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A transportation engineer has a simple solution to potholes: pave better roads
- axaxs 9y agoI've always read that road damage was caused by heavy vehicles(semis) which stress fracture the roads, which in turn fill with water, freeze, expand, rinse and repeat. This article seems to imply it's caused by the road design itself, though. Wonder which is true (or both)?
- throwawaylalala 9y agoWe have potholes in Florida. No freezing.
- cmontella 9y agoBut we don't really have potholes in CA, at least not the quantity and quality that I experienced living in PA. It's a minefield there right now, so I would imagine freezing is part of the problem, or at least exacerbates it.
- mgberlin 9y agoI live in Santa Cruz CA and and deal with terribly potholed roads. The air temperature here rarely gets below freezing, and I've never seen any ice on the roads to indicate that the ground temperature has been below freezing. Clearly something besides the freeze/thaw cycle is causing potholes.
- tigershark 9y agoWhat? I never seen worse road in my life than in LA..
- wlll 9y agoIs that because in LA you have time to scrutinise in depth a great deal of tarmac? ;)
- haldean 9y agoYou must have never taken a bike down Market Street :)
- denimnerd 9y agorain will do the same thing though.
- woliveirajr 9y agoPut water inside the hole, run over it with a car that will put some pressure on it, and it'll fill all those small cracks inside the asphalt. Repeat many times. Also, asphalt isn't solid, it get thinner when the sun is high, deforming every time a car runs over it in the summer. South of south America, more or less equivalent to Florida: no freezing during winter and not that hot during summer, but everytime there's many rainy days, holes will appear. Get few days of hot sun and the roads will deform a bit, specially where trucks and buses run over.
- tarmon 9y agoJust want to point out that it's asphalt, not asfalt. :)
- MisterTea 9y agoNo, it's ashfault. Though, I don't know what he did exactly.
- yousir 9y ago> South of south America, more or less equivalent to Florida Are you calling North America "America", and then go on and call Florida "south America", as if there isn't such a place in the world as South America? I do not approve of this North America-centric view of the world at all.
- mc32 9y agoSouthern would work better than south. Proper place names which have cardinal pints in their names typically will use South and not Southern. So we have South Africa, South Australia, South Dakota. But southern California, southern South Dakota, etc.
- mitchty 9y agoAmerica refers to The United States of America. Same as we don't refer to Mexico all the time as Estados Unidos Mexicanos. I don't approve of getting upset over turns of phrase online. Principle of charity.
- jack9 9y agoMere existence can't be eradicated. There are multiple issues. The existence of them (forgone), the frequency of their appearance and growth lifecycle. Changing any of those things, affects the maintenance problems.
- cbhl 9y ago[edit: removed]
- imglorp 9y agoPA is notoriously bad at coordinating tearing up with other work. It seems that 1ms after a clean paved road is down, someone in another dept is plotting to tear it up to get at their utility, then hire 2 guys with a shovel to do a very halfassed patch job afterwards, which either is heaved up high or sunk down low. The halfassed patch will become a pothole for the next 10 years of repatching it badly over and over again.
- megaman22 9y agoUsually it's badly designed road bed underneath. Many roads don't have a proper foundation underneath, so unless that is fixed, just repaving them is a stopgap measure, and it just starts cracking and subsiding in the same places it was bad before.
- CoffeeDregs 9y agoFrom the article: Conventional wisdom suggests that cracks begin deep in the roadbed and gradually migrate upward, eventually breaking out on the asphalt surface. Not so, claims Halim. The cracks have already been created by the rollers, regardless of the temperature and asphalt mixture used. I would guess that the mechanism of action is that water gets through the cracks and erodes the underlayment.
- marcosdumay 9y agoWell built roads can stand heavier vehicles. If you either run too heavy vehicles, or build your roads badly, potholes will appear.
- Maybestring 9y agoRoads are designed, manufactured, used, and maintained. You can impact road surface wear by tweaking any of these variables. They all affected the surface, there is no single cause.
- lucas_membrane 9y agoIn rainy and hilly places, doesn't water flow under the roads from the sides, making little caverns beneath the pavement that collapse? In hot climates, doesn't heating and cooling from the sun create the cracks. In cold climates, doesn't expansion of ice as it freezes create the cracks? Back 35 or 40 years ago, Phillips petroleum was promoting a paving material that supposedly solved this problem. Where is it? There may be single causes, we just need them all to marry single solutions.
- jaclaz 9y ago>I've always read that road damage was caused by heavy vehicles(semis) which stress fracture the roads, which in turn fill with water, freeze, expand, rinse and repeat. This article seems to imply it's caused by the road design itself, though. Wonder which is true (or both)? In my experience, both. Set aside for one moment this new roller, the reality is that road paving is not exact science, and - even if it was - it is largely executed badly. Paving (and before paving the underneath layers) are more like "cooking" than everything else. It is not like you have the right recipe, good ingredients and follow "instructions" accurately you can replicate some dishes. Usually (of course it greatly depends in local uses and materials available) the first mistake is under-calculating the thickness and consistence of the bottom layers (gravel, sand, quarried rubble, sometimes mixed with cement or lime). The second one (again usually, not always) is inadequate protection from running water (be it coming from rain or from the soil). Then it comes the exact composition of the asphalt, the (right or wrong) type and quantity of bitumen, the temperature at which it is mixed, transported and layered, the amount of compacting, etc., etc. In the last 20 years or so some great betterings have come from the use of reinforcing layers, both in the underpavement (woven or non-woven geotextiles) and in the asphalt itself (geogrids, usually plastic). Whilst geogrids in asphalt are rather costly (both as material and additional work to lay them), high strength geotextiles are relatively cheap and it is surprising how - still today - they are not widely and universally used. Both however are only good for highways and roads outside the city, as the benefit of these textiles is to spread as much as possible any dynamic action provoked by heavy traffic and loads onto the widest possible surface, but in urban contexts the surface (and up to 1-1.5 m depth) is "ruined" by every kind of duct, pipe, cable and other services, often re-cut (over and over) for maintenance/repair/replacement.
- shmageggy 9y agoI've always wondered why we still have such crappy roads, given that roads are possibly the oldest technology there is, and every civilized place on earth has paved roads, thus making an enormous potential market for a better solution. Either: 1) Most people don't care as much as I do about the bone-jarring, car-ruining potholes that are ubiquitous in every cold climate on earth, and thus aren't willing to spend their tax money on fixing it, or 2) Engineering a better road is simply too hard of an engineering problem, so what we have is the best we can do at the moment. Or equivalently, any better roads we do know how to make are too cost-prohibitive. Maybe I'll forward this article to my local representatives.
- lubesGordi 9y agoI was always under the impression we have crappy roads because of planned obsolescence. Basically we have crappy roads because we need to employ union workers to fix them. So the $50 million we save not fixing crappy roads is basically $50 million out of the union income, which impacts elections. I don't know if this is actually the case, but it seems plausible.
- daveguy 9y agoWell... We have been engineering better roads. Compared to brick or packed earth, asphalt is high tech. New materials and mixes are researched and tried. Some recent roads seem to have lighter finish than traditional blacktop. You are right though, it is a cost vs durability issue.
- zhdc1 9y agoThis, by far. I can't tell you how many times I've had to listen to my significant other (a roadway engineer) talk about new types of asphalt designed to reduce noise pollution, last longer, or fulfil some sort of edge-case requirement. Surprisingly, for as bad as roadway construction is in the states (and it's absolutely awful), the US apparently leads the rest of the world in the study of roadway materials.
- DennisP 9y agoOr (3) the paving companies are happy with planned obsolescence, and the deciding customers are politicians who will move on before the new roads go bad, and won't be criticized anyway for authorizing the same methods everyone else uses. No individual involved has a strong incentive to make things better. Unless, of course, constituents start making an issue of it with their local representatives :)
- maxerickson 9y agoThe article calls the invention a paver but it is a compactor (what everyone calls a steamroller). This article is a little more sciency: https://canada.constructconnect.com/dcn/news/Technology/2017/3/AMIR-compactor-to-disrupt-asphalt-paving-by-keeping-roads-grounded-1022176W https://canada.constructconnect.com/dcn/news/Technology/2017... The paver is the machine that catches the asphalt out of the dump truck and spreads it across the road.
- FussyZeus 9y agoTook me awhile to figure this out as well, this isn't even a paver, it's a better roller. IMHO that just makes the difference it produces even more impressive, I thought this was a totally different paving machine.
- nategri 9y agoHaha I really expected the "pothole problem" to be some kind of mathematical conjecture. Nope, literal holes in literal roads.
- Yetanfou 9y agoSame here, especially with the original title of "a 30 year old machine that solves the pothole problem", gave me visions of a Commodore 64 doing something which could also have been done on a musical gift card nowadays (but isn't). Pity, really, physical pothole problems are so simple to solve...
- dang 9y agoOk, we've replaced the title above with a roadworthy sentence from the article.
- igor47 9y agoi assumed it would be literal holes in literal pots...
- zentiggr 9y ago> Nichols said the AMIR “has great potential” to extend the life of roads, and “save significant taxpayer dollars.” In 2016, an MTO analysis found that the province would save $50 million annually if roads on the MTOs highways could last even one year longer. And there you go... goes against the contractors' interests to use more efficient means, so this compactor's use will have to be mandated by city governments who want to avoid the political backlash of public awareness of wasted budget. Or in other words, good luck with that grassroots campaign.
- jonny_eh 9y agoIf the researcher was more entrepreneurial he could have started a competing road paving business. He may have made a lot of money doing it. I suspect he was too busy researching other stuff though.
- giarc 9y agoThat's a license play not a "I'm going to start a paving business" play.
- drspacemonkey 9y agoI wonder if that could be resolved by the government offering an annual bonus for every road that requires no pothole maintenance. If the bonus were bigger than the profit they'd make from filling in the pothole, it would be free money for the contractor + a savings for the government because they don't have to pay to fix something that isn't broken. Mostly, I wonder how different the world would be if there was an incentive to build things that don't break.
- pbhjpbhj 9y agoThere are plenty of incentives to build stuff that's resilient; usually financial profit is opposed to it, which I presume was your point.
- spodek 9y ago> “It’s not my fault it’s not being used, I’ve done everything a researcher can do,” El Halim said. What's wrong with much of traditional education summed up in one sentence.
- gitgreen 9y agoResearcher != Educator. There are countless researchers in colleges and universities around the world producing things(useful or otherwise) that don't teach a single class and only mentor grad students because they have to. And as somebody else mentioned he can't force others to use his technology.
- CoffeeDregs 9y agoI was literally wondering about this question the other day. It's 2018; we can make CPUs with 12nm features but we can't make a long lasting asphalt? Fascinating: Nichols said the AMIR “has great potential” to extend the life of roads, and “save significant taxpayer dollars.” In 2016, an MTO analysis found that the province would save $50 million annually if roads on the MTOs highways could last even one year longer. "The MTO is not planning on buying or specifying the use of AMIR asphalt rollers..." Might be of interest, too: http://www.dykespaving.com/blog/why-use-asphalt-instead-of-concrete/ http://www.dykespaving.com/blog/why-use-asphalt-instead-of-c...
- JustSomeNobody 9y ago> Asphalt resurfacing simply involves applying new asphalt over the old. Damaged areas are filled with fresh asphalt, and a steamroller goes over the entire surface to yield smooth, even pavement. Florida native, I can tell you this is very temporary. Big chunks will eventually come up and you can see the previous pavement underneath. I'm assuming that between the heat here and the cracks mentioned in the original article that let water seep between the layers, this is just a bad way to fix a road.
- allannienhuis 9y agoUp here in Canada, I've universlly seen them grind up the very top layer of the old asphalt before laying down the next layer. I presume that's to improve adhesion. Can't say I've seen many places where obvious delamination of the layers happens. Are they not taking that step in florida?
- brianbreslin 9y agoThis strikes me as a classic separation of buyer interests from vendor interests leading to misaligned incentives. The contractors have no incentive to update their equipment. In fact if this is scientifically proven to be a major solution they should want to avoid this. If the province could incentivize the vendor to pay them more for every year there is no pothole and punish them for every pothole they would totally adopt this tech.
- pg_bot 9y agoI would argue that lack of adoption is likely a discovery and design problem rather than an economic one. In a free market other people can choose to enter into the contracting business. If I have a leg up on my competition (paving better roads for the same cost) I will eventually out compete people who fail to adapt to the new method. This doesn't happen immediately, but you can't fool everyone forever if there truly is a better way of operating. This technology likely has not been adopted due to difficulty and expense of manufacturing a robust machine and lack of marketing. How many people even knew this solution existed? What is the measurable benefit to paving roads this way? How much does the machine cost vs traditional roller method? All of this work is expensive and there isn't a guarantee of success. While the hypothesis seems reasonable you have to do all the math/science to figure out if this truly is cost effective. Ideas are great, execution is hard.
- brianbreslin 9y agoGreat points. We don't know if he is manufacturing these pavers or licensing his tech to others. We also don't know how much more his are than the regular Komatsu or john deere ones. What if the vendors buy the existing companies because they provide superior service?
- goodcanadian 9y agoI suspect nobody is manufacturing these machines. Unfortunately, "Build a better mousetrap and the world will beat a path to your door," is completely wrong. It is one thing to develop a new technology, but another thing entirely to convince someone to manufacture, and another thing again to convince anyone to buy.
- sowbug 9y agoIf self-driving cars start to catch on, it seems that the standards for roads must improve. There are some roads in my area that could be an excellent Turing test. If you follow what the lane markers are telling you to do, you die and are probably a robot. If you ignore the markers and survive, you are probably human. I'd rather increase road standards and accelerate the evolution of self-driving technology than require the development of technology that is capable of driving on today's terrible roads. I know this is not a binary choice -- realistically, both would happen. But I don't think anyone's even talking about better roads for self-driving cars. If even just major roads had to be maintained to a minimally machine-readable standard, it would be a good thing for drivers -- whether human or machine.
- donatj 9y agoReminds me of this section[2] from "How Engineers Create the World" by Bill Hammack - an interesting but perhaps scattered read. Well, a pothole is not just a technological thing, it's also a political entity. Usually we think of European nations as steeped in governmental regulation, and the United States as a free market, but actually the opposite occurs in building roads. In the United States the government sets specifications and asks contractors to meet them. Once done with the road they have no more responsibility. Contrast this to France where the contractors must come up with their own specifications and guarantee their work. This means that if a pothole developers the contractor has to fix it. But in the united States, once the job is done, as long as it has met specifications, the contractor is no longer liable. 1. https://www.amazon.com/How-engineers-create-world-commentaries/dp/0983966109 https://www.amazon.com/How-engineers-create-world-commentari... 2. https://i.redd.it/uthzdyul53fy.png https://i.redd.it/uthzdyul53fy.png
- colanderman 9y agoReformatted for those on mobile: > Well, a pothole is not just a technological thing, it's also a political entity. Usually we think of European nations as steeped in governmental regulation, and the United States as a free market, but actually the opposite occurs in building roads. In the United States the government sets specifications and asks contractors to meet them. Once done with the road they have no more responsibility. > Contrast this to France where the contractors must come up with their own specifications and guarantee their work. This means that if a pothole developers the contractor has to fix it. But in the united States, once the job is done, as long as it has met specifications, the contractor is no longer liable. (Please don't use code blocks for quotations.)
- donatj 9y agoI like that you copied it typos and all ;) I retyped it from the screenshot on my way out the door at work and now note a number of mistakes.
- horsecaptin 9y agoContrast that to some other countries where the government comes up with minimum requirements, then asks for bids. One of the requirements is that the road comes with a 8 to 10 year warrantee - any fixes come out of the contractor's pocket. Contractors are pre-approved for their ability to execute.
- abacate 9y agoIt does not solve anything, just pushes the problem a little further.
- stevenwoo 9y agoI recall there was an article on the front page of hacker news not long ago that argued that it was a better use of public money to not pave every road and to let some roads just be dirt roads because the maintenance cost was not justified by the amount of road traffic. This was not the article but similar to it: https://www.wired.com/2016/07/cash-strapped-towns-un-paving-roads-cant-afford-fix/ https://www.wired.com/2016/07/cash-strapped-towns-un-paving-...
- detaro 9y agoThat's how it seems to work with smaller roads in northern Sweden. They have a surface which is kind of compacted sand/gravel, which isn't all that robust long-term but can't really crack and is very easy to fix: a specialized machine drives over it and basically breaks up the top layer, re-applies it and smoothly and compacts everything again, and the road is good again.
- webnrrd2k 9y agoI'm a bit suspicious of the claim that metal rollers cause substantial cracking, or at least enough cracking that this machine with special rubber belts would fix it. I have no experience with this, but it seems that hot asphalt is gooey and would flow enough to seal any cracks that are created during construction. Second, usually a top coat or slurry coat is poured on top of asphalt to seal the surface. I'd think that would seal up any cracks far more effectlvly than this new roller machine.
- jrs235 9y agoIn the North, it seems the interstates and highways tend to get cracks across the entire road at relatively even intervals. I suspect they form where they lay down the rebar supports/holders. It makes sense to me that cracks/"potholes" would form there as it seems that at that point compression of some sort would occur from the weight of vehicles causing the asphalt/road to crumble. While more work to initially build and lay... What would happen if they laid the supports and rebar down like elongated tile or vinyl siding on a house... Never having adjacent pieces ending near each other?
- glibgil 9y agoIt could also be from swelling of the rebar from salt and melting ice
- allannienhuis 9y agoI've never seen rebar on asphalt highways. Do they top the concrete highways with asphalt where you are?
- jrs235 9y agoYeah you're correct. They are concrete.
- phkahler 9y agoWait, you mean they put asphalt on the roads!?!?! More and more I see this step skipped and concrete cross-cut every 50 feet or whatever. Guess where the potholes form...
- hugodahl 9y agoI've often wondered, especially as I cringe, clench and brace as I encounter another pothole (or chasm) why this is still an issue? Particularly since there are very well known and enduring roadways capable of handling much heavier loads and stresses - specifically airport runways and taxiways. I can't recall ever seeing a runway shutdown abd inoperable for months on end due to "road work". I can think of a few reasons around why this isn't a thing, most of them being human factor (no money on building something I won't get paid again to fix later). The only "true" reason I can fathom is that runways are much more expensive to build. Order(s?) of magnitude more expensive. Am I way off the mark, or is there something I've clearly missed?
- tmm 9y ago> I can't recall ever seeing a runway shutdown abd inoperable for months on end due to "road work". I’m guessing you haven’t flown through Phoenix recently? They have had a runway closed for repaving (might be reopened now) since early January. Runways are generally concrete rather than asphalt and there are plenty of concrete highways. It tends to be a louder and less comfortable surface to drive on and when repairs do need to happen, they’re more disruptive than a simple asphalt resurfacing. I’m sure there are other reasons to prefer asphalt, but I’m not a civil engineer.
- fotbr 9y agoTwo years ago (maybe three?), they closed one of the runways at the local international airport for the better part of a year for repairs (and partial replacement). That particular runway was poured in the late 50s or early 60s, and last had major work in the 90s. So it happens, just not on the every-two-or-three-years schedule that it does for roads (or yearly, depending on where you are). The obvious difference, at least around here, is that runways are made of concrete - lots of it, each batch truckload tested as it is poured (slump tests, anyway), while roads are made from asphalt, as little of it as the DoT will allow, and as far as I can tell, zero quality control testing.
- mc32 9y agoI'm curious how this machine addresses seams in the roadway. Obviously this machine isn't 4-lanes wide, so how to they prevent potholes from forming between seams (often seams are aligned with lanes but they still end up allowing cracks to form.