In 2026, Texas engineers mixed 4.5 tons of waste plastic into nearly a mile of road; the recycled material replaced 8% to 10% of petroleum-based bitumen

Plastic is accumulating far faster than recycling systems can process it. Over 400 million tonnes of plastic are produced worldwide each year, and only about 9% of it is recycled; the rest is landfilled, incinerated or released into the environment. According to US statistics, landfills accepted about 27 million tons of plastic waste in 2018, which is almost one-fifth of all municipal solid waste that was produced in that year. The problem with roads is quite different; however, the two issues share a common link: asphalt, which is bound together by bitumen, a fossil‑fuel derivative. The asphalt on roads in hot states such as Texas cracks and ruts in high heat.

Rockwall's one-lane pilot replaced 8% to 10% of its Bitumen with plastic flakes

The team headed by Dr. Sahadat Hossain from UTA created a one‑lane paved strip on State Highway 205 in Rockwall, a suburb of Dallas, utilizing around 4.5 tons of recycled plastics to pave almost a mile of highway. In a Conversation article, Hossain said the plastic is cleaned, shredded into flakes and added to hot asphalt so it melts and blends in. The process replaces about 8% to 10% of the traditional asphalt binder and reduces demand for petroleum-based material while preserving the road's basic performance characteristics. Hossain compares the inclusion of plastic in the asphalt mix to the role of rebar in reinforced concrete, a comparison he lays out in 'Infusing asphalt with plastic could help roads last longer and resist cracking under heat.' The comparison matters in Texas because pavement temperatures can exceed 100°F in summer.


The pavement has held up through days exceeding 100°F so far

For now, the Rockwall project is a pilot rather than a final conclusion. Hossain, his colleagues and Texas Department of Transportation researchers are monitoring the road under real traffic and heat. According to a UTA news release, the plastic mix has not deteriorated on days when temperatures exceed 100°F in Rockwall and at earlier UTA test sites. Early data suggest the method could extend pavement life by a few years, reducing repairs and costs for the road authority. The researchers are also working through scale-up challenges, including access to enough clean, sorted plastic and the risk of microplastic shedding. Early data suggest that the risk of microplastic shedding from such pavement is likely low, because the plastic is largely integrated into the asphalt structure; a 2024 study in Resources, Conservation & Recycling estimated that microplastic release from plastic‑modified asphalt could be about three orders of magnitude (roughly 1,000 times) lower than rubber particles from worn tires, though the authors note that some release is still possible and may vary with mix design and traffic.

A 2024 Indian lab study found a 171% stiffness gain with 3% LDPE

The Rockwall pavement is a field pilot; however, the basic concept of using waste plastic material partially as a substitute for bitumen in the pavement mixture has also been examined scientifically elsewhere, in both laboratory and full-scale pavement testing. In the paper titled ‘Mechanical and Economical Feasibility of LDPE Waste‑Modified Asphalt Mixtures: Pathway to Sustainable Road Construction’ published in Scientific Reports, post‑consumer low‑density polyethylene was incorporated into a standard Indian bitumen grade at a 3% ratio and compared with four commonly used binders. According to the article, LDPE-modified asphalt increased pavement stiffness by 171% at 25°C and 125% at 35°C compared with the VG 30 binder, while indirect tensile strength rose by 51%.

The researchers in India not only tested the material in the lab but also evaluated it in a full-scale pavement system, finding a 57% increase in fatigue life and a 42.33% increase in rutting resistance compared with binders such as VG 30 and VG 40. Environmentally, the plastic-modified binder can recycle 750 kg of plastic waste per kilometer of single-lane pavement with a 50 mm surface course and its construction cost is comparable to VG 40 binder and 10% lower than PMB.

UTA has filed a patent and is expanding testing to other regions

Although the two projects used different methods, one a Texas field test and the other laboratory testing in India, they reached similar conclusions. Adding a small amount of recycled plastic to petroleum bitumen appears to improve asphalt quality while helping divert waste from landfills. Hossain and his colleagues have filed a patent for the technique and are conducting trials in other regions, suggesting the Dallas pilot could help address two waste problems.