This 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.<p>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.<p>Paving stones might look nice, but they can get dislodged, or the road can warp if drainage is not done properly.<p>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.<p>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.
The Appian Way does not permit heavy trucks. Road damage increases to <i>fourth power</i> of vehicle weight. <a href="https://en.wikipedia.org/wiki/Fourth_power_law" rel="nofollow">https://en.wikipedia.org/wiki/Fourth_power_law</a>
Well, 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.<p>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.
Asphalt 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.<p>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.<p>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.
I 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.<p>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.
Concrete is a more realistic replacement, although it has some of the same disadvantages.<p>Pavers are not practical on anything but low-traffic, pedestrian, historical, or vanity roads.
Grew 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.<p>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.
I'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?<p>I've always thought thick concrete was the higher-investment alternative.
I 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.<p>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.<p>If anyone has an idea for a really compact nuclear power source, contact me to discuss it ;-)
This 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
> 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.<p>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.<p>Things that are in public, like streets, bridges, and facades, ought to not just be cost effective. They ought to be beautiful.
Asphalt is QUIET, at least when new.<p>Of course, it can be poorly done, too.<p>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.
> Meanwhile, brick and cobblestone roads can last 150 years or more<p>Unless of course you put bus traffic over them, which creates ruts and generally warps the surface.<p>I live in a city where some roads are laid with cobblestone without good reason.<p>They're:<p>-loud even at low speeds.<p>-shaky.<p>-unsafe, as your braking distance will be significantly higher.
I don't know if the results are replicable, but the idea of using algae as a binder for a bioasphalt seems super neat<p><a href="https://imt-atlantique.hal.science/hal-01204741/file/Audo2015.pdf" rel="nofollow">https://imt-atlantique.hal.science/hal-01204741/file/Audo201...</a>
Yeah 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!<p>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.<p>Author has no civil engineering background.<p>But if all they wanted was to ragebait, success!
From the article:<p>> 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.<p>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.
Asphalt 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?