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What are those dents in I-90 outside Seattle?
- modeless 4y agoI haven't seen these in a decade but I knew what they were talking about instantly. I used to wonder what they were all the time. I sure didn't expect to get an answer randomly on the HN front page. They did a really good job installing these. They look like they would be bumpy but I never felt them at all.
- frosted-flakes 4y agoSimilarly, I'm always impressed by how smooth the ashpalt highways in Toronto are, even though they are spiderwebbed with cracks absolutely everywhere. That's because the cracks are filled each spring with some sort of sealant. They make a regular slapping sound as the tires pass over them, but cannot be felt.
- lostlogin 4y agoI don’t think you could do the repair with asphalt. I’m not even sure I’ve ever driven on a concrete road, as down here in New Zealand there aren’t any I don’t think. The current repair practice is to pour tar on the asphalt road and then a coating of road gravel. It’s noisey, comes off when heavy vehicles use it, comes off with heavy usage or heavy breaking, comes off in hot sun and it’s utter trash. It’s cheap though!
- frosted-flakes 4y agoOf course they don't add rebar to asphalt roads, that would be ridiculous. The sealant process is done manually, with some poor sod pushing a machine along each crack and injecting hot sealant which prevents further water incursion and the associated frost heave. That's partly why I'm so fascinated with it: some sections of highway are cracked everywhere, with hardly a square metre that doesn't have a crack running through it, and yet they're extremely smooth.
- LegitShady 4y agoyou are describing an asphalt microseal over the entire road surface. they are describing sealing of cracks using asphalt "tar snakes". They address different problems. Road resurfacing improves stopping distances and rough rides if the road is overall in ok condition. If the road has large cracks in it this does nothing Tar snakes are used to seal cracks from water because after rain the movement of vehicles over the wet subgrade under the road creates a pumping effect that ejects subgrade material out from the cracks and causes potholes in the future.
- rootusrootus 4y agoWe have the same thing on our neighborhood asphalt roads. It's a noisy day every few years when they do it. One truck idles up the road with a big air compressor and a guy walking along behind it with an air nozzle on a stick, blasting anything loose out of the crack. It's pretty loud, predictably. Then a little ways behind him comes another guy with a tank of tar filling the cracks. Every few years on an alternating schedule they put a liquid asphalt coating over the top of the whole thing. It's not the most beautiful thing, but it's smooth. I'm 97.92% sure they don't actually do this because it's better. It's cheaper than resurfacing -- then they drive along with a big machine that grinds off the top few inches of asphalt, crushes it up, adds tar, and puts it back down to be rolled.
- julianlam 4y agoIt's funny how other commenters on HN are telling you what it probably is, even though they might not live in Toronto. To my knowledge, it isn't any special application of product. It's literally cheap asphalt they pour on top of cracks and potholes and pound it down lightly. The reason why it's surprisingly smooth is because a thousand plus cars have driven over it, flattening it down to road level. > "Crews place asphalt and rake it into the pothole. Then they tamp down the asphalt and smooth it out until the road surface is improved. The job takes 15-20 minutes." They do this because it is literally impossible to get to all of the potholes in spring. Want some neat stats? https://www.toronto.ca/services-payments/streets-parking-transportation/road-maintenance/potholes/ https://www.toronto.ca/services-payments/streets-parking-tra...
- vl 4y ago>They did a really good job installing these. It really depends on the car and suspension! In regular car driving over them is fine. In motorhome vibration is so strong that I go in the left lane, otherwise it's two hours of crazy shaking.
- modeless 4y agoThis was a decade ago. Perhaps the replacement concrete is wearing away now.
- mbauman 4y agoA little funny to not link to the comment that had the answer — they're dowel bar retrofits. https://en.wikipedia.org/wiki/Dowel_bar_retrofit https://en.wikipedia.org/wiki/Dowel_bar_retrofit
- haunter 4y agoIf a Wikipedia page about a technological topic (so not a person, place etc) has a very few languages available (in this case 2) then it always makes me wonder how other countries in the World solve the same issue. This seems like a very US thing for example but maybe I’m wrong
- Gordonjcp 4y agoThere's one bit of jointed concrete road that I know of in the UK, a few miles where I live on the A90 near Laurencekirk. It's bloody awful, like driving over smashed paving slabs. In my big old Range Rover with its off-road air suspension and massive reinforced tyres it's a noisy and uncomfortable couple of miles. In a modern vehicle with ultra-low profile tyres and incredibly stiff "sporty" suspension it must be like being rolled down a hill in old washing machine. So yeah it's entirely possible that it's a very US thing, I've never seen it anywhere else. Edit: here you can see a section, with repairs showing up as dark lines across it. https://www.bing.com/maps?osid=55db8ed6-35d8-4916-82c3-14131e11a722&cp=56.752882~-2.651094&lvl=18&style=a&v=2&sV=2&form=S00027 https://www.bing.com/maps?osid=55db8ed6-35d8-4916-82c3-14131...
- bombcar 4y agoThe US interstate moves insane numbers of huge ass-trucks that weight one billion metric pounds each or something. Anything less than airport-grade concrete dies instantly, and then dies again when it invariably freezes to -40° Kelvin, because fuck physics when shit gets cold.
- WalterBright 4y agoThe reason for the interstate trucks is the taxation system that punishes railroads for owning their right-of-way. The trucks cause by far the most damage to the highways, but taxpayers subsidize that with the gas tax. Trucks also do not pay property tax on the highways. Long haul freight should be done by loading the semi's trailer onto a flat car, and picking it up near the destination. Another myopic government decision is to try to replace the diesel trucks with electric ones, you know, for the environment. Far better for the environment would be to do away with long haul trucking and use freight trains instead, which are far more efficient. Trains also do not spread tire and brake dust all over the place, either.
- legitster 4y agoMan, reading this format does not make me miss forums. It's easy to opine for the "internet of old", but I for one do not miss having to post a car problem to a Ford Escort message board and maybe getting an answer after 3 days of being told I am an idiot.
- deleted 4y ago[deleted]
- lostlogin 4y agoNow you can get that response in minutes or even seconds, and in a more readable format with push notifications and advertising.
- sph 4y agoAnd people upvoting the one that called you an idiot and paying money to give them awards, to make things even worse.
- rootusrootus 4y agoThat happens, of course, but I still have a couple of forums I go to which get good traffic and have much better information and advice than the Reddit version.
- osti 4y agoI always thought it was to help with traction during winter... They are only present outside the city afaik.
- dbavaria 4y agoThey're present in the city too, here are some in Seattle: https://maps.app.goo.gl/2j5H4gEXKrRVFr469 https://maps.app.goo.gl/2j5H4gEXKrRVFr469
- jasonhansel 4y ago> Maybe they didn’t use the best grout and that’s wearing away faster than the surrounding concrete. IIRC this is one of the disadvantages of concrete (as opposed to asphalt) road surfaces: it's very hard to repair them in ways that don't degrade over time. edit: You can tell this road is "real" concrete because of the visible seams between each slab. For an ideal repair, they would have had to replace every affected slab of concrete, which is...all of them along this stretch. You don't see these concrete road surfaces much near where I live (in Boston), particularly because such roads are much less safe when snow and ice are present.
- thehappypm 4y agoInteresting. I’m GBA too. What are our roads made of?
- wyldfire 4y agoMost highways in the US that I've seen are either concrete or asphalt.
- Maursault 4y agoI don't understand how everyone knows what the commenter is referring to when it took me forever. I figured he was referring to the "dents" on the shoulder, which I thought were rumble strips.
- fckgw 4y agoIf you scroll up to the top of the thread the OP posted a little ASCII diagram of what they were describing
- teawrecks 4y agoPeople inferred what OP was talking about by reading the post. In addition to an ASCII diagram, it included the phrase: > I’m not talking about the perpendicular “rumble strips”
- carbocation 4y agoLike GP, I was also confused. I think this is because HN links to a comment featuring a streetview photograph. Until I saw your comment, I didn't really notice that the article should have been linked to the very first post in the thread, which does clarify the question.
- landr0id 4y agoI asked the WSDOT the same question a while back: https://twitter.com/landaire/status/944698354742599681 https://twitter.com/landaire/status/944698354742599681 "The dowel bars help extend the life of the pavement by about 10 years or so."
- unixhero 4y agoA forum! How refreshing.
- quickthrower2 4y agoLooks like a discourse.org one
- msla 4y agoUsed to be a vBulletin forum until Summer 2020.
- unixhero 4y agoAhh discourse... such a good engine. Only matcher by nodebb
- julianlam 4y agoThanks :) Hoping to surpass one of these days.
- mef 4y agowow, searching the thread is a nightmare. there's a non-native search panel that comes up with cmd+f, and you press cmd+f again to do a native browser search... and both of them don't actually search the thread, only the visible section. you have to scroll around to load all parts of the thread in order to actually search the whole thing, with either of the two searches!
- zerocrates 4y agoDiscourse's own search, the one that comes up first, is definitely supposed to search the whole thread, that's the whole point of it. Discourse does a lot of loading/unloading the page as you scroll on these big infinite-scroll threads so the native browser search would be not so useful, in the way you describe. I don't notice the Discourse one having any trouble searching the whole thread as advertised here though.
- idatum 4y agoOnly slightly related, about I-90 generally: A parent of mine who grew up and lived most of their life on the East Coast, US, visited and we drove east across WA. At one point they could not wrap their head around the fact that we had been travelling at around 80 mph for 2 hours. And it basically looked the same out the window :) The US West is huge.
- rootusrootus 4y agoThere are a number of areas out in eastern Washington where the state patrol doesn't often bother with speed enforcement and people routinely go even faster. It is common to have packs of cars going up the left lane over Manastash Ridge at closer to 100 mph. With a closure rate of about 70 mph on the trucks in the right lane. One way to make an otherwise monotonous drive more interesting.
- egberts1 4y agoDowel Bar retrofit. Details on how to make a set of dowel-bar-retrofits. https://dot.ca.gov/programs/construction/construction-manual/section-4-41-existing-concrete-pavement https://dot.ca.gov/programs/construction/construction-manual... Longitudinal grooving to achieve PIARC category of roughness and rolling resistance of an inverse to raised Cat’s-Eye and Botts’ Dots (“turtles” in Washington/Oregon, “buttons” in Texas). They are reflectorless, and are https://www.fhwa.dot.gov/pavement/pubs/hif17011.pdf https://www.fhwa.dot.gov/pavement/pubs/hif17011.pdf Not to be confused with Rumble strips which are also known as audible lines, sleepy bumps, wake up calls, growlers, drift lines, waker-uppers and drunk bumps.
- djmips 4y agoThere was a video posted in the comments as well. https://www.youtube.com/watch?v=ud5AdEPL16A https://www.youtube.com/watch?v=ud5AdEPL16A
- insane_dreamer 4y agoI didn't know what purpose they served but I can tell you they are nasty if you hit them with their bike at speed; almost had a serious accident when moving out of the lane and over to the narrow shoulder to let cars by me pass (this was on a small 2-lane road through a pass, not a highway of course), didn't realize how deep the dents were and almost lost control of my bike
- Webstir 4y ago[dead]
- x3n0ph3n3 4y agoThere are actually 2 different sets of "dents." On the side of the road are the rumble strips that you refer to. In the middle of the road, there are the dowel bar retrofits.
- naikrovek 4y agonot a rumble strip. the marks discussed are inside the lane.
- loeg 4y agoIf you read the linked thread, the commenters make it very, very clear that they know what rumble strips are and are not talking about rumble strips.
- Illniyar 4y agoThe google maps embedded in comment 30 is slightly disturbing. If you click the chevrons to move down the road the car on the left moves with you.
- pugworthy 4y agoHah! I’ve seen these for years on some California highways (505 between I80 and I5) and always wondered what they were.
- walrus01 4y agoalso related to I-90 and east of Seattle: https://conservationnw.org/our-work/habitat/i-90/ https://conservationnw.org/our-work/habitat/i-90/
- mostertoaster 4y agoOh my goodness if you have an older car that isnt as quiet as new cars, driving in that right lane along that stretch is the worst, with the constant noise from it. I drive in the left lane until I see someone getting close to me then I get in the right lane till they pass and then switch back to the left lane.