India’s Plastic Roads

India struggles with mountains of plastic waste because, like many other developing countries, it lacks waste management infrastructure to deal with post-consumer plastic. Garbage collection is neither reliable nor widespread. If waste is collected, it is more likely to go to an open, leaky dump than a secure, engineered landfill that holds waste in. Armies of waste pickers scour dumpsites for anything of value, and in this is way some plastic is recycled, but much of the plastic that’s thrown out has no value. Waste pickers collect and recycle high quality plastic like PET (what water and soda bottles are made of) but leave lower value plastics like bags, single-use pouches and foam containers. Waste pickers can’t make enough money on these, so low-value plastics pile up in the environment.

India also struggles with bad roads and many fatal traffic accidents. The country has the second largest network of roads in the world, but many are in terrible condition. Monsoon rains and extreme heat degrade asphalt roads quickly. Road maintenance is poor. The result is roads with potholes that are big enough to swallow trucks whole. There are around 150,000 traffic deaths per year in India, and about a tenth of these are caused by potholes.

Rajagopalan Vasudevan, chemistry professor at Thiagarajar College of Engineering, is tackling both of these problems at once. Experimenting in his laboratory with a wok, a thermometer, shredded plastic waste and asphalt, he found that plastic, which is derived from petroleum, and asphalt, which is a form of petroleum, bind well with each other when heated. Asphalt mixed with plastic binds much better to gravel than asphalt alone, resulting in better roads. By replacing 10 percent of the asphalt used to build roads with shredded plastic scrap, roads last three times as long as traditional asphalt roads and are less likely to crack or form potholes. They are also cheaper to build because plastic waste is much less expensive than asphalt. A variety of plastics can be used for building roads, including low-value plastics that would not otherwise be recycled.

Professor Vasudevan, who’s also known as India’s Plastic Man, built the first plastic road in 2002 at his university. Now there are 100,000 km of roads built with plastic in India, with many more kilometers of road coming soon. India has committed 11 billion dollars over the next five years to improve and expand roads, and since a 2015 government mandate, all new highways are required to be built with plastic waste.

Each kilometer of new road consumes 1 ton of post-consumer plastic. Plastic in the roads means less plastic along roadways, better roads and fewer traffic fatalities. Plastic roads also mean more income for waste pickers. There is a demand now for plastic that would otherwise end up in the environment and waste pickers can earn a living by collecting it. The government sells subsidized plastic shredders to groups of waste pickers who collect, sort and shred plastic scrap and then sell the shredded plastic to road builders. Other countries are watching India’s low-tech, plastic road experiment with great interest.

Plastic has been added to roads since the 1970’s in North America, Europe and Saudi Arabia, but these are built with virgin plastic or crumb rubber (shredded tires) and are more expensive than regular asphalt roads. There are new designs being tested for snap-together road panels built completely with plastic waste, but that is a topic for a later post.

Innovations like India’s plastic roads will help solve our ocean plastic problem. In the meantime we can all help. Grab a clean, used plastic bag from the BlueTube at your beach, pick up plastic, keep it off the beach and out of the ocean.