As plastic pollution mounts worldwide and extreme heat continues to damage road infrastructure, engineers are turning to an unexpected solution: mixing recycled plastic into asphalt. New research and real-world trials suggest that plastic-infused roads could last longer, resist cracking under high temperatures and reduce the burden of plastic waste choking landfills and waterways.
Globally, more than 400 million tonnes of plastic are produced each year, yet less than 10% is recycled. Much of the remainder is burned, dumped or carried into rivers and oceans. At the same time, cities across hot regions are spending billions repairing roads damaged by heat, traffic and ageing materials. Researchers now say one problem could help solve the other.
Turning plastic waste into stronger roads
The idea is deceptively simple. Instead of discarding used plastic bags, bottles and packaging, small amounts of recycled plastic are blended into asphalt, partially replacing bitumen, the petroleum-based binder that holds road surfaces together.
In this process, plastic waste is cleaned, shredded into flakes and melted at high temperatures before being mixed thoroughly into asphalt. The plastic bonds with the material, leaving no loose fragments behind. Typically, about 8% to 10% of bitumen is replaced with recycled plastic.
Engineers compare the effect to adding steel reinforcement to concrete. The plastic improves flexibility and strength, helping roads better withstand heavy traffic and extreme heat. In hot climates, this means fewer cracks, potholes and surface deformations.
Real-world tests show promising results
Plastic-infused roads are no longer confined to laboratories. Test sections have been laid in parking lots and public roads, including a nearly one-mile stretch in Rockwall, Texas. Early observations indicate that these roads remain intact even when temperatures exceed 100 degrees Fahrenheit.
Similar results have been reported in South Asia. During an extreme heatwave in Bangladesh, plastic-infused roads showed no visible cracking, while nearby conventional roads suffered noticeable damage. Engineers say this improved heat resistance could be especially valuable as climate change increases the frequency and intensity of heatwaves worldwide.
Beyond durability, the approach also reduces the need for new petroleum-based materials by reusing plastic that already exists. For a single mile of one-lane road, several tonnes of plastic waste can be diverted from landfills.
Environmental benefits and lingering concerns
Supporters argue that plastic-infused asphalt addresses two major challenges at once: deteriorating road infrastructure and plastic pollution. Longer-lasting roads could mean fewer repairs, lower maintenance costs and reduced emissions from construction equipment.
However, challenges remain. Scaling up the technology requires a steady supply of clean, sorted plastic, something many cities currently lack. Not all plastics can be safely used, and improper processing could release harmful fumes during construction.
There are also concerns about microplastics tiny fragments that can be released as materials wear down over time. Researchers studying plastic-infused asphalt say early findings are reassuring. Tests suggest that microplastic release from these roads is extremely low and significantly less than the particles released by worn vehicle tyres. Long-term monitoring is ongoing to ensure environmental safety.
Engineers involved in the research say the next phase will focus on expanding trials to more regions, testing different plastic blends and refining standards to ensure safety and durability. Patent applications have already been filed, and there are plans to commercialise the technology in the coming years.
While plastic roads are not a complete solution to the global waste crisis, experts say they represent a practical step toward more sustainable infrastructure. As long as plastic waste remains abundant, turning it into longer-lasting roads could help keep at least some of it out of landfills and communities and under the wheels of progress instead.