significant source of carbon emissions. But the new material incorporates biomass waste, such as brown algae and recycled cooking oils, reducing reliance on petroleum-based products.

This doesn’t mean that this material is helping the environment; it’s just a bit less polluting. And just because there’s evidence the material can fill its cracks, performance in real-life scenarios is a whole different matter. What if this asphalt is less structurally stable and breaks down sooner than conventional roads? We don’t know yet because this is still very early research.

“Producing infrastructure materials from local resources like waste reduces dependence on petroleum availability,” said Dr. Francisco Martin-Martinez, a computational chemistry expert at King’s College London. “This helps areas of the world that have limited access to petroleum-based asphalt.”

While the material is still in development, its potential is enormous. The researchers believe it could be scaled up for use on British roads within a few years. If successful, it could not only save millions of British pounds in repair costs but also make roads more sustainable for generations to come.