Readers of this newsletter know that plastic pollution is an urgent crisis. But, as if the 299 million tons of plastics the world produces a year were not enough, the situation is actually getting worse. China had imported 40 percent of America’s plastic waste, as well as other recyclables, for the last 30 years, but abruptly banned the imports in 2017.1
This has had dire consequences and the market for recyclables has all but collapsed, leaving cities that depended on exporting to China with no buyers.
The same cities that used to earn a profit from selling their recyclable plastics and waste now must pay to have it hauled away and worse: Some are now burning their plastic waste. Incinerating plastic is, of course, a major source of air pollution, including carbon and greenhouses gasses, and no solution to plastic pollution.2 Los Angeles County has incinerated about 20,000 tons of plastic in since 2018!3
Also, those ubiquitous single-use plastic bags that so many stores refuse to discontinue are too thin to recycle along with harder plastics because they get caught in the processing machinery.4 That means they need to go to a special drop-off location for disposal — but how many people make that extra effort? The presence of single-use plastic bags all over the environment is our answer. Clearly, we need some new recycling ideas and, luckily, there are some.
Could We Recycle Plastics Into Roads?
Modifying asphalt with added plastic asphalt polymers is not a new idea. Such roads, made from virgin polymers and sometimes ground tires, have been used for decades to make high-traffic truck roads, reduce noise reduction and prevent roads from cracking from weather extremes, especially in Western countries.5
But plastic roads made with discarded, low-grade polymer are a relatively new idea that is gaining traction. It’s an idea that not only avoids creating new, virgin plastic, but reduces existing plastic waste.
In fact, every kilometer of road made with low-grade, discarded plastic uses 1 million plastic bags, saves 1 ton of asphalt and costs 8 percent less than conventional roads.6 Asphalt production is polluting, emitting 96 million tons of CO2 in the U.S. alone.7 Here is how the plastic road movement got started in India, according to the Guardian.8
Dr R Vasudevan, a chemistry professor and dean at the Thiagarajar College of Engineering in Madurai, came up with the idea through trial and error, sprinkling shredded plastic waste over hot gravel and coating the stones in a thin film of plastic. He then added the plastic-coated stones to molten tar, or asphalt. Plastic and tar bond well together because both are petroleum products.
A modified version of the road which adds road scrap to plastic-coated gravel was tested out in March this year on a highway connecting Chennai with Villupuram. It was the first time plastic road technology was used for a national highway. It is expected to reduce construction costs by 50%.
An Early Plastic Road in India Passes the Stress Test
Jambulingam Street was one of India’s first plastic roads. Built 17 years ago, it proved to be surprisingly durable and has won favorable reviews from all segments of society. According to The Guardian:9
The tar road in the bustling Nungambakkam area has weathered a major flood, several monsoons, recurring heat waves and a steady stream of cars, trucks and auto rickshaws without showing the usual signs of wear and tear.
Built in 2002, it has not developed the mosaic of cracks, potholes or craters that typically make their appearance after it rains. Holding the road together is an unremarkable material: a cheap, polymer glue made from shredded waste plastic.
Soon, the idea of plastic roads spread to neighboring countries like Bhutan, and the roads were given good reviews by the authorities:
"The plastic tar roads have not developed any potholes, rutting, raveling or edge flaw, even though these roads are more than four years of age," observed an early performance report by India’s Central Pollution Control Board. Today, there are more than 21,000 miles of plastic road in India, and roughly half are in the southern state of Tamil Nadu. Most are rural roads, but a small number have also been built in cities such as Chennai and Mumbai.