The old road outside South Sioux City used to be just gravel and cracked blacktop.
Then a paving crew showed up with a mix nobody in Nebraska had ever poured before.
Buried inside the steaming asphalt were the shredded remains of two million plastic bags.
Nobody was pretending it was a finished product.
It was a test, laid on a real road that real trucks actually use.
So what does four thousand feet of melted grocery bags do to a road once winter arrives?
Melted plastic film coats the rock instead of filling gaps
The trick is not dumping plastic into asphalt like filler. Engineers used shredded low density polyethylene film, the kind used in grocery and trash bags, melted into the hot mix so that it coats the stone rather than sitting loose in the voids between it, alongside the sticky bitumen binder that holds a road together.
Why that coating might help is still the part under study. The working explanation is that the plastic film changes how the binder grips the aggregate underneath, so the plastic becomes part of the glue rather than a weak inclusion inside it.
That explanation is being tested, not treated as settled.
The mixture also includes 25 percent reclaimed pavement, meaning old torn up roadway reused instead of fresh rock, a material Nebraska’s transportation department already uses widely. The road leans on two waste streams at once, which is part of why the city wanted it.
A 4,000 foot stretch near a city park became the real test site
South Sioux City built the stretch of Foundry Road near Siouxland Freedom Park using an asphalt blend made from two million recycled plastic bags, making it the first roadway in Nebraska built with plastic containing asphalt. Local news crews filmed the paving, and the city held a ribbon cutting beside the park to mark it.
The project lead, Jamilla Teixeira, an assistant professor of civil and environmental engineering at the University of Nebraska-Lincoln, called it exactly what it was rather than a finished solution.
“This is a pilot project, but it is an excellent opportunity to partner with a Nebraska community and test how the mixture will perform under the extreme weather conditions we have here,” Teixeira said.
Money for the work came from a $500,000 grant from the Nebraska Environmental Trust after South Sioux City applied for funding.
Thousands of simulated truck passes came before real traffic
Before any truck touched Foundry Road, paved in June 2025, the blend went through torture tests on campus. One method, the Hamburg Wheel Tracking Test, rolls a loaded steel wheel back and forth across a submerged slab for thousands of passes to compress years of traffic and moisture damage into days.
The state funded feasibility report describes the field mix as a Nebraska Superpave recycled mixture with 25 percent reclaimed pavement and 1 percent post consumer low density polyethylene, produced at a commercial asphalt plant rather than only in a lab. Across the testing, the plastic modified mixtures showed improved rutting resistance and moisture resistance while holding their short term cracking resistance.
Polyethylene outperformed polypropylene on moisture damage. That matters because plant production, not lab mixing, is what a city would actually buy.
Monitoring after one winter still leaves the fix a pilot
None of this means the method is ready to spread across Nebraska highways. The university has stressed that Foundry Road is a pilot project, not proof that recycled plastic asphalt can replace conventional mixtures statewide, and that caution still holds.
Even so, the installation gives researchers something rare: a real road, rather than a lab slab, to inspect after every freeze and thaw cycle. The feasibility project closed at the end of January 2026, and follow up work now targets long term field performance and whether pavement containing plastic can still be milled up and reused as reclaimed asphalt later. A road either holds through a Nebraska winter or it does not, and no lab wheel fully substitutes for actual frost heave and snowplows.
Years of seasonal checks will decide if more roads follow
As monitoring continues, researchers are watching the pavement under traffic and Nebraska’s weather swings to see how it responds to moisture and seasonal temperature change. The staged approach, lab first and field second, mirrors other engineering pilots built around defined conditions before any wider rollout.
Crews elsewhere have tried similar fixes, including a Texas highway repaving that worked shredded plastic into asphalt near Dallas, after test sections in parking lots. That team’s lead researcher has pointed to a 2024 lab estimate that recycled plastic asphalt sheds roughly a thousand times fewer microplastics than worn tires, while noting the shedding question over years is still open.
For now, the honest answer sits right under the wheels of anyone driving past Siouxland Freedom Park. The road is holding so far, and that is why the researchers keep going back to check.
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