We have a waste plastic problem but EiD was not expecting to see it used for resurfacing roads. Tom Bawden writes on The i newsletter about latest developments.
Why plastic roads could be the future
Carrier bags, bottles and nappies will be used to resurface roads and fill potholes across Cumbria – leading a government push into plastic roads that could eventually see household waste added to road surfaces all over the country.
The roads will use a plastic mix made out of everyday household waste which is added to the tarry bitumen that glues together our rocky asphalt road surfaces.
Advocates such as MacRebur, the Lockerbie-based company that developed the mix, say it provides a green solution to the road crisis by using waste plastic that would have been burned or sent to landfill to mend surfaces.
The new waste-plastic enhanced bitumen is also cheaper, stronger, longer lasting and more flexible than standard bitumen, they say.
Cumbria has been trialling the new plastic road mix for two years on a handful of short stretches of roads, junctions and roundabouts to test its performance.
Happy with the results so far, the county is about to significantly step up its plastic roads programme. This will see the unofficial plastic road capital of the UK using the mix in a much wider range of road projects over longer stretches.
“Plastic roads appear to have huge potential. We hope to demonstrate that waste plastic could be widely adopted in our roads, not just here in Cumbria but right around the UK and potentially even globally,” said Stephen Hall, assistant director of highways and transport at Cumbria County Council.
“If plastic roads are widely adopted there is the potential to offset vast amounts of plastic that around the world is just piling up,” he said.
Like plastic, bitumen is derived from oil – so the two substances are extremely closely chemically related.
This means they can be melted together seamlessly into a tarry mass so road users would never know they’re driving on old breadbags, magazine wrappings and water bottles.
But while they might look the same as any other stretch of road, every hundred square metres of road laid using MacRebur’s mix contains the equivalent of 435,592 single-use carrier bags worth of plastic. Or 71,432 throwaway bottles, or 32,399 nappies.
This plastic makes up about six per cent of the bitumen used on the road surface – although the proportion could be increased several times over, taking even more waste out of the system, advocates say.
Even at six per cent, you could make a huge dent in the country’s waste crisis, MacRebur boss Toby McCartney argues. Resurfacing every road in Cumbria would require 800 tonnes of plastic – more than the 500 tonnes of waste plastic the county produces each year, he says.
The government threw its weight behind plastic roads last week and selected Cumbria to lead the charge.
It has given the county £1.6 million to gather further evidence about the effectiveness of plastic roads and to produce a guide for other local authorities wanting to introduce them.
“Potholes are the number one enemy for road users…This trial will see how new technologies work in the real world to ensure our roads are built for the 21st century,” said Transport Secretary Chris Grayling.
The RAC was called out to help with 1,714 breakdowns caused by potholes and poor road surfaces in the last three months of 2018 – while more than 674,000 potholes have been reported in the UK in the past 12 months.
The government funding will enable Cumbria council to work with MacRebur and the Universities of Central Lancashire, California and Sunshine Coast Australia.
“We want to use the plastic material in whole host of settings – in particular pothole fixing, which is kind of the bread and butter for what local councils do,” Mr Hall said.
“We’re going to test it on high volume A roads, rural roads, roads on industrial estates that get huge amounts of HGV traffic. And we want to stick it on the highest roads in England, the coldest and those that are prone to flooding,” said Mr Hall.
In each case, the plastic pellets will come from MacRebur, which is the sole producer of road plastic mix in the UK.
Company boss Toby McCartney’s inspiration for plastic roads can be credited jointly to his daughter and time he spent in India.
“I remember attending my little girl’s school assembly. The kids were asked the question ‘What lives in the ocean?’ When my little girl was asked she said ‘plastic, miss’,” McCartney remembers.
Pondering how to improve the environment for his daughter, McCartney cast his mind back to his time in India.
He remembered seeing locals filling potholes with landfill plastic, dousing it in diesel and setting it alight so that it melted and expanded to fill the hole.
“I thought, ‘That’s brilliant – that’s what we should do in Dumfries and Galloway.’ But it turned out that the council kind of frowned upon lighting things up in potholes,” he said.
So he set about finding a more palatable way to mend potholes – based on the same principle.
After literally hundreds of attempts, boiling pot after pot of carrier bags, bottles and bread bags on the stove Toby and his two co-founders finally found a plastic formula that worked and used it to pave his driveway.
Hundreds of combinations
“We went through more than five hundred different combinations of polymers, mixing them together before we found one that actually worked,” McCartney says.
That was just three years ago. In addition to Cumbria, a further 13 councils, including in Edinburgh, Glasgow, London and Cornwall are at less advanced stages of trialling MacRebur’s mix.
“Enfield has used the ‘plastic road product’ in two trials…both of which are performing well to date,” said Councillor Daniel Anderson, of Enfield council in London.
“We are considering using more plastic on our roads and our experience so far suggests that other councils could well benefit from using this product in their roads as a way of diverting waste from landfill,” he added.
Retailers have also shown an interest in repaving their premises with plastic. Tesco has used a mix of its plastic waste, made up by MacRebur, at two of its car parks, with similar moves by Morrisons, B&Q and McDonald’s also on the cards.
And MacRebur has exported its plastic pellets for trials in countries such as Canada, Russia, Turkey, Australia and New Zealand.
Even before these pellets set off for the other side of the world, they’ve been on a long journey.
Standing amid enormous piles of plastic waste, forklift trucks, overhead cranes and conveyor belts at a pellet producing factory in Dumfries, McCartney talks me through a lengthy process that begins when households chuck away their plastic in the bin.
This is collected by the local authority and taken to a waste sorting facility to be separated into different materials, he says.
Plastic waste that would otherwise be burned or buried is delivered to another sorting facility, where pieces that are suitable for roads are picked from a conveyor belt.
These are crushed and sorted into bales and delivered to the pellet-producing factory, where we’re standing.
The plastic is then cleaned, put through a shredder, cleaned again and shredded into a smaller size.
It is then dried and put into an extrusion machine which turns it into pellets.
The pellets are delivered to the asphalt manufacturer, and on to the road contractor, which puts in on to the roads. And so it is that the motorists of Cumbria will be driving over nappies, water bottles and carrier bags without seeing any difference.