Plastic Roads: How One Man’s Trash Could Be The Future Of Roadway Construction

A Sustainable Solution To Plastic Waste

Worldwide plastic production has accelerated rapidly over the past six decades. While the introduction of plastic is a fairly recent, plastic has found itself into the production of almost everything throughout the world economy.

Everything from forks, computers, and cars have some components that are made out of plastic. As a result, humans have produced 18.2 trillion pounds of plastics since the early 1950s, and about 80% of that plastic now sits in landfills or litters our environment.

The mass adoption of plastic was seen throughout the world because plastic is a cheap and relatively easy material to use for a variety of industrial applications.

While the production of this plastic can be seen as a good thing for the advancement of industry and national economies, the negative aspects of plastic are seen when we consider that most plastic material that is thrown out could be recycled.

Here in the U.S., our environment is being filled with flimsy, single-use items like shopping bags, plastic packaging, and other things. This plastic garbage is not only overwhelming our landfills at an unprecedented rate, but they are also clogging city drains and cluttering public areas. 

While some environmental groups are looking for ways to reduce the production and use of plastics in consumer goods, other scientists are finding new and innovative ways to use plastic throughout our economy.

One way that scientists and engineers are recycling plastic items is in the application of plastic in our city streets.

Recycled Plastic To Strengthen Public Roads

Utilizing recycled plastic in road construction is not a new concept, but this approach to sustainable roadway design is starting to see newfound attention. Not only is this approach to roadway construction and repairs improve the strength of the roadways surface and pavement, but it also reduces the amount of plastic that goes to landfills.

Pavement that is constructed using waste plastic has many benefits outside of reduced cracking, including:

  • Improved drainage of drier roads with better grip even in rain and snow.
  • Increased resistance towards rainwater and stagnant water.
  • Reduced development of potholes and cracks in the pavement.
  • Enhanced binding of the asphalt mixture.
  • Dampened roadway noise pollution from traffic patterns.
  • 1 km of roadway saves about 1 ton of plastic and 1 ton of bitumen.
  • Reduced roadway construction costs and maintenance over time.
  • Introduce employment opportunities to search and sort plastic waste materials.

Roadways that use this advanced construction technique tend to use plastic carry bags, disposable cups, and personal water bottles that currently litter our cities across the U.S.

When mixed with traditional asphalt ingredients, the plastic material melts to form an oily coat over the aggregate of stone and sand in the pavement.

This sticky substance improves the bond of sand and other asphalt materials and adds a protective layer that also improves the performance of the road’s pavement. As a result, the polymer-mixture helps make roadways stronger, it also increases the lifespan of roadways before regular maintenance.

This approach to roadway construction continues in the newest iteration of plastic roadways and is seeing great success in cold climates like Illinois and Washington state. In these regions where seasonal weather shifts can cause cracking to pavement that creates potholes, the modified asphalt mixture proves to improve resistance to cracking and pavement potholes.

How Can Plastic Roadways Benefit Motorists & Our Cities?

Mixing flexible materials into traditional asphalt aggregate was first implemented in Europe during the 1970s. The original approach used virgin polymers and even ground up tires to make a mixture that was highly versatile and sustainable.

Not only does a polymer-modified asphalt reduce the chances of potholes, but they also add to noise reduction in high-traffic truck roads. This means that polymer roadways can reduce the financial stress that cities face by minimizing required maintenance, and they can also make our cities more quiet by muting traffic noise from traveling vehicles.

Polymer-modified roadways could also benefit roads that see frequent heavy truck traffic or slow-moving truck traffic. This is because polymer-modified asphalts tend to be more viscous (thicker) than traditional asphalt, and this can cause the roadway surface to be stickier.

The higher viscosity and improved adhesion offered by the plastic materials help resist pavement from rotting when heavy loads are introduced to the roadway.

The polymer materials mixed into the asphalt materials can make roadways more elastic that reduces fatigue of pavement as repeated cycles of heavy trucks move the lifetime of the pavement.

Lifetime Costs Could Offset Higher Initial Construction Costs

While many benefits come with polymer-modified roadways, one of the most prominent issues that prohibit the mass adoption of this construction process is initial costs.

The most popular polymer used in the U.S. is styrene-butadiene-styrene and using this product can increase initial construction costs by 30-50% compared to traditional asphalt roads.

Most roadways constructed in the U.S. that are made with a polymer mixture are made of asphalt with pre-mixed polymer material aggregate. This mixture tends to be made from low-grade polymer materials that can save millions of plastic bags for each mile of roadway construction.

The overall project costs involving polymer-modified roadways tend to be quite small because while polymers may add expenses of the binder, this mixture only accounts for a small portion of the overall aggregate.

However, as lawmakers and engineers work together to understand the viability of plastic roads, they must also consider the reduced roadway costs they will have to invest in the future.

Since polymer-modified roadways improve the resistance to cracking and rotting under high traffic areas, city officials will be able to reduce construction costs since fewer potholes will develop throughout the year. Not only will this improved roadway performance help city officials balance their budget, but the enhanced surface could also improve traffic safety for all drivers.

Redefining The Future Of Road Construction With Recycled Waste

As the innovative construction methods utilize new materials like recycled plastic, engineers will need to work with policymakers to find ways to reduce the burden of waste on our environment.

While cities become more populated and our impact on our environment increases, utilizing recycled plastic waste in our roadway construction projects could be one way to reduce pollution and financial stress on annual budgets while also improving public safety for all motorists. 

Let’s keep an eye out for how cities of the future integrate this exciting approach to recycling and roadway construction into their city development process!