Does any driver in the world not know the woes of potholes, they can damage your vehicle, lead to accidents and are a problem for pedestrians and cyclists too, of course. The road where I live suffers, although a stern letter to the council a year ago that mentioned the safety of primary school children who walk their route to school along our road seemed to get us a total road resurfacing within weeks. Neighbouring streets with quieter residents seemed to have to wait a long time for their potholes to be filled, and only one got a resurfacing, and that was done to a much lower standard than ours.
You can probably, tell it's an issue that raises my hackles and so it was no surprise that I was drawn to read a recent article in The Economist, flagged on twitter under the headline "How nanoparticles and microwaves can fix potholes quickly and effectively". Well, you would, wouldn't you?
In the article, 11th June 2016, online, but from the print edition), the always anonymous author of the piece reports that 16 million US drivers have suffered damage due to potholes in the last five years, ranging from punctures and bent wheels to damaged suspension; the mechanics' bills amounted to some $3 billion per annum. The estimated cost of making good all those roads is probably inestimable, although a figure for Britain has been put at 12 billion pounds (about $17 billion).
There is worse news in India, perhaps not surprisingly. About 3000 people die each year because of incidents caused by road damage in the form of potholes, the magazine reports. One has to assume that these kinds of accidents are actually widespread throughout those parts of the world where there are roads and people drive.
Incidentally, as an aside a start-up company is mapping the world with groups of three words that can substitute for a postal address (something 4 billion people lack entirely). Their program - what3words.com - applies a unique word triplet to every 9 square meter point on the Earth's surface. As an example address the front door of the Materials Today office is "stereos.pods.pimples", which then gives you the link: https://map.what3words.com/stereos.pods.pimples. This novel addressing system will be useful in so many ways for democracy, security, postal and others services, healthcare, disaster recovery and potentially even pothole and other road repairs.
Now, back to the main thread of my story. What is it that can be done cheaply and quickly and at low cost to fix those countless potholes, particularly those where the loose chippings that are thrown up might cause injury to children, pets on the street and adult kneecaps and damage to oncoming vehicles?
The Economist item suggest the answer lies with a magnetic additive included in the bitumen recipe used to bind the aggregate that underlies the material used to coat a road. Potholes usually form when damage to that outer layer by constant vehicle use, hard cornering, speeding and heavy braking damage its otherwise waterproof surface allow water to enter and then either through ongoing wear and tear or the freeze-thaw cycle of winter further break open the road to make the pothole grow.
However, if ground iron ore, which contains nanoscopic particles of magnetite, is added to the asphalt, then ferromagnetic resonance triggered by irradiation with microwaves causes localised heating - to the boiling point of water - can be used to rebind the surface when the pothole is filled and tamped down. This should preclude the formation of a secondary pothole from the edge of the repair, a common sight with conventional patching. The approach is being developed by Larry Zanko and his colleagues at the University of Minnesota Duluth, the magazine reports. This could make good all those potholes we need to fill.
But, what if pothole formation could be prevented in the first place that would improve safety on our roads, cut the repair bills and save lives? Etienne Jeoffroy of ETH Zurich, Switzerland, is working on a similar nanoparticulate additive that could be used in the initial surfacing of the road to create a tighter seal through a magnetic heating effect field. An annual rollover with a magnet-carrying truck would refresh the surface without the need for a costly and energy-demanding full on bitumen repair.
Any such approach will have to be widely tested and safety inspected, of course, and then there is persuading the road repair authorities to adopt the technology. It could be an uphill struggle made all the more difficult by potholes. Roll on the nanoparticle maintenance program.
David Bradley blogs at Sciencebase Science Blog and tweets @sciencebase, he is author of the popular science book "Deceived Wisdom".