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The road to hell is paved with asphalt
- groseje 3y agoWell, some of those reasonings are only true when asphalt is not layed and maintained properly. The same argument can easily be made for cobble stones. Have you ever seen a cobble stone road that is not maintained properly? Oh my… I invite the author to travel to a not so developed country. I agree on the conclusion, though, in an ideal world that both infrastracture is maintained perfectly, they should both be used in a city. Perfect example? Amsterdam.
- carlob 3y agoEven when it's a reasonably developed country (Italy) and when they are spanking new cobblestones can get slippery when it rains, they are noisier, and they are absolutely horrible on a road bike.
- toast0 3y ago> Have you ever seen a cobble stone road that is not maintained properly? My favorite is poorly maintained asphalt over cobblestones (which may or may not habe been poorly laid themselves)
- cyberax 3y agoThis is a completely misleading site. On one side you post a picture of a road with high traffic, and on the other side you post a mostly-pedestrian street. Of fucking course asphalt will look more damaged. If you try to use Roman roads for buses and trucks, they'll be destroyed completely within a couple of years (road damage scales as the fourth power of the axle weight). Cobblestone is also slippery when wet or iced. Paving stones might look nice, but they can get dislodged, or the road can warp if drainage is not done properly. Everything in engineering is a trade-off. You can use concrete for paving and for a small neighborhood road it'll last for decades with little maintenance. But it's much more cost-effective to use asphalt on a gravel bed, and just periodically do spot repairs. As asphalt becomes more expensive with the winding down of fossil fuels, we'll switch to more concrete roads. But we sure as hell won't be using paving stones.
- maicro 3y agoI like your general comment (nothing against the others of course, but your point about engineering trade-offs is always important to keep in mind), so I'll throw this note here: As far as I understand it, asphalt is also highly recyclable. https://www.researchgate.net/publication/344252166_Asphalt_Pavement_Industry_Survey_on_Recycled_Materials_and_Warm-Mix_Asphalt_Usage_2019_Information_Series_138_10th_Annual_Survey https://www.researchgate.net/publication/344252166_Asphalt_P... , referenced from the Wikipedia page about "Asphalt concrete" (https://en.wikipedia.org/wiki/Asphalt_concrete https://en.wikipedia.org/wiki/Asphalt_concrete ), includes this quote in the abstract: "The asphalt industry remains the country’s most diligent recycler with more than 99 percent of reclaimed asphalt pavement being put back to use."
- lucasmullens 3y ago> 99 percent of reclaimed asphalt pavement being put back to use Can't that be interpreted as them just not reclaiming asphalt they can't reuse? Genuinely asking, since things like this are often optimally worded for good publicity.
- maicro 3y agoFair point, and I don't have enough background to really answer that. I'll look for any information on "reclamation" rates of asphalt - there's got to be some amount that's just lost in general (ground up into fine particles that blow away, fall into drainage systems, etc.), and places where it's just not reasonable to tear it up to bring to a recycler vs. dump it somewhere convenient, but it does _sound_ like they are pretty good about reclaiming and recycling it. The next chunk in the abstract I quoted is: "The average percentage of RAP used in asphalt mixtures has increased from 15.6 percent in 2009 to 21.1 percent in 2019. In 2019, the estimated RAP tonnage used in asphalt mixtures was 89.2 million tons. This represents 4.5 million tons (24 million barrels) of asphalt binder conserved, along with the replacement of more than 84 million tons of virgin aggregate." That gives some context as to how much is actually being reused.
- traviswt 3y ago
- Narann 3y agoI suspect asphalt has some important gains on the security side, especially with ABS. I’m surprised security is not discussed at all here.
- InitialLastName 3y agoMaybe I'm being thick, but security in what sense? That someone could rip up pavers?
- altairTF 3y agoIn the sense of getting grip when braking
- maicro 3y agoI think they meant the "safety" use of "security" - ABS is most likely "anti-lock braking system", which per Wikipedia (https://en.wikipedia.org/wiki/Anti-lock_braking_system https://en.wikipedia.org/wiki/Anti-lock_braking_system ): "An anti-lock braking system (ABS) is a safety anti-skid braking system used on aircraft and on land vehicles, such as cars, motorcycles, trucks, and buses.[1] ABS operates by preventing the wheels from locking up during braking, thereby maintaining tractive contact with the road surface and allowing the driver to maintain more control over the vehicle." If I understand both correctly, the implication is that asphalt provides a better (safer / "more secure") grip with vehicle tires, including when ABS kicks in. This is backed up by other comments here talking about how other road surfaces, especially cobblestones, are very slick in rain and even above certain speeds. So yeah, slightly weird usage of "security" but it does make sense with a bit of context. Have a good day, all.
- Gare 3y agoThey mean safety, like skidding or breaking distance.
- pimlottc 3y agoThis is actually a concern for crowd control. Look up articles about old time street riots, like the Civil War Draft Riots, and you will find mentions [0] of crowds armed with "brick bats": > At 4 P.M. on July 13, "the children numbering 233, were quietly seated in their school rooms, playing in the nursery, or reclining on a sick bed in the Hospital when an infuriated mob, consisting of several thousand men, women and children, armed with clubs, /brick bats/ etc. advanced upon the Institution." "brick bats" means chunks of paver stones and bricks, typically pried out of the street, used as improvised projectiles. 0: https://press.uchicago.edu/Misc/Chicago/317749.html&title=The+New+York+City+Draft+Riots+of+1863&desc= https://press.uchicago.edu/Misc/Chicago/317749.html&title=Th...
- rconti 3y agoAsphalt is QUIET, at least when new. Of course, it can be poorly done, too. US101 in Silicon Valley through ~San Carlos is a dumpster fire every time it rains. They spent a decade repaving the damn thing, and now in each rainstorm massive potholes are generated. It's like a slalom course out there right now. This after the "repairs" from last year when dozens of cars got flat tires and bent wheels on the same day, after hitting massive craters.
- boldlybold 3y agoThis section of 101 consistently amazes me. It's only rain, and it degrades faster than the highways in the Northeast where I previously lived. Is it a particularly bad recipe of asphalt?
- rconti 3y agoIt's super wavy up north of 92, too. Worse after the repave than it was before. I'd guess part of the excuse is it's likely some kind of fill since it's so close to the bay. But I don't have any memories of it having these problems before the extensive repave in the 2008-2014 timeframe. I think there's gotta be something wrong with the asphalt mix, yeah.
- pushcx 3y agoThe Appian Way does not permit heavy trucks. Road damage increases to fourth power of vehicle weight. https://en.wikipedia.org/wiki/Fourth_power_law https://en.wikipedia.org/wiki/Fourth_power_law
- queuebert 3y agoThat is an amazing empirical fact. As a physicist, my mind goes to something like the acceleration of the acceleration (jounce), but I can't find a model for what is being observed.
- ndriscoll 3y agoI know next to zero material science, but I would think there's not much motion going on, and that it's more that once you're past the yield strength, stress causes nonlinear increases in strain, and you get hysteresis (i.e. permanent deformations). Then over time those deformations add up to a weaker structure that eventually fractures. As long as you stay within or close to the linear regime, there's little to no permanent damage. I imagine it's more of a chemical process (i.e. you're damaging the bonds/lattice structure of a material), but I don't know.
- Balgair 3y ago> the acceleration of the acceleration (jounce) Amazing. I had always learned it as the snap. Learn something new every day https://en.wikipedia.org/wiki/Fourth,_fifth,_and_sixth_derivatives_of_position https://en.wikipedia.org/wiki/Fourth,_fifth,_and_sixth_deriv...
- lifestyleguru 3y agoIncreasing every vehicle weight by over 500kg by adding batteries, increases the road wear by... at least 4 times for a subcompact.
- hinkley 3y agoI haven't been seeing electric vehicles weighing 500kg more. Closer to 500lbs more. Offset by the drivetrain. Increasing vehicle weight by about 15% would be 75% more damage per passenger vehicle. Which is not nothing, but for comparison, those 5000 pound trucks are doing almost 8 times as much road damage as a midsized sedan by weighing 2/3 more. But let's say you're right and the sedans weigh 30% more instead of 15% more, then it's about 2.8x the damage of an ICE. Trucks are still doing more damage than 3 battery electric vehicles. Honestly the weight of these things needs to come down over time. But you need infrastructure to do that. Lighter batteries don't just materialize out of thin air. Getting battery weight down increases range. Which can either make a car with better range, or let you shrink the battery another 5%.
- mminer237 3y agoI'm confused about how cobblestone gets plowed? From my observations, a large portion of asphalt damage occurs from snow plows catching on cracks or patches. I can't really picture it working on such a rough surface, but I'm not an expert. Do they just leave a layer of ice everywhere? Do they douse it in crazy amounts of salt? Is this just another idea that only works in warm coastal climates? I've always thought thick concrete was the higher-investment alternative.
- Scarblac 3y agoSalt, probably.
- margalabargala 3y agoSalt doesn't work when it's 10F and you get a foot of snow.
- jandrese 3y agoDoes Greece/southern Italy get enough snowfall to even have plows?
- margalabargala 3y agoBased on the discussion in this arbitrary internet forum, it sounds like if cobblestones do get plowed, it's by a specialized plow blade, operated by someone experienced, and they don't plow all the way down to the ground: https://www.plowsite.com/threads/downtown-cobblestone-streets.65989/ https://www.plowsite.com/threads/downtown-cobblestone-street...
- bee_rider 3y agoHaving grown up in the Northeast US and only visited the South as an adult, the appearance of smooth, sun-bleached, old looking asphalt was wild. Whole stretches far as the eye can see, with no potholes and minimal patching. It is actually a little disorienting. The signal of “this is not a well maintained road, you are probably heading away from the population center” is no longer provided. Anyway, hopefully that was an amusing anecdote. The real point is that there are whole regions that don’t care about plowing I guess.
- anonzzzies 3y agoAshpalt and especially some types of it (zoab), are far superior when people drive 2000 kg+ block of stuff (a car) at 120km/h through rain.
- Zak 3y agoAs a cyclist, cobblestones, which this article advocates are terrible.
- alistairSH 3y agoEvery day is Paris-Roubaix. Sounds fun... for a week.
- qwertox 3y agoI broke both of my hands because I slipped while cycling on wet cobblestone.
- peteradio 3y ago[flagged]
- bastawhiz 3y agoAs a motorcyclist, cobblestones can be deadly. It's basically impossible to make a road out of cobblestones safe if you intend traffic to move above 15-20mph. The absolute audacity of the article to ask "Where would you rather take your wedding photos?" I don't know, not on infrastructure built for moving large numbers of people? Go find a meadow or something!
- lxgr 3y agoExactly. I physically felt the image to the right in sections 4 and 5 in my wrists. 2, 6, and 7 share many of the same benefits and some of them are used for cycle paths in some places I've lived in.
- IshKebab 3y agoYeah I don't know how anyone could seriously criticise asphalt because ripping it up makes it less smooth, but then suggest cobbles as an alternative! Clearly they have only ever walked on cobbles or seen them in photos. It definitely is ugly though.
- GordonS 3y agoHell, as a motorist, motor cyclist or pedestrian, cobblestones are also terrible!
- andrewla 3y agoFrom the article: > Modular materials also tend to reduce traffic speeds, since [they] create a surface that is not as seamless as fresh asphalt or concrete. In one brick installation project, the average speed dropped from 41 mph to 29 mph. This represents 30% decrease in speed, and the risk of death when a pedestrian is hit by a vehicle is approximately 4x higher at 40 mph versus at 30 mph. I mean ... this pretty much says it all? For the vast majority of roads this is simply unacceptable. The main reason asphalt is used is that during its effective lifetime, the road surface is smooth and even.
- Macha 3y agoInside cities? 50kph (30mph) would be the highest speed limit within city limits where I am. 30kph (20 mph) is typical.
- marcosdumay 3y agoMore importantly, there's no measurement of those supposed safety gains at all. Brick roads are known for making cars lose control and forcing sudden changes in direction.
- LeifCarrotson 3y agoA reduction in speed of 12mph is unacceptable to drivers, but a 400% risk of death is unacceptable for pedestrians.
- chunha 3y agoThis site is weird, interesting topic but feels like comparing apples to oranges. We use imperfect materials because its the best trade-off on a number of factors
- AceJohnny2 3y agoYeah no. You know it's bullshit when they lead with the classic "Appian Way" comparison. Even more hilarious, comparing it with an area that gets snow! Sure, the Appian Way has lasted thousands of years, but that's because it's in a moderate climate, that never freezes, on stable ground, and with (very) light traffic. Author has no civil engineering background. But if all they wanted was to ragebait, success!
- throwway120385 3y agoThe other hilarious comparison is showing a picture of an asphalt laying machine that can do miles and miles of it per day next to a picture of a guy pounding a cobblestone into a garden path with a hand tool. At least do a proper comparison: https://pavetool.com/collections/optimas https://pavetool.com/collections/optimas
- TheCoelacanth 3y agoIt also didn't last thousands of years. Most of the road that's still in use was a parallel road built in the 1700s. The sections of old road that are usable have been completely rebuilt. Some sections of the old road that haven't been completely rebuilt near Rome are tourist attractions and they aren't remotely driveable by a car.
- timw4mail 3y agoConcrete is a more realistic replacement, although it has some of the same disadvantages. Pavers are not practical on anything but low-traffic, pedestrian, historical, or vanity roads.
- anon291 3y ago> We need to stop planning project primarily by spreadsheets, where the dominating inputs are costs you can measure easily. There are factors that are not reflected in those calculations that not only affect the quality of the place you're creating, but also the financial burden that the community will have to bear for decades down the line. Completely agree. Building a rocket? Plan by spreadsheet. Building a computer system for a data center? Definitely plan by spreadsheet. You know what those two things have in common: no one has to see them. Things that are in public, like streets, bridges, and facades, ought to not just be cost effective. They ought to be beautiful.
- bluGill 3y agoAsphalt is the cheapest we have. Even amortized over centuries it still turns out cheapest for many roads. While it doesn't last as long as alternatives, replaces it is very fast/cheap with modern machine and so replacing it every 15 years is cheaper than something that would last for 100 years. Of course this depends on what the road is used for. Most streets don't get a lot of traffic though, and so the cost curves work out to favor asphalt over time. Roads with a lot of traffic (particularly truck traffic) should be concrete as the cost curves work out better. Modular pavers that this article recommends are the most expensive. They don't lend to easy/cheap automation to replace and so there is a high maintenance cost.
- timw4mail 3y agoI'm still surprised how many freeways are asphalt, when it leads to road construction and lane closures every few years.
- gs17 3y agoI'm not too surprised as long as the initial cost is less than concrete.
- pixl97 3y agoMost things like interstates are actually concrete highways with an asphalt overlay giving the best of both worlds. Concrete is noisy, insanely so. Having asphalt over concrete gives a much smoother and quieter driving surface. Also most repaving of this type of road involves a rolling lane closure these days. They'll setup and operation generally at night that reclaims the old asphalt, sweeps the highway, sprays down a new sealer and then covers with new asphalt in a single convoy. When you have actual lane closures for any amount of time it has little or nothing to do with asphalt/concrete itself but actual infrastructure repair of the subbase.
- stonogo 3y agoAsphalt roads cost about half as much as concrete roads to build, and are vastly easier to maintain (you can resurface asphalt, while concrete requires slab replacement).
- jszymborski 3y agoI don't know if the results are replicable, but the idea of using algae as a binder for a bioasphalt seems super neat https://imt-atlantique.hal.science/hal-01204741/file/Audo2015.pdf https://imt-atlantique.hal.science/hal-01204741/file/Audo201...
- fgdelcueto 3y agoI used to live near a high-traffic road that was built with cobblestones. It probably had decades of having been built and it was horrible. I conjecture that due to soil expansion due to changes in moisture (no snow, but periods of dry and rain seasons), and therefore, the road was very bumpy (think of multiscale bumps) and it was extremely uncomfortable to drive on it. Everybody talked about how much they hated that road, but there were no good alternatives. I think the author underestimates the amount of warping in the underlying soil in some places. I'm sure it isn't a one-size-fits-all solution, but I agree it should be considered for suitable places.
- r0ckarong 3y agoThe author has never driven anything on cobblestones.
- Tade0 3y ago> Meanwhile, brick and cobblestone roads can last 150 years or more Unless of course you put bus traffic over them, which creates ruts and generally warps the surface. I live in a city where some roads are laid with cobblestone without good reason. They're: -loud even at low speeds. -shaky. -unsafe, as your braking distance will be significantly higher.
- NKosmatos 3y agoI have an idea on how to solve the asphalt degradation/cracking problem, that would keep all roads like new, but it requires an enormous power source. It involves lasers (lots of them) mounted on the front of a heavy vehicle/paver, melting the asphalt as it moves and simultaneously "ironing" it. If anyone has an idea for a really compact nuclear power source, contact me to discuss it ;-)
- fragmede 3y agowhat do you think about antimatter-dilithum reaction engines?
- NKosmatos 3y agoBeing a sci-fi fan (and a trekkie), I've thought of all the exotic power sources we could have, but unfortunately in our universe we have strict physical laws. SMRs (Small Modular Reactors) on the other hand are very much real and I hope in a few decades will be more practical for all sorts of things, including my laser-paver :-)
- pixl97 3y agoSo they actually have attempted machines that do this with more conventional power sources that heat/microwave the in place bitumen. Unfortunately from everything I've seen it doesn't work well because the aggregate mix becomes from the bitumen mix without mechanical mixing and the surface of the material is weaker and gets bumps faster. When they repave a road they rip up the old material and take it to the mixing plant where it's remixed in with new material, no nuclear reactor needed.
- krunck 3y agoAsphalt exists because bitumen is a cheap oil industry byproduct. If we stop processing massive amounts of oil(as will happen soon) the source of bitumen will dry up. What then?
- bumby 3y ago>If we stop processing massive amounts of oil(as will happen soon) What makes you think oil processing will decline soon? It seems like we have an ever-increasing appetite for the stuff (with a possible exception in Norweigan production) [1]. [1] https://ourworldindata.org/grapher/oil-production-by-country https://ourworldindata.org/grapher/oil-production-by-country
- TriangleEdge 3y agoGrew up in the east coast of Canada where we have frigid winters. There's popular knowledge there that water will seep unevenly under the road, freeze, and lift parts of the road up. This causes the road to crack. Given snowplows scrape the roads, and cars still drive during winter, the lifted pavement gets damaged. This eventually results in potholes. Pavers don't work because the city needs to remove the snow, and the pavers would get removed by the plows. I don't know of a viable road alternative that is also economical for places with snow.
- Khelavaster 3y agoHow does this guy feel about concrete, I wonder...