Could Plastic Roads Be A Sustainable Alternative?

While we generally associate plastics with the untenable generation of material waste, this need not necessarily be the case. Dutch consortium VolkerWessels hopes to demonstrate that building plastic roads may in fact be a more environmentally friendly option for our transportation infrastructure.

Plastic roads and bike paths: this design concept by Dutch consortium VolkerWessels promises to be a sustainable alternative to asphalt paving.Plastic roads and bike paths: this design concept by Dutch consortium VolkerWessels promises to be a sustainable alternative to asphalt paving.

The design of the plastic road is quite simple: modular components would be prefabricated and then snapped together like tiles to form an extended road. Unlike traditional asphalt, the ‘tiles’ would be hollow allowing the easy subterranean incorporation of cables, pipes, or rainwater flow channels. The concept offers a number advantages over a traditional road surface. Primary among these is the ease of construction and installation. The plastic roads, which are of course considerably more lightweight than any alternative, can be completely prefabricated before transportation to the road site. This includes not just the road surface, but also guardrails and road markings. This will save considerable time for manufacturers which translates directly to cost savings. Additionally, the use of plastic materials, which can be synthetically manipulated by chemists, allows for the incorporation of new functionality to the road surface. For example, solar heated roads, light poles and traffic loop sensors. Recently, the same Dutch industrial partners have also introduced Flow With The Glow, a smart material that is based on photoluminescence and can make road markings and guide rails visible in the dark without electricity. Plastic roads can also be easily molded into structures that reduce noise pollution.

So how could this widespread deployment of plastics actually benefit our environment? Well, there are several key components of the project that ensure its sustainability. The foremost is the plan to use recycled plastics exclusively. The project designers point to the floating garbage islands in our oceans as a major source of materials. Indeed, an estimated eight billion kilograms (17.6 billion pounds) of plastic is estimated to persist in our oceans currently. And 55% of our plastic waste is still incinerated rather than recycled. Harvesting these materials to produce roadways would actually clean our environment rather than pollute it. Using such lightweight materials will also limit the need for the heavy construction vehicles typically required for asphalt road installation and these tend to be major gas guzzlers. Finally, the plastic roads are estimated to have a significantly longer lifetime – at least three times that of standard pavement. This is because not only are the materials themselves more durable, but they are also less susceptible to buckling and cracking from adverse weather conditions, with a safe temperature range of -40 °C to 80 °C (-40 °F to 176 °F), or the growth of weeds. At the end of their lifetime, the plastic roads can also potentially be recycled again.

Marine debris: today's ocean trash, shown here on the Hawaiian coast, may be tomorrow's roadways.Marine debris: today's ocean trash, shown here on the Hawaiian coast, may be tomorrow's roadways.

There are of course challenges and plastic roads remain only a concept for now. Studies need to be undertaken to determine their effectiveness in wet and slippery conditions and fire retardant coatings will likely have to be developed. The companies involved are thus starting simple, with the production of plastic bike pathways – a clever idea that will allow mastery of the fabrication and assembly process without major financial investment or government involvement. Luckily, the city of Rotterdam is always enthusiastic about bold new advances and has approved the idea of plastic roadways on a trial basis. Says city council engineer Jaap Peters, “We’re very positive towards the developments around PlasticRoad. Rotterdam is a city that is open to experiments and innovative adaptations in practice.”

If all goes well, you may soon see plastic roads or bike paths coming to a city near you!