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John Dough posted:I remember there being concrete highways when I was a kid. Then porous asphalts were applied everywhere from the mid-90s onward and the people rejoiced, for their travels were smoother, and they drove unhindered by the rains, and the Lord saw it was good. I just drove I-10 from El Paso to Mobile. Louisiana is so bad. In Alabama, they'd put up a "bump" sign if they were milling before a bridge and there was a 2" elevation change. In Louisiana, there'd be a hole in the pavement the size of a canoe and there wouldn't be any warning. I could hear the suspension of the car bottom out, and it was on the back of a trailer behind the U-haul. Georgia was fine. Mississippi was fine. Louisiana was, by far, the worst road surface I've driven on since Oklahoma.
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May 24, 2013 15:29
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babyeatingpsychopath posted:Louisiana was, by far, the worst road surface I've driven on since Oklahoma. I live in Oklahoma. Take a road--any road--past state lines and there is an immediate and massive upgrade in quality. I40 between OK and Arkansas may change that soon. I know they were working on repaving most of I40 in the state. But until that's finished (it might be already), I'm not aware of a sing road in the state that's better than the same road on the other side of the border.
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May 24, 2013 20:31
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babyeatingpsychopath posted:I just drove I-10 from El Paso to Mobile. Louisiana is so bad. In Alabama, they'd put up a "bump" sign if they were milling before a bridge and there was a 2" elevation change. In Louisiana, there'd be a hole in the pavement the size of a canoe and there wouldn't be any warning. I could hear the suspension of the car bottom out, and it was on the back of a trailer behind the U-haul. Louisiana roads have improved immensely since 2006. I think more than 50% of road construction funds actually go to road construction instead of just 10% and the rest going to the sitting governor's political machine. The fact I-10/12 is actually a road now as opposed to an Indonesia of potholes and half the signs are legible shows real progress. ConfusedUs posted:I live in Oklahoma. Take a road--any road--past state lines and there is an immediate and massive upgrade in quality. At least you guys are fixing IH44 in Tulsa. That road was like driving in 1940...today! Ron Pauls Friend fucked around with this message at 21:44 on May 24, 2013 |
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May 24, 2013 21:39
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Do you guys think with that bridge collapse in WA states/towns might start actually maintaining their infrastructure a little better? Maybe being able to sell tax increases to pay for such things? Or will people just shout "Why don't we just privatize it all so it doesn't cost us anything!!"
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May 24, 2013 22:51
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Baronjutter posted:Do you guys think with that bridge collapse in WA states/towns might start actually maintaining their infrastructure a little better? Maybe being able to sell tax increases to pay for such things? Or will people just shout "Why don't we just privatize it all so it doesn't cost us anything!!" Nah, people will simply believe it can never happen in their own municipality and proceed to do nothing differently.
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May 24, 2013 23:37
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Baronjutter posted:Do you guys think with that bridge collapse in WA states/towns might start actually maintaining their infrastructure a little better? Maybe being able to sell tax increases to pay for such things? Or will people just shout "Why don't we just privatize it all so it doesn't cost us anything!!" I'm going to guess its going to come out the bridge was hit at 60 mph by one of those huge rear end transformers that was 6 in. overheight and unescorted.
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May 25, 2013 00:01
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ConfusedUs posted:I live in Oklahoma. Take a road--any road--past state lines and there is an immediate and massive upgrade in quality. I've been living on the west side of OKC in Yukon since February, commuting to Will Rogers Intl every day. I've become convinced that the roads would actually be better off if they'd just let them deteriorate evenly, instead of this bullshit "fix thirty feet at a time, but not within five miles of the thirty feet we fixed last year." I've honestly been on dirt roads that are smoother-riding than parts of I-40, and a great deal of the surface streets.
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May 25, 2013 00:51
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Baronjutter posted:Do you guys think with that bridge collapse in WA states/towns might start actually maintaining their infrastructure a little better? Maybe being able to sell tax increases to pay for such things? Or will people just shout "Why don't we just privatize it all so it doesn't cost us anything!!" Optimism bias. When the Mianus River Bridge collapsed, Connecticut was the only state that began hiring lots of civil engineers. My boss moved from Michigan to Connecticut because it was the only place in the US he could get a job at the time. Ron Pauls Friend posted:I'm going to guess its going to come out the bridge was hit at 60 mph by one of those huge rear end transformers that was 6 in. overheight and unescorted. True, but it could happen anywhere to any fracture-critical bridge. Part of the cognitive bias is assuming that the cause of an accident was due to an unusual circumstance that wouldn't happen again.
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May 25, 2013 00:54
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Cichlidae posted:Optimism bias. When the Mianus River Bridge collapsed, Connecticut was the only state that began hiring lots of civil engineers. My boss moved from Michigan to Connecticut because it was the only place in the US he could get a job at the time. I was reading a few articles about Mianus after hearing about the collapse in Washington. The Mianus River Bridge was a pin and hanger type I guess, and the failure of one of those pins caused the bridge to collapse. The MRB was eventually replaced with a bridge of a different design, but I take it that there are still bridges in the state with the same pin and hanger design? I'm sure now CDOT makes sure not to pave over storm drains on those bridges like they did on the MRB. http://en.wikipedia.org/wiki/Mianus_River_Bridge
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May 25, 2013 02:00
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porkfriedrice posted:I was reading a few articles about Mianus after hearing about the collapse in Washington. The Mianus River Bridge was a pin and hanger type I guess, and the failure of one of those pins caused the bridge to collapse. The MRB was eventually replaced with a bridge of a different design, but I take it that there are still bridges in the state with the same pin and hanger design? I'm sure now CDOT makes sure not to pave over storm drains on those bridges like they did on the MRB. Pretty sure this bridge currently being replaced is also fracture critical, as well as this one. It was a very common design back in the day, and given the age of most of our bridges, there are certainly a few still around.
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May 25, 2013 03:00
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This may not be answerable, but it's something I've wondered about before. How much of the total strength of a bridge/overpass/whatever goes into supporting itself versus supporting its intended load? Are there any economies of scale to it (ie, increasing strength by 10% increased capacity by 15%)? Although now that I think about it, I may just be asking for (bridge weight)/(capacity)...
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May 25, 2013 03:29
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dupersaurus posted:This may not be answerable, but it's something I've wondered about before. How much of the total strength of a bridge/overpass/whatever goes into supporting itself versus supporting its intended load? Are there any economies of scale to it (ie, increasing strength by 10% increased capacity by 15%)? Although now that I think about it, I may just be asking for (bridge weight)/(capacity)... The terms you're looking for here are live load and dead load. Dead load comprises the weight of the bridge, while live load includes the vehicles traveling across it. There are also wind loads, impact loads, snow/ice loads, and earthquake loads, to name a few, but let's just talk about dead and live for a moment. A bridge's live load capacity vs. dead load isn't something we typically care about. We typically determine the design (live) load, then try to find the cheapest bridge that will carry it while also fitting the site constraints. It's incredibly site-specific, and it'll often be much cheaper to build a concrete bridge over a steel one, even if the concrete is heavier and therefore less 'efficient' on a pound-per-pound basis. For economies of scale, consider rocketry as an analogue. In order to loft a given weight to orbit, you need at least a certain amount of propellant. Now if you want to launch a heavier weight, you'll need more fuel for the payload itself, plus even more fuel to get that extra fuel itself off the ground. Essentially, the heavier your payload, the less efficient the rocket. A bridge is similar: in order to hold up a heavy live load, you need a thick, solid deck, and that's a lot of dead load for the structure to hold up. That means you need heavier beams to hold it, then heavier piers and abutments, and finally bigger and heavier footings. At some point, you could end up with a structure that carries a relatively minuscule live load, but itself is tremendous.
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May 25, 2013 04:02
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Baronjutter posted:Do you guys think with that bridge collapse in WA states/towns might start actually maintaining their infrastructure a little better? Maybe being able to sell tax increases to pay for such things? Or will people just shout "Why don't we just privatize it all so it doesn't cost us anything!!" I expect that they'll shout "Why didn't we catch this? Why couldn't this be prevented?" and someone will point out that maintenance costs money, and the public will tug at their collars uncomfortably and whistle tunelessly while walking out of the room.
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May 25, 2013 05:59
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Figured this'd be the place to get some good I-5 chat. So what I'm curious about is: about how long will it take them to repair the bridge, in all likelihood? Will they be able to set up something temporary, since this is a major trade artery for the U.S and Canada? Are the alternate routes as completely hosed as they appear to be (that poor little town bridge)?
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May 25, 2013 09:23
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Well, will they take the opportunity to replace the bridge properly (that is, demolish the obsolete bridge and build a proper replacement) or will they just fix the busted part?
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May 25, 2013 13:03
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SpaceDrake posted:Figured this'd be the place to get some good I-5 chat.
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May 25, 2013 13:33
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Nice OP. From previous posts this job seems like involving lots of optimization problems, so besides engineering aspects it must be quite mathematical intensive right?
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May 25, 2013 18:33
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I've only gone through the first ten pages, but this thread is a fascinating read. A couple of years ago I read a book called Traffic: Why We Drive the Way We Do, by Tom Vanderbilt, which I enjoyed. Can you recommend any other books that look at the psychology of driving? If you've already answered this somewhere in this monstrosity then I apologize for the repeat question.
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May 25, 2013 18:46
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Slark posted:Nice OP. From previous posts this job seems like involving lots of optimization problems, so besides engineering aspects it must be quite mathematical intensive right? That's what software is for! As an example, there's the Highway Capacity Manual, a big 3-volume set of books that describe empirical formulas to determine delay and queue lengths and ideal cycles and such. At work, we just plug that stuff into our programs and it spits out the answer. The most mathematically intensive work I have to do is redistributing volumes along road networks, but that involves a lot more guesswork and local knowledge than math, and even then, it's just arithmetic. noxiousg posted:I've only gone through the first ten pages, but this thread is a fascinating read. A couple of years ago I read a book called Traffic: Why We Drive the Way We Do, by Tom Vanderbilt, which I enjoyed. Can you recommend any other books that look at the psychology of driving? None that I've read, personally, but I'm sure someone can provide a recommendation or two. Engineers don't tend to be the most empathetic people, so it's often hard to consider things from an average driver's perspective.
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May 25, 2013 19:22
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Traffic is a really good book and if anybody in this thread hasn't read it I highly suggest that they do.
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May 25, 2013 20:05
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How much more capacity would people be able to squeeze out of the current infrastructure if we were suddenly able to all have self driving cars? Some roads feel so packed that even self driving cars wouldn't be able to rid it of traffic jams.
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May 27, 2013 05:22
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mamosodiumku posted:How much more capacity would people be able to squeeze out of the current infrastructure if we were suddenly able to all have self driving cars? Some roads feel so packed that even self driving cars wouldn't be able to rid it of traffic jams. Of course, that's in a perfect world. Once this stuff's out in the real world, there won't be a team of Google/whoever engineers inspecting the vehicle every day. Poorly maintained vehicles, inoperative smart drive systems, lack of maintenance of smart driving features on roads, etc. would probably negate a good chunk of the advantage. Varance fucked around with this message at 06:14 on May 27, 2013 |
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May 27, 2013 06:00
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I think an important factor of self driving cars is that they can theoretically - and it'll be a complete bitch to implement probably - is that they can communicate with each other. So if a car ahead of yours slows for some reason, it can notify cars behind it all at once (rather than a brake light cascade), which I think helps prevent the braking shockwaves that actually cause most traffic jams. I am not optimistic about that happening any time soon, though there are academics and engineers out there trying to figure out how a system like that would work. Of course, self driving cars will probably also create a massive induced demand (which is not the correct term because it's actually cutting costs, not increasing supply, but I'm using it anyway). If you don't have to be paying attention while driving, that would take most of the hassle out of commuting, and tons more people would be willing to sit in traffic if they got to read a book, or mess around on their phone, fool around with their SOs, or just nod off. Which I'm sure is something self-driving-car builders would insist you not do just in case something failed, but I am 110% sure it will happen.
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May 27, 2013 06:49
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Yes, it's like a lava lamp.
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People already do half of those things without self driving cars 
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May 27, 2013 12:02
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Mandalay posted:People already do half of those things without self driving cars Or listen to audiobooks, naturally!
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May 27, 2013 14:29
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PittTheElder posted:I think an important factor of self driving cars is that they can theoretically - and it'll be a complete bitch to implement probably - is that they can communicate with each other. So if a car ahead of yours slows for some reason, it can notify cars behind it all at once (rather than a brake light cascade), which I think helps prevent the braking shockwaves that actually cause most traffic jams. More than once, I have been driving on the highway and looked over to see the driver next to me holding a book with both hands against the steering wheel.
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May 27, 2013 16:55
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GWBBQ posted:Last I heard, they're looking for a Bailey Bridge that will fit for now but will be replacing the whole thing. Just an update: Seattle Times says today that a temporary I-5 bridge will be in place by mid-June, with a permanent fix by the end of September. They will not be replacing the entire span, just the part that fell.
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May 27, 2013 17:07
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NightGyr posted:More than once, I have been driving on the highway and looked over to see the driver next to me holding a book with both hands against the steering wheel. Sweet almighty Atheismo, that is absolutely hosed up, and something I'm kind of glad I've never seen first hand (which doesn't mean anything I know). I thought the only people stupid to pull that poo poo were mayors of Toronto who were entitled to a chauffeur but declined to use one.
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May 27, 2013 17:47
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The few times I have to drive on a proper highway I see so many distracted drivers. When you're driving in the city you have to be super aware. There's a bike lane to your right, there's constant j-walkers, there's a traffic light or stop sign every block and tons of pedestrians. You really have to be fully paying attention, and there's constantly things that need your attention so it's almost impossible to fully zone out. But on the highway when you're just driving in a straight line for like 20km and all you need to do is more or less stay within your lane so many drivers seem to lose focus. And if they have to do some horrific hour long highway commute every day they're going to get so used to that route and start feeling like they can text, or watch a movie, or read a loving book. Combine that with idiots never driving the proper 3-second distance between each other and you get all these rad 10 car pile-ups as every distracted idiot slams into the back of the previous distracted idiot. Baronjutter fucked around with this message at 18:47 on May 27, 2013 |
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May 27, 2013 18:45
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NightGyr posted:More than once, I have been driving on the highway and looked over to see the driver next to me holding a book with both hands against the steering wheel. PittTheElder posted:Sweet almighty Atheismo, that is absolutely hosed up, and something I'm kind of glad I've never seen first hand (which doesn't mean anything I know). I thought the only people stupid to pull that poo poo were mayors of Toronto who were entitled to a chauffeur but declined to use one. I've seen that many times. Sometimes huge novels mostly above the steering wheel. It made me wonder how much of that they read while driving. Then I've seen some people holding an entire newspaper up and driving. Also seen drivers holding those huge fold out maps that block every bit of vision; unless they strategically put a hole in the middle of the map to see through. I want to say I've seen an instrument being played before as well, but I'm not sure if I brainwashed myself into thinking that from all the pictures I've seen on the internet of people doing it. Pretty much all of this was on interstates too, where people are travelling anywhere from 60 ~ 80 MPH.
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May 27, 2013 18:53
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mamosodiumku posted:How much more capacity would people be able to squeeze out of the current infrastructure if we were suddenly able to all have self driving cars? Some roads feel so packed that even self driving cars wouldn't be able to rid it of traffic jams. If they're narrower than current cars, like some single-person pod cars I've seen, we could probably increase capacity fourfold. Just hope there are no mechanical failures, because the potential for chain-reaction collisions is much higher. NightGyr posted:More than once, I have been driving on the highway and looked over to see the driver next to me holding a book with both hands against the steering wheel. Last time I saw that, it was a fellow state employee, in a state car, on a freeway. ----- Here's some food for thought: what if gas prices suddenly rose to $100/gallon? Granted, it'll never happen (at least not all at once), but imagine prices hit that peak tomorrow morning. How would your life change? I know that, with my short commute, I wouldn't need to change my driving habits. I live very close to work, so I'd be fine. However, prices for almost every consumer good would rise precipitously. I'd be encouraged to telecommute, which would be pretty sweet. My job would get a lot easier, too, since traffic volumes would fall by at least 70%. I might be laid off, though, as the state is immediately plunged into a budget crisis. Maybe I could be an electric bus driver...
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May 27, 2013 19:09
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My personal life wouldn't change much at all since I drive maybe once a week. Transport to my island would get even more expensive and we'd see even higher prices than the rest of north america. I guess I'd mostly just sit around bitter saying "I told you so!!" about nuclear power and more local farming and hope that comforts me when the mad-max style gangs attack. Nah there won't be mad-max style gangs, just tons of armoured SUV's driven by private security escorting the elite around cities while the population throw rocks and piss-bottles at them. Motolov cocktails simply being too expensive 
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May 27, 2013 19:19
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Varance posted:SPUI! Just like Hooters, Clearwater has the first one ever built.
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May 27, 2013 19:26
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Cichlidae posted:If they're narrower than current cars, like some single-person pod cars I've seen, we could probably increase capacity fourfold. Just hope there are no mechanical failures, because the potential for chain-reaction collisions is much higher. If fuel went to $100 a gallon, you wouldn't need to telecommute, because you'd essentially need to be in your backyard, growing your own food all day. Also, your next months electric bill would likely be about the same as your last months bill, assuming the only thing you ran was your refrigerator.
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May 27, 2013 19:43
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MrYenko posted:If fuel went to $100 a gallon, you wouldn't need to telecommute, because you'd essentially need to be in your backyard, growing your own food all day. Also, your next months electric bill would likely be about the same as your last months bill, assuming the only thing you ran was your refrigerator. This only works if you live in a small house on a big lot, preferably on an actual farm, and not in an apartment complex near the freeway. Which is to say that a lot of us would perish very quickly. Survivalism stinks.
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May 27, 2013 19:46
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Hedera Helix posted:This only works if you live in a small house on a big lot, preferably on an actual farm, and not in an apartment complex near the freeway. Which is to say that a lot of us would perish very quickly. I was being optimistic.
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May 27, 2013 19:47
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MrYenko posted:If fuel went to $100 a gallon, you wouldn't need to telecommute, because you'd essentially need to be in your backyard, growing your own food all day. Also, your next months electric bill would likely be about the same as your last months bill, assuming the only thing you ran was your refrigerator. Yeah, $100/gallon is "existential threat to civilization" price levels, since that would affect diesel which affects freight and mass transit. At that price I would liquidate all of my assets and head to the wilderness for a chance for survival. A better question might be $20/g as that's not quite on the "bread costs $5000/loaf" level.
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May 28, 2013 00:13
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As a non-CT resident who drives there pretty regularly (fiancee's from West Haven), what the heck is it with the stretch of 95 leading up to Exit 14-15 from either direction? It's ALWAYS backed up, and I have no idea why - the minor amount of construction going on there isn't nearly enough to produce the level of traffic that I see on a regular basis.
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May 28, 2013 00:55
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Norwalk always backs up because the interchange for US 7 is poo poo and there's about three exits in the span of two miles.
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May 28, 2013 01:46
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Volmarias posted:Yeah, $100/gallon is "existential threat to civilization" price levels, since that would affect diesel which affects freight and mass transit. At that price I would liquidate all of my assets and head to the wilderness for a chance for survival. The agency I work for is switching to CNG. Diesel is a terrible fuel for transit now that SCR systems are required and increase breakdown rates fourfold. Edit: Let me expand on that one a bit. In order to meet EPA emmissions standards, most of the American diesel engine manufacturers have incorporated a process called Selective Catalytic Reduction (SCR) into the design of diesel engines. Diesel Exhaust Fluid (code for laboratory manufactured urea - ya know, the main ingredient in human urine) is vaporized and injected into the exhaust as a catalyst, allowing the vehicle's diesel particulate filter to trap certain pollutants along with engine soot. Sustained high exhaust temperatures (IE from highway driving) then burn off the trapped soot particulate, cleaning out the filter in a more environmentally friendly manner. Problems: 1) This system is designed for freight trucks, which spend a lot of time on expressways. They do not regenerate properly in stop-go traffic, causing engines to go into reduced power mode (25MPH max) whenever the filter clogs in order to avoid a critical engine failure. Once they go into low power, you have to pull the unit from service and "regenerate" the filter by using a maintenance console to redline the engine for an hour - consuming about $20-30 worth of diesel and potentially blowing apart a $500 filter in the process. Yeah, it's not the best solution for transit. DEF buses are incredibly unreliable if they're not on express routes. Transit vehicles that NEVER go on highways need to be fully regenerated at least once a week... and even then, you can expect them to be down at the local Cummins/Detroit Diesel service outlet for warranty work every few months. Garbage trucks also have the same problem. 2) DEF costs money. About $7/gallon at bulk rates, which only covers about 400 miles of transit usage. That's about a day of use for most agencies, assuming they use the vehicle from beginning to end of service. $7 a day doesn't sound like a lot, but when you multiply that by hundreds of vehicles, it gets expensive fast. Millions of dollars a year in DEF for larger systems, on top of current high diesel prices. Expect a mass exodus of transit agencies away from Diesel vehicles once they start figuring this stuff out. CNG is currently the most viable alternative - all you need is a gas feed and a compression setup to get going, pays for itself in a year in terms of diesel/DEF savings (in our case, FTA paid for everything under an alternative fuel grant), plus the tech is robust from being used for decades in places like California. Mass-replace your RTAP (paratransit) fleet first to realize massive fuel savings for a fraction of the cost of bus replacement, then use the money saved from the diesel budget to accelerate vehicle replacement with new CNG units. Electric will probably become dominant a decade from now, once the tech matures and comes down in price - which will probably be around the same time that CNG starts losing its price advantage due to wide adoption and increased fracking regulations. Varance fucked around with this message at 05:27 on May 28, 2013 |
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May 28, 2013 02:18
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