Scientists are extremely concerned that the world has been mass-producing plastics since the mid-1950s to the point that we are now becoming Planet Plastic. From Mount Everest to the deepest oceans, vast amounts of plastic waste contaminate the entire planet. In the last 65 years, we’ve produced nine billion tonnes of the stuff. And plastic production is set to double in the next two decades. Only 9 percent of that is recycled, so 91 percent ends up in landfills. And none of these commonly used plastics are biodegradable. Even more concerning, fragmented microplastics are showing up in human bodies worldwide, even in newborns, and nursing mothers’ milk. We inhale or ingest tiny, invisible plastic fibers floating in the air around us, fibers shed by our own clothes, carpets, and upholstery, etc. We know that microplastics damage human cells in the laboratory, and air pollution particles already enter the body and cause millions of early deaths a year.
So some good news: roads internationally are now starting to be built from waste plastics –trash from the ocean, plastic bottles, grocery bags, yogurt containers, and even, surprisingly, from used disposable diapers, which Wales in the U.K. first began. This latter is welcome news indeed, as the US throws out 18 billion used diapers a year. But don’t worry, say the experts, diaper roads smell like roads, not baby poop.
Each mile of road built with plastic removes the equivalent weight of more than one million plastic bottles or 2.8 million single-use plastic bags from the environment.
“We created a repaved stretch of highway in Oroville, California, that looks like an ordinary road, but is the first highway in the country to be paved with recycled plastic–then the equivalent of roughly 150,000 plastic bottles per mile of the three-lane road. Now it is 1,600,000 per lane mile. Plus two more road sections in L.A. that are performing very well,” Sean Weaver, president of TechniSoil, Redding, CA., told SEEDS. “And this year and next, we have two more projects in Minnesota and Michigan. We also built one for the Democratic Republic of Congo six months ago, and will be doing a 75-mile pilot for them next. This new type of road is much more resistant to potholes and cracking and lasts two to three times longer than standard asphalt. They are also much more resistant to heat, cold and flooding. And because it lasts much longer than asphalt, it is much cheaper over its life cycle.”
Roads built from plastic also do not absorb water, have better flexibility which results in less rutting and less need for repair. Surfaces remain smooth, are lower maintenance, and absorb sound better. Roads built with plastic can withstand extreme temperatures (from minus 40F to 176F) much better than traditional asphalt roads.
TechniSoil uses PET plastic to design roads, Weaver says, which is the clear and lightweight plastic that is widely used for packaging foods and beverages, especially convenience-sized soft drinks, juices and water. Virtually all single-serving and 2-liter bottles of carbonated soft drinks and water sold in the U.S. are made from PET. “We also use the distressed or unwanted PET such as delivery food containers, food bags from the grocery store, straws, carpet, packaging waste, and industrial waste. Basically, it’s the 90 percent or more of PET that goes to the landfill,” he explains.“We recycle the plastic waste chemically back into its original monomers. Then use those monomers to build a new polymer called Neo Binder. It’s like super glue, just with properties that are ideal to bond recycled asphalt together.”
Encouragingly, road contractors already have all the equipment needed to build plastic roads, says Weaver. And even more positive news, there is no concern about plastic roads causing microplastic for us to inhale. “Our binder is chemically converted from plastic to an elastomer that is chemically bonded to the aggregate,” he says. “Even when it is recycled twice, or 100 years from now, it can be ground up and used for base rock without any shedding of microplastics into the environment.”
But in this new technology, the U.S. was late to the game. The first country to recycle plastics for roads was India, which started doing it 18 years ago, when the city of Chennai, formerly known as Madras, and India’s fifth largest city, commissioned 1,000 kilometers of plastic roads. The plastic road was invented by Prof. Rajagopalan Vasudevan, at Thiagarajar College of Engineering, an Indian scientist, who specializes in waste management concepts. For his innovative method of using plastic waste for roads, he was awarded the Padma Shri, one of India’s highest civilian awards.
Since then, India’s fishermen have been turning ocean plastic into roads. They started doing this when they realized that their shrimp and fishing nets were bringing up more plastic than fish. Fishing crews were spending hours separating the plastic garbage from their catch as the nets were heavily weighted down with all the plastic tangled in them. Now, some 5,000 fishermen from the state of Kerala, for example, have been hauling back to land all the plastic they find while they’re out at sea. With help from several government agencies, according to National Geographic Magazine, they’ve set up the first-ever recycling center in the region, to clean, sort, and process all the tons of sea-tossed plastic bags, bottles, straws, flip-flops, and drowned Barbie dolls they fish out.
Another concern about ocean plastic is that many types of fish mistake plastic for prey; studies show that they can die of either poisoning or malnutrition as a result. Other marine life gets caught in and strangled by abandoned nylon fishing nets. And large patches of plastic on the sea bed block some species from accessing their breeding grounds.
Initially, however, the region had no municipal waste collection, or recycling program.
But in 2018, the female state minister of fisheries came up with a solution after roping in five other government agencies, including the department for women’s empowerment. That agency is tasked with improving employment opportunities for women, in an area where many fields, like fishing, had long been dominated by men. So the agency hired an all-female crew to work there.
For the past four years, a group of women have been working full-time to painstakingly wash and sort plastic that the fishermen collect. Most of it is too damaged and eroded to recycle in traditional ways. Instead, they sell it to local construction crews who use it to strengthen asphalt for paving roads. The proceeds—along with government grant money—cover the women’s salaries.
Since 2009, the northern European environmental group KIMO has been recruiting fishermen in the U.K., the Netherlands, Sweden, and the Danish Faroe Islands for a similar program called Fishing for Litter. Globally, there are now 5.25 trillion pieces of plastic waste estimated to be in our oceans. I was shocked, for example, when visiting Bali three years ago, once known for its stunningly beautiful beaches, to find them covered in broken-down plastics, which the tides brought in every day. “The world is facing a tsunami of plastic waste, and we need to deal with that,” says Dr. Erik van Sebille of Utrecht University in the Netherlands, an oceanographer who tracks plastics in our seas.
Climate change is threatening to all infrastructure, but plastic roads mitigate flooding, are easier to maintain, and can be recycled up to seven times. They are also four times lighter, 70% faster to build, last three times longer, and produce up to 72% fewer carbon emissions than conventional roads.
In the last couple of years, countries as far afield as Australia, Dubai, South Africa, Germany and Taiwan are now constructing roads from waste plastic. Ah, if only we could persuade Penn-DOT to do the same. According to a recent study, Pennsylvania’s road infrastructure ranks fifth worse in the nation, as anyone driving over our constant terrain of potholes here knows. The study found that 30 percent of the Keystone state roads are in poor condition. And yet PA pays the 4th highest gas prices in the country, next only to California, Oregon and Washington, because of taxes on our gas, which is meant to go toward road repair! Where does that money go?
It turns out that Penn-DOT is currently testing an asphalt modified with recycled plastics in a pilot project through its Strategic Recycling Program, their spokesperson Alexis Campbell told SEEDS. The project is only two quarter-mile road sections in which recycled plastic asphalt modifier was used as a 2% additive to the binder in the road’s wearing course. “While this does not seem like a lot, it equates to recycling approximately 150,000 single-use plastic bags,” she says. The project in Delaware County will be monitored for sustainability for five years.
In the meantime, get used to our roads craters and ditches. “With Pennsylvania’s aggressive freeze-thaw cycle, our roadways will always experience potholes. Pavements in other states that do not experience similar freeze thaw cycles as Pennsylvania are not as susceptible to them,” says Campbell. “States to our north and in Canada may be colder but they do not experience the same number of freeze-thaw cycles. Also contributing to pavement deterioration is the large volume of heavy trucks that utilize Pennsylvania’s roadways daily throughout the year. Given PA’s geographical location, our Interstates serve as major freight corridors to the northeast.”
She adds: “PennDOT is reliant on gas taxes for 78 percent of its highway and bridge funding. We are far more dependent on this revenue source than any of our surrounding states. Gas tax revenues have been declining heavily over the past several years, due to changing travel patterns and more fuel efficiency. Our outsized reliance on gas taxes makes Pennsylvania’s transportation system incredibly vulnerable to market changes like we’re seeing now.”
Jan Goodwin is an award-winning journalist and author.
Photo credit: CalTrans.