PlasticRoad: The Dutch Plan to Build Roads From Recycled Plastic

Did the Netherlands really start paving its roads with recycled plastic? Not quite. In July 2015 the Dutch construction group VolkerWessels unveiled PlasticRoad, a concept for prefabricated, hollow road sections made from recycled plastic instead of asphalt, and said Rotterdam was interested in a trial. Headlines quickly turned that into "the first country to pave its roads with plastic". What actually happened was slower and smaller: the first PlasticRoad was a 30-metre bicycle path, opened in Zwolle in September 2018, followed by a second in Giethoorn.

Here is how the idea works, what the pilots showed, and what questions remain about building roads from plastic waste.

The 2015 proposal

VolkerWessels and its road-building subsidiary KWS presented PlasticRoad as a radical rethink of how roads are made. Instead of laying hot asphalt on site, the plan was to manufacture lightweight road modules in a factory from recycled plastic, then truck them to the site and click them into place.

The company highlighted several potential benefits:

• Faster construction: modules could be installed in days or weeks rather than months, reducing traffic disruption and on-site work.
• Hollow sections: the empty space inside each module could carry cables and pipes, or store rainwater during heavy storms.
• Durability: the company claimed the material could cope with temperatures from roughly minus 40 to plus 80 degrees Celsius and would need less maintenance than asphalt.
• Recycling: the modules would give a use to plastic waste and could themselves be recycled at the end of their life.

Rolf Mars of VolkerWessels told the Guardian that Rotterdam was keen on a pilot: Rotterdam is a very innovative city and has embraced the idea. He also floated future add-ons such as heated or extra-quiet surfaces. Early reports suggested a test road could be ready within about three years.

From road plan to bike-path pilots

Turning the concept into something you could ride on took longer, and the first application was bikes, not cars. KWS teamed up with plastic-pipe maker Wavin and energy company Total, and designers Anne Koudstaal and Simon Jorritsma refined the modules.

On 11 September 2018, a 30-metre recycled-plastic cycle path opened in Zwolle, in the province of Overijssel. Guinness World Records lists it as the first bicycle path made from recycled plastic. The makers said it contained plastic equivalent to about 218,000 plastic cups. A second 30-metre path followed in the village of Giethoorn.

Both pilots were fitted with sensors that tracked how they were used and how they behaved, around the clock. By late May 2020 the two paths had recorded their millionth bicycle crossing.

What the tests showed

In May 2020, after about 18 months of testing, the partners announced that the design was ready for market. According to VolkerWessels:

• The paths coped with heavy vehicles such as rubbish lorries and maintenance trucks, and the production version would be about 2.5 times stronger than the test sections.
• Rainwater storage worked as intended. In Zwolle, the highest water level reached 48% of the available capacity, and the water soaked into the ground within about two days.
• Each pilot used roughly a tonne of recycled plastic, and the company estimated CO2 emissions 50 to 70% lower than for comparable asphalt or concrete bike paths, a figure it said was checked in an independent circularity audit.

The next targets were bike paths, car parks, pavements and schoolyards, first in the Netherlands and neighbouring countries. Motorways carrying heavy car traffic, the original 2015 vision, were described as a longer-term goal.

Why replace asphalt at all?

Asphalt is a mixture of stone aggregate bound with bitumen, a heavy product of crude oil refining. Producing and laying it requires heating large volumes of material, which uses energy and releases greenhouse gases and fumes. Dark asphalt also absorbs sunlight and contributes to the urban heat island effect, where city centres stay hotter than surrounding countryside.

At the same time, the world produces far more plastic waste than it recycles into high-value products. A road that both lowers construction emissions and creates demand for recycled plastic is an attractive idea for governments trying to meet climate and circular-economy targets. Modular sections also suit the Netherlands well: the country is low-lying and wet, so a road that can buffer stormwater has obvious appeal.

Other ways plastic ends up in roads

PlasticRoad is one of several approaches, and they work quite differently:

• India: chemist Rajagopalan Vasudevan of Thiagarajar College of Engineering developed a method in the early 2000s for coating hot aggregate with shredded waste plastic before mixing it with bitumen. Thousands of kilometres of Indian roads, including stretches of national highway, have since been built this way.
• United Kingdom: the company MacRebur makes plastic pellets that partly replace bitumen in asphalt. In 2019 the UK Department for Transport announced a £1.6 million trial, and Cumbria was among the first councils to use it.
• Netherlands: PlasticRoad stands apart because it replaces the whole road structure with plastic modules, rather than adding plastic to asphalt.

Open questions and criticism

Plastic roads are not a settled success. Engineers and environmental scientists raise several concerns:

• Microplastics: as any road surface wears, small particles break off. With plastic, those fragments may end up in soil and waterways, and they can absorb other pollutants. Long-term data are still limited.
• Long-term durability: mixing different types of plastic can create weak points that fail early, and experts have called for more research on how modules age under years of weather and traffic.
• Repairs: if pipes and cables run through a modular road, fixing a section can mean disrupting those services.
• Scale: a pilot path using about a tonne of plastic barely dents national plastic waste. Reducing plastic use in the first place matters far more than finding new places to put it.

The fairest summary is that PlasticRoad proved the concept works for light-traffic surfaces such as cycle paths, while its promise for busy roads is still unproven.

The bottom line

The Netherlands did not become the first country to pave its roads with plastic bottles. A Dutch consortium did design a genuinely new kind of road, built from recycled plastic modules, and in 2018 opened the world's first recycled-plastic cycle path in Zwolle. Its pilots handled heavy vehicles and stormwater well, and the makers report lower emissions than asphalt. Whether plastic modules can one day carry cars and lorries at scale, without creating new pollution problems, is the question the next decade of testing will need to answer.

Sources: Guinness World Records: First recycled-plastic bicycle path; VolkerWessels: PlasticRoad ready for market (May 2020); DutchNews.nl: Recycled plastic roads ready for rollout (May 2020); Wikipedia: Plastic road; VolkerWessels.

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