New Zealand Cycleways Recycled Cycleways

28 September 2018 Chloe Brigden

Last week, the city of Zwolle in the Netherlands unveiled the world's first bicycle lane using 70% recycled plastic. The study was conducted by PlasticRoads and consisted of a 30 metre, two-lane bicycle path made from recycled plastic bottles, cps packaging and furniture. 

According to PlasticRoad, due to the prefab production, plus the lightweight and modular construction of the material, construction and maintenance can be achieved faster, easier and cheaper - compared to traditional road surfacing materials. 

The cycle lane is being received well by the community of Zwolle. This comes as no surprise; the city is already known as 'one of the greenest cities in Europe' and is celebrated for its well-tuned cycling culture. 

Meanwhile, with New Zealand's huge transportation overhaul (plus the $28 billion budget to fund it) questions are being raised to whether we will see such innovation trickle down to Aotearoa. 

The answer? They already are...three years ago to be exact. 

Our pavement research and behavioural science teams investigated used tyre-rubber derived asphalt for a cost-effective, adaptive and all-around superior cycling material. 

This work is being done in partnership with the Ministry for the Environment (MfE) as part of the annual Waste Minimisation Fund - looking at various ways to minimise different waste streams and divert end-of-life materials away from landfills. 

The MfE project was also co-funded by the NZ Transport Agency with technical support from Fulton Hogan. Councils are also focusing on speeding up the adopting circular economy in New Zealand -  instead of the traditional take, make, waste outlook - councils are seeking to encourage the optimisation of a materials end-life. Our joint work and tyre-rubbing asphalt are a salient response, particularly in light of New Zealand's recent waste management crisis resulting from China's 'no more' message to overseas imported waste. 

Can we fulfil sparing our landfill? 

Enter Jeremy Wu, Research Manager of Transport for WSP Opus. 

Almost 5 millions tyres go to waste each year in New Zealand. Jeremy and his team have been trialing a rubberised asphalt surfacing (recycled tyres) alternative for bicycle lanes - spring landfill space whilst offering a quality ride for cyclists. 

The pilot has been running since 2017 in Upper Hutt near Totara Park. Upper Hutt City Council provided the 2 Km trial site in support of the feasibility of the study. The rubberised section is about 1 km long and is placed right next to a 1 km section of normal asphalt. The amount of rubber modifier used in the cycleway equates to approximately 25 truck tyres. 

Using one of our instrumented bicycles, we analysed the ride quality over traditional cycleway surfacing. The surface appeared to be easier to ride on because of the slightly reduced friction. Using a suite of lab-test methods, our material specialists have also measured the properties of the rubberised material (compared against its traditional benchmark) and concluded that it is superior in a range of mechanical properties and more durable over the benchmark. 

The rubber also modifies the bitumen and this, the asphalt mix to be more elastic and less susceptible to extreme temperatures. 

Our behavioural science researchers have conducted two intercept surveys over the past 12 months. Feedback on the concept has been extremely positive, the community have welcomed and praised their new rubberised asphalt cycleway. “On appearance, it looks no different to ordinary asphalt cycleways… There hasn’t been a huge barrier for the acceptance of a new product especially when the public recognises the need to find solutions to waste tyre disposal.” - Jeremy Wu

How do we see this idea developing?

The logical step would be to expand this material into roads where the volume of use is higher and thus making more of an impact to waste minimisation but also to make it economically viable through the economy of scale.

Jeremy said: “This can be more than just recycled tyres. In fact, it already is. The material used in Upper Hutt was a mixture (a composite) of tyre rubber with recycled low and high-density polyethene (LDPE and HDPE). There are other examples from contractors in NZ on how the industry is proactive in pursuing the use of recycled materials such as recycled crushed concrete, waste glass, waste plastic oil bottles, and waste toners in our roads. The aspiration of the project would be to see recycled surfacing becoming more mainstream across the country.”