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Cichlidae posted:Here's another worker setting up the signal cabinet. He's sealing the cracks, which is awesome, because you can't imagine the number of wasps and snakes that love to live in the warm, dry clime of a signal controller cabinet. How's the ventilation in there? It looks like there's an air filter of some kind on the door. Is there a fan that keeps the box ventilated so all the electronics don't overheat? I see your signals are dangled from wires. I hate those almost as much as toll roads (wires everywhere are ugly!) but one angry rant per day is probably enough  .
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Aug 21, 2009 18:12
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Choadmaster posted:Charging a toll for driving on an interstate freeway seems to me like a terrible sin. Don't those things get federal money? As a taxpayer I should be able to go anywhere on the interstate freeway network without having to stop the car and dig for change every eight miles. Usually if there is state or federal money involved the story usually goes like this: "Hey public, let's build a toll road to get around all that nasty traffic, and we'll take the toll booths away once it pays for itself - promise promise" 20 years later... "Yeah, we'd love to take away the toll booths but then again why would we want to? Tell you what, let's see what the sub-committee of the profitable status quo says about it."
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Aug 21, 2009 18:22
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Choadmaster posted:This reminds me: What's with the absurd number of toll roads in the northeast? But in general, the road tolls aren't that bad in the Northeast. It's a couple of bucks and usually there are other options if you care. The main pain nowadays is the bridge tolls around NYC. To get from CT to Long Island, it's $5.50 each way. To cross the George Washington Bridge, it's $8. quote:Charging a toll for driving on an interstate freeway seems to me like a terrible sin.
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Aug 21, 2009 19:18
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Last September, I drove from Oklahoma to South Carolina, and had the bright idea to stop by the Ikea store in Atlanta to pick up a folding chair. (Yep, all this for a drat chair.) My route was: drive east on I-20 into Atlanta, head north of I-75, and the store will be about a couple blocks southwest of this: dennyk posted:Tom Moreland Interchange When I finally got my chair, I set my GPS to head back to the intersection of I-75 and I-20, A.K.A.: quote:Malfunction Junction Everything. I forgot to change my clock ahead (I thought it was 3:45pm, but it was actually 4:45), and Georgia was in the middle of a gas shortage, which meant everybody was out looking for more. I counted stretches where we had 16 lanes -- bridges, ramps, sideroads -- all of them were packed, and for 2-3 minutes at a time nobody was going anywhere. We would inch forward, stop, inch forward, stop. It took me 75 minutes to travel from one interchange to the other. There wasn't any construction; it was simply that busy. (Oh, and I was one of the lucky ones to find gas that day: about 30 miles east in Conyers for the bargain price of $4.39/gal!) Cichlidae, I applaud traffic engineers like you who try your best to design something slick and massively efficient, but you're right.. We will always find some way to clog it up. It's amazing. quazi fucked around with this message at 21:20 on Aug 21, 2009 |
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Aug 21, 2009 20:59
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Choadmaster posted:This reminds me: What's with the absurd number of toll roads in the northeast? I'd been all over western states (California/Oregon/Washington/Nevada/Utah) and never had I used a toll road until taking a road trip to the northeast, where they seem to be loving everywhere and you literally cannot avoid them. Hey, hey hey! Not ALL of us do that. New York and New Jersey, sure. Massachusetts, New Hampshire and Maine, a little bit. Tolls are outlawed in Connecticut since 1988, and Rhode Island only has one, for the Newport Bridge. New Jersey, Delaware, and Texas really love tolls. Those jerks! They even have anti-shunpike measures. quote:The few (three or four) tolls I've noticed in California (bridges excepted) seem to be for privately run highways that go the same places the interstates do, just with way less traffic (ie. CA-91) or areas where they've added a couple extra lanes to the highway and charge a toll for those, again for people who want to avoid the regular traffic. Until recently, any toll road was ineligible for federal funding. The rules have changed, though, to be somewhat more lenient. Just remember, driving isn't a right. The government isn't required to provide you with roads. Even federal roads are maintained by the state; the FHWA doesn't have some giant maintenance division that fixes them up. In states where there are no tolls, the majority of our funds come from gas taxes, and it's SUPER hard to raise gas taxes, politically. quote:I can somewhat understand Oklahoma doing it (I think I took I-44 across half the state and the entire stretch was tolled) because their population density is so low that maintaining a long freeway through the middle of nowhere must be difficult. But population density in the northeast is even higher than California's! Hey, I'm not fond of tolls, either. Their purpose is to get maintenance/construction money from the people who actually use the road. Some people get upset when they're charged money for a road they never take. Gas tax is a different approach, but people with more efficient cars end up paying less. That is rather fair, though, since larger vehicles do a MASSIVE amount of damage compared to their lighter brethren. There are other ways to get money. Rhode Island put a tax on rental cars to pay for their new multimodal station at T.F. Green. Back in the old days, we raised money with lotteries. Problem is, in small states like we have in the northeast, a large percentage of traffic is through traffic, and won't stick around long enough to buy gas, rent a car, or buy a lottery ticket. Hence, tolls. Put them at the border, and at least we can gently caress over those New Yorkers as much as they gently caress us with their tolls. Edit: smackfu posted:I'm sure Cichlidae will talk about the Connecticut toll story, which is interesting. Toll roads in CT have been built for the last 300 years. In the 1930s, when US 1 was getting super congested, the decision was made to build a new road a few miles inland to handle its traffic. There were a few toll booths installed on this road, the Merritt Parkway, to finance its eventual extension eastward. Lo and behold, it worked so well, they completed the route (except for the Berlin Turnpike) a few years later. The toll booths stayed, because, hey, money! Soon, both the Parkway and US 1 were filled to the brim again (remember what I keep saying?), so the state decided to build a new freeway, the Connecticut Turnpike. This road had tolls as well, keeping the DOT coffers relatively full. All of these tollbooths were the barrier type, which meant that, every 10 or so miles, all traffic would stop, pay the toll, and drive through. Can you see what the problem is? In 1983, a trucker fell asleep at the wheel and plowed into the toll queue, killing several people. Oops! Turns out it wasn't a one-off thing, either, because it happened again. The DOT wisely chose to close down the tollbooths. The rest of the state's tollbooths were closed when the feds oh-so-subtly hinted that CT wouldn't get any federal funding if we were collecting tolls. Tolls were outlawed here in 1988. We raised the gas tax to compensate, but it was only a temporary increase, and when it went back down in the 1990s, the DOT lost a great deal of its income. Ah well. Cichlidae fucked around with this message at 22:13 on Aug 21, 2009 |
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Aug 21, 2009 21:54
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Choadmaster posted:How's the ventilation in there? It looks like there's an air filter of some kind on the door. Is there a fan that keeps the box ventilated so all the electronics don't overheat? I actually don't think there are any fans in there. The filter has some louvered vents behind it, so air can get in and out, but that's about it. With all those electronics, it gets very hot in Summer, but they're field-hardened electronics, and the metal case is pretty heat-conductive. Regarding span wires, hope you don't ever meet THIS GUY. If you don't want to read the whole rant, he believes that mast arms (the alternative to span poles) are ugly and racist. That's right, the signal heads represent minorities hanging by their necks. I was reading a corridor study report today and got down to the public comments section. What did I see? 9 pages of rambling wall-of-text word soup from Mr. Crazy himself. This guy gets around. If I told you his name, you could find several tasteless things he's posted on public sites, some involving his love of humping a certain brand of motorcycle.
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Aug 21, 2009 22:01
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quazi posted:Last September, I drove from Oklahoma to South Carolina, and had the bright idea to stop by the Ikea store in Atlanta to pick up a folding chair. (Yep, all this for a drat chair.) Hmm, it sure is hard to find gas today. What should we do? Oh, I know! Let's drive around in gridlock traffic for 3 hours looking for more gas! I'm so smart! Weren't those shortages caused by people spreading rumors, which actually came to fruition when there were runs on the pumps? quote:Cichlidae, I applaud traffic engineers like you who try your best to design something slick and massively efficient, but you're right.. We will always find some way to clog it up. It's amazing. Yeah, all we can do is build roads that will still be passable in 20 years. The only way to make a road that can't be clogged is to put bottlenecks on all the entrances, like ramp metering. You're just pushing the congestion onto local roads, in that case.
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Aug 21, 2009 22:23
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Cichlidae posted:Put them at the border, and at least we can gently caress over those New Yorkers as much as they gently caress us with their tolls. Why not put a barrier toll on the wee bit of I-684 that passes through Greenwich, where there are no on or off ramps for CT drivers.  Cash windfall for CT
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Aug 21, 2009 23:34
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Lobstaman posted:Why not put a barrier toll on the wee bit of I-684 that passes through Greenwich, where there are no on or off ramps for CT drivers.
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Aug 21, 2009 23:43
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Lobstaman posted:Why not put a barrier toll on the wee bit of I-684 that passes through Greenwich, where there are no on or off ramps for CT drivers. Haha, that reminds me of a tiny little town here in Oregon called Coburg. (edit: Excuse me while I get all 'Cops on the Beat' here) Now Coburg is just to the NW of Eugene, and the interstate passes by it just a couple miles away. However, there is no direct access to the interstate by the city, you have to drive around for a good 10 minutes to get onto the freeway. But the good old boys in the Coburg PD were frustrated at hearing all that traffic go by but not having anything to do with their brand new Chargers, so they decided to just drive out of their jurisdiction and then back onto the part of the freeway near their town. Low and behold, it was a ticket-topia. Tons of cops with nothing to do but bring back loads of money for their town. Motorcycle patrols brought home up to half the municipal budget (yes, 50 percent, normally it's around 4 percent here in Oregon). The little town of 1,000 managed to have the highest per capita police presence in the state, with eight officers providing round the clock coverage and two traffic cops tasked solely with patrolling the freeway. Now eventually Eugene and the surrounding community got a bit miffed about this whole highway robbery situation that was killing tourism a wee bit, so they complained and the state Congress put together a "Coburg Bill" that made it so that tickets issued outside city limits would be paid in county courts (thus drying up income). So the boys in Coburg sat down and thought about it for a little while, and they came up with the bright idea of simply annexing a strip of I-5 that they then could patrol. Now, this story doesn't really end. They've cut back a little bit, mostly because they spent too much money on shiny cars and ran out of funding during the recession. They've had to fire three officers as well as Mike Hudson, the guy who was spearheading this whole operation. http://seattletimes.nwsource.com/html/localnews/2004103025_weborspeedtrap01m.html http://www.thefreelibrary.com/Coburg+patrolman+nabs+drivers+speeding+at+freeway+interchange.-a083720230 http://news.google.com/newspapers?nid=1310&dat=20050518&id=c1oUAAAAIBAJ&sjid=gPADAAAAIBAJ&pg=3333,4106977 Here's the interchange that they were 'patrolling'. Apparently they were worried about traffic past their city hall, but I find that hard to believe seeing as it's 10 minutes off the freeway: http://maps.google.com/maps?hl=en&c...=title&resnum=1 Kaal fucked around with this message at 01:58 on Aug 22, 2009 |
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Aug 22, 2009 01:52
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Lobstaman posted:Why not put a barrier toll on the wee bit of I-684 that passes through Greenwich, where there are no on or off ramps for CT drivers. Two barrier tolls, since it crosses the border twice  Socket Ryanist posted:NYDOT maintains that stretch It's only a mile and a half long. We could maintain it for pretty cheap, and a $10 toll would go a long way toward paying for that. New York may maintain it, but it's still our land, much like northern Ohio used to be!
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Aug 22, 2009 01:54
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Kaal posted:Haha, that reminds me of a tiny little town here in Oregon called Coburg. (edit: Excuse me while I get all 'Cops on the Beat' here) Now Coburg is just to the NW of Eugene, and the interstate passes by it just a couple miles away. However, there is no direct access to the interstate by the city, you have to drive around for a good 10 minutes to get onto the freeway. These guys know how it's done. I'm glad we don't have any isolated, small towns up here, because that would be tough to deal with. That, and I'd have to take off my dress clothes when I went to meetings with them. Lame! So how were they issuing tickets outside their city limits, anyway? I thought police couldn't work outside their jurisdiction. I only see the staties issuing tickets on interstates around here. I guess it makes sense, though. If you're an officer and you see someone breaking the law, you stop them, no matter where you are.
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Aug 22, 2009 02:05
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Cichlidae posted:These guys know how it's done. I'm glad we don't have any isolated, small towns up here, because that would be tough to deal with. That, and I'd have to take off my dress clothes when I went to meetings with them. Lame! If Oregon is like California then any peace officer can issue citations/make arrests anywhere in the state.
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Aug 22, 2009 08:55
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dexter posted:If Oregon is like California then any peace officer can issue citations/make arrests anywhere in the state. To the best of my knowledge this is not true for California. The only two groups with that ability are the Highway Patrol and the University of California police departments. Yes, the latter seems sort of odd but I think it's so the UC cops can aid local departments in dealing with student-related issues regardless of jurisdiction. I've seen my local UC police giving speeding tickets on the highway adjacent to campus - but I was told by a friend who worked for the UC police that if they stray too far from campus it starts to piss off the CHP (this is the same reason local cops here tend not to police the highways even inside their jurisdiction). Edit for more info. Choadmaster fucked around with this message at 10:13 on Aug 22, 2009 |
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Aug 22, 2009 10:10
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Just a couple questions for the OP-- how have things like environmentalism, environmental impact surveys, and other "green" policies of the sort affect your design decision? How often do they affect us (contributing to our misery during rush-hour) unbeknownst? For example, I can think of some cases where major corridors needed widening, but it never happens because there's a stupid pond with a fish, or a bird in a tree somewhere that is supposedly rare. Millions of people are therefore left frustrated because they have to sit bumper to bumper each day as a result. I could imagine this happening everywhere, but I'd like to get your take on it. lvx occvlta fucked around with this message at 12:16 on Aug 22, 2009 |
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Aug 22, 2009 12:14
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Cichlidae posted:Hmm, it sure is hard to find gas today. What should we do? Oh, I know! Let's drive around in gridlock traffic for 3 hours looking for more gas! I'm so smart! Weren't those shortages caused by people spreading rumors, which actually came to fruition when there were runs on the pumps? There really were issues with supply for a while, but the problem was greatly exacerbated by people hoarding fuel and everyone rushing to top off their tanks every time a station got a delivery in.
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Aug 22, 2009 15:54
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lvx occvlta posted:Just a couple questions for the OP-- how have things like environmentalism, environmental impact surveys, and other "green" policies of the sort affect your design decision? How often do they affect us (contributing to our misery during rush-hour) unbeknownst? All the time, on every project. We need to do some environmental work on every project. For the Traffic department, it's usually very minor, since installing a signal or turning a railroad into a bike path doesn't involve a lot of impacts. All the same, we need to look out for air quality when we install a signal. Generally, if it's warranted, a signal will reduce delay and therefore save some gas, but this isn't always the case. If the project is minor enough, we can file for an exclusion, be it categorical or programmatic. Categorical exclusions are for very specific cases, such as transferring right-of-way from a railroad. Programmatic exclusions, we have to apply for, and basically they mean "what we're doing is so minor, we shouldn't have to calculate the real impacts." If the project involves a FOSI (Finding of Significant Impact) and it uses federal money, than NEPA dictates that we need an EIS (Environmental Impact Statement). Developing an EIS is a years-long process with multiple drafts. The EIS establishes the need for the project, looks at several alternatives, including a no-build, and compares them all based on environmental, community impacts, constructability, cost, and environmental justice. A preferred alternative is chosen, and passed forward. At this point, ideally, a project is ready for design. In reality, you'd better have a good lawyer, because there will be lawsuits flying around like mosquitos in a swamp. Maybe the Sierra Club thinks you could have spent a few million more dollars to build a wider culvert over that stream, the Army Corps of Engineers thinks that your road will cause flooding, some old lady doesn't want her house to be taken, NAACP thinks your project has excessive impacts on a minority community... but I'm getting off topic! Up in New England, there are wetlands all over. It's not just a coastal thing. If I build a storm drain and have it empty into a field, that field will become a protected wetlands area, despite the origin of the water. If I'm going to widen a road and need to take some of that wetlands, I need to do environmental mitigation elsewhere. For one of my projects, that meant chopping down some Phrag in another town. One of my coworker's projects, the extension of US 7 in Brookfield, had some even bigger problems. After fighting lawsuits for literally 30 years, construction finally began, only to be temporarily halted because a species of endangered salamander was found that had moved in since the original survey. I think they ended up building a bridge over that pond; you can imagine, it gets expensive. One of my projects was in a box turtle habitat. We have to schedule construction around the mating season, and our work crews have to comb the river in that area for any box turtles and bodily move them away from the site. I really don't mind; endangered species are something worth worrying about. But hey, my fiancée has a Masters in Environmental Science and Management, so maybe I'm a little biased. Choadmaster posted:To the best of my knowledge this is not true for California. The only two groups with that ability are the Highway Patrol and the University of California police departments. Yes, the latter seems sort of odd but I think it's so the UC cops can aid local departments in dealing with student-related issues regardless of jurisdiction. I've seen my local UC police giving speeding tickets on the highway adjacent to campus - but I was told by a friend who worked for the UC police that if they stray too far from campus it starts to piss off the CHP (this is the same reason local cops here tend not to police the highways even inside their jurisdiction). That makes sense. All the interstates in RI were patrolled by state troopers only. All the local cops stuck to local roads. My mom got in a car accident once, and the police drove her to the town line, where the next cop picked her up and drove her home.
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Aug 22, 2009 16:20
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Cichlidae posted:So how were they issuing tickets outside their city limits, anyway? I thought police couldn't work outside their jurisdiction. "Well you see Judge Friendly McLocal, these arrests are within our jurisdiction, because we patrol on both sides of that freeway. And while we might have to travel outside the borders of our incorporated town to do so because there is absolutely nothing to police on the east side of that interstate, we just love freedom so much that we do it anyways." "Well officer, that all sounds quite legal to me. I'll allow it. We're all just so proud of you folks here in Coburg. Keep up the good work of funding our town and administering peace and justice to those Godless heathens down in Eugene." dexter posted:If Oregon is like California then any peace officer can issue citations/make arrests anywhere in the state. Fortunately this is not the case. Kaal fucked around with this message at 22:19 on Aug 22, 2009 |
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Aug 22, 2009 19:15
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First off let me say that this is a great thread, Cichlidae. I've been reading it the whole way through and I wanted to point out a type of interchange that I don't think I saw mentioned before: The diverging diamond interchange (DDI). Here's the wikipedia link to it: http://en.wikipedia.org/wiki/Diverging_diamond_interchange. The powers that be at MODOT have decided that St. Louis needs one of these, so we're getting one at I-270 and Dorsett. MODOT's link to it actually has some pretty decent animations of traffic going through it. http://www.modot.org/StLouis/major_projects/I-270andDorsettInterchangeProject.htm If you look, you'd see that traffic going straight on the non-interstate road switches to the left side of the road and then back to the right side. Now, my first thought is that the number of head-on collisions will increase greatly as Granny McGee cannot comprehend driving on the left side of the road. Just wondering what you thought about this. Thanks again for the great thread.
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Aug 23, 2009 00:06
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coop999 posted:First off let me say that this is a great thread, Cichlidae. I've been reading it the whole way through and I wanted to point out a type of interchange that I don't think I saw mentioned before: The diverging diamond interchange (DDI). Here's the wikipedia link to it: http://en.wikipedia.org/wiki/Diverging_diamond_interchange. I mentioned it back on the first page, but that's a long way back, so I don't mind a recap quote:The powers that be at MODOT have decided that St. Louis needs one of these, so we're getting one at I-270 and Dorsett. MODOT's link to it actually has some pretty decent animations of traffic going through it. http://www.modot.org/StLouis/major_projects/I-270andDorsettInterchangeProject.htm I was talking with my boss just yesterday about DDIs, and explained the concept again (since he'd forgotten the first time). He's pretty enthusiastic about the idea, and we discussed a couple places we might put them in. Now a DDI is great, but it can also introduce weaving! That's why, in France, they have a special channelized version that takes care of the weaving without introducing more signals or phases. 
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Aug 23, 2009 00:33
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Choadmaster posted:To the best of my knowledge this is not true for California. The only two groups with that ability are the Highway Patrol and the University of California police departments. Yes, the latter seems sort of odd but I think it's so the UC cops can aid local departments in dealing with student-related issues regardless of jurisdiction. I've seen my local UC police giving speeding tickets on the highway adjacent to campus - but I was told by a friend who worked for the UC police that if they stray too far from campus it starts to piss off the CHP (this is the same reason local cops here tend not to police the highways even inside their jurisdiction). California police officers have primary jurisdictions which are normally limited to their city or county. CHP, UC and CSU departments have primary jurisdiction anywhere in the state according to 830.2. 830.1 covers other peace officers: quote:(a) Any sheriff, ... any police officer, employed in that capacity and appointed by the chief of police or chief... is a peace officer. The authority of these peace officers extends to any place in the state, as follows: Local departments here constantly issue citations for violations well outside their primary jurisdiction. They won't sit on the shoulders and such to run traffic but will ticket you for anything they observe while traveling. Maybe it's a San Diego thing that other departments are more strict outside of their city, I don't know. Sorry about the derail.
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Aug 23, 2009 00:38
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Cichlidae posted:I joke sometimes about people calling us and wanting signals installed at their driveways. It's not always a joke... people actually do that. Imagine the sweet delicious irony when I woke up one morning to find a work crew had cut some loops at the end of my driveway! Yes, that's right, they're out there right now installing a signal. Check it out. One of my clients is a signal company. I was kinda floored when I saw a signal sitting in their shop, they are loving huge! I also find it hilarious that all signal controllers(The boxes, whatever those are called, at least)are basically exactly the same in terms of hardware, despite brand differences. The guys that program them are annoying, as they think that since they deal with 30 year old computer hardware they know my job. Congrats on knowing how to blow an EEPROM, gramps.  And in regards to the Oklahoma Road hate: A lot of the interchanges suck, but our road quality isn't any worse than other places I've lived(With a few exceptions: The Crosstown in OKC, I-44 and I-244 in Tulsa are all pretty rough). Missouri was probably worse, on average. Non-major routes in western New York are horrible. Speaking of, I have a question: On two separate turnpikes in OK, there are long, curving bridges made on concrete. Said concrete is very bumpy, but in a predictable way. It's like steady waves on a boat and are fairly far apart(You feel the car going up and down, rather than just bumps like a corded road). What causes this? Poor design? Poor construction? Some intentional crazy traffic thing to make you slow down?
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Aug 23, 2009 02:55
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Citizen Z posted:One of my clients is a signal company. I was kinda floored when I saw a signal sitting in their shop, they are loving huge! Yep, they're all standard NEMA electronics with standard NEMA plugs. About the only thing that varies between controllers is the number of buttons you need to press to break them. quote:And in regards to the Oklahoma Road hate: A lot of the interchanges suck, but our road quality isn't any worse than other places I've lived(With a few exceptions: The Crosstown in OKC, I-44 and I-244 in Tulsa are all pretty rough). Missouri was probably worse, on average. Non-major routes in western New York are horrible. It could be one of many things. We wouldn't introduce bumps in a freeway to slow you down, because that'd be rather dangerous. I'd say the most likely reason is that they were made with straight, flat precast concrete beams. When you have a curved bridge, you can either get custom curved beams, which are super expensive, or use straight/flat ones and hope they're close enough that people won't notice. I guess I should explain a little bit how precast beams are made. They have very strong cables running through them which are either put in tension as the concrete cures or at the job site. The cables squeeze the concrete, sort of like wrapping your hand with rubber bands. Your hand is in compression, the bands are in tension. Concrete is much much stronger in compression than tension, so adding a little stress like this actually makes it stronger by reducing the amount of tension that can be introduced. I can explain it in more detail if you want, but it's not really essential to the conversation. These precast beams have to be small enough to transport (100 feet or so). This lets us get away with using flat/straight beams on curved bridges. Observe:  So, assuming they used flat beams on those bridges you mentioned, you could be feeling the not-quite-smooth boundary between different beams. If they seem to coincide with the occasional expansion joint, that's more evidence. Another idea is that the camber isn't proper. Concrete bends just a little bit, but it's enough to feel and see. We put in a camber, or upward curvature of the beams, so that when concrete is placed over the beams, and cars drive over it, the extra weight makes it flat. It's not always a perfect estimate. Add too thick of a bed of concrete, and that camber's not enough. You get sags in the beams. This isn't outright dangerous, but it can be uncomfortable, as it produces bumps much like you described. Option number three: concrete 'creeps' as it ages. Each time concrete is poured, we have to take samples to be tested later for creep. Some batches creep more than others, and it's not easy to predict. Creep generally won't get you THAT much deflection, though.
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Aug 23, 2009 04:50
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Wow, that's fascinating. For starters, what's concrete 'creep'? Is that like the slow movement of glass? And could you talk a little bit more about the tension cabling? I didn't quite understand how you could introduce the compression.
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Aug 23, 2009 06:57
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Kaal posted:Wow, that's fascinating. For starters, what's concrete 'creep'? Is that like the slow movement of glass? And could you talk a little bit more about the tension cabling? I didn't quite understand how you could introduce the compression. First off, glass doesn't flow. That's an urban legend resulting from some misconceptions about how glass was made in the middle ages. Concrete creep is a pretty strange phenomenon, because it's made up of solid components, but they still move. It's a response to long-term stress (keeping your car parked in one spot for many years can make a concrete slab creep) that is caused by "equalizing stresses." I don't know what that means, exactly, but it's enough to know that concrete will slowly deform over time. As to tension cabling, check this out!  Edit: To clarify in that third frame, a block of steel is just as strong in compression as in tension, but rebar will buckle under a relatively small load when compressed due to its shape. Cichlidae fucked around with this message at 16:42 on Aug 23, 2009 |
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Aug 23, 2009 16:32
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You can see (miserable) examples of those gaps between concrete slabs at the south exit of the DFW airport (yay more lovely Dallas roads!) on the ramp to 183 East. I cringe every time I drive over this, the gaps are 4 or 5 inches wide now. I have a question regarding tollbooths, I was driving around at home in Chicago this past weekend and noticed something weird that seems counterintuitive: at exits where the traffic MUST pass through a tollbooth, the "I-Pass Only" lanes are on the RIGHT side of the toll plaza, and after cars pass through they must claw back through to the LEFT side of the road to merge with the new traffic. What's up with that?
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Aug 24, 2009 19:58
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Cichlidae posted:Massachusetts, New Hampshire and Maine, a little bit. In fact, the only places I can think of in Massachusetts with tolls are along the New Hampshire border (which I think is split between the two states), on the entrances to the Mass Pike, and on the Tobin Bridge into Boston (but not on the way out).
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Aug 24, 2009 22:00
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Stew Man Chew posted:You can see (miserable) examples of those gaps between concrete slabs at the south exit of the DFW airport (yay more lovely Dallas roads!) on the ramp to 183 East. I cringe every time I drive over this, the gaps are 4 or 5 inches wide now. Concrete's expensive to repair, too. It's not like asphalt where you can just mill the top few inches and add a new layer, since there's rebar inside it. You've got to replace the whole slab, which means putting the whole road out of commission. Of course, there are some who have tried to repair concrete on the cheap. Let me show you how that went.  quote:I have a question regarding tollbooths, I was driving around at home in Chicago this past weekend and noticed something weird that seems counterintuitive: at exits where the traffic MUST pass through a tollbooth, the "I-Pass Only" lanes are on the RIGHT side of the toll plaza, and after cars pass through they must claw back through to the LEFT side of the road to merge with the new traffic. What's up with that? Someone else mentioned that, I think in Massachusetts. Since we don't have tolls here, I don't know too much about them. There's a good chance it's a legacy thing. Either the rightmost booths were added later, and there was no room on the left, or the booths used to be another payment method and it was cheaper/easier to convert them than it would have been to convert the left ones. It certainly would make more sense, traffic-wise, to keep high-speed traffic on the left. Unfortunately, traffic engineers don't rule the world!
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Aug 24, 2009 22:13
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I will say this for New England road design. I was in Maine this weekend, and we took I-95 both ways, and the stretch of it which is also the Maine Turnpike seemed very well-designed and maintained. Additionally, the border tolls had EZ-pass booths on both sides rather than just one.
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Aug 24, 2009 22:38
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So have you traffic engineers been paying any attention to the Alaskan Way viaduct fiasco over here in Seattle? We're having an election right now and the Mayoral candidate who may very well win has "no tunnel!!" as basically his entire platform. It sure doesn't seem like there is any good solution to this, only a bunch of bad solutions that millions of dollars are being spent every second trying to decide which of them is the least bad.
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Aug 24, 2009 23:27
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Samurai Sanders posted:So have you traffic engineers been paying any attention to the Alaskan Way viaduct fiasco over here in Seattle? We're having an election right now and the Mayoral candidate who may very well win has "no tunnel!!" as basically his entire platform. It sure doesn't seem like there is any good solution to this, only a bunch of bad solutions that millions of dollars are being spent every second trying to decide which of them is the least bad. I make a point never to complain about studies, because spending a penny to study something will save you a dollar in the long run. In a case like this, I'd go with what the ASCE and ACOE recommend, but I'm not sure if they have an official stance. If I could choose, I'd have the viaduct torn down and replaced with capacity improvements on I-5 and transit additions. A nice avenue with a tram would be an excellent replacement, despite handling less capacity. If you're going to build a tunnel, you're better off with more lanes since it's impossible to expand it later. 2 lanes in each direction is just anemic, and the corridor could be just as easily served in cheaper ways. Heck, get some more mass transit up there. Get rid of that joke of a monorail and build a nice integrated system.
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Aug 24, 2009 23:42
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Well, we have our new light rail, which doesn't connect north or south Seattle with each other, or east and west Seattle with each other, or go all the way to the airport (yet) or any other big thing down south, like Southcenter mall, or...
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Aug 25, 2009 00:16
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At least the buses are free downtown, right?
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Aug 25, 2009 00:24
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This may be unrelated to your field, but what brought on the font change in overhead signs on highways? Are they being changed out as-needed, or is there a general deadline to all of them being switched from FHWA to Clearview?
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Aug 25, 2009 01:14
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fedoras posted:This may be unrelated to your field, but what brought on the font change in overhead signs on highways? Are they being changed out as-needed, or is there a general deadline to all of them being switched from FHWA to Clearview? The MUTCD allows the use of many fonts, though there are some calls to introduce Clearview in the proposed changes. My state isn't changing over. I think that they're going to wait for the final rule on whether we're sticking with 40 feet visibility per inch of letter height or switching to 30. It's all up in the air and will be for a couple years, probably. As to what brought on the change, as the name implies, Clearview is more legible at distance. Samurai Sanders posted:Well, we have our new light rail, which doesn't connect north or south Seattle with each other, or east and west Seattle with each other, or go all the way to the airport (yet) or any other big thing down south, like Southcenter mall, or... Long as it has more than two stations!  smackfu posted:At least the buses are free downtown, right? Free buses are a really great idea. I lived in Compiègne, France, for about 5 months. The city levies a special tax on the local businesses, and this tax pays for five bus lines throughout the city. I don't think I was ever farther than 1/2 mile from a bus line. Having free bus service is an amazing convenience: don't have to worry about which door to enter, or to have the right change, or even carry a wallet! The businesses didn't mind paying, because Compiègne is a coveted market, and the downtown area was all but blocked off to cars with parking scarce. The free bus network is now an essential part of Compiègne's business and character.
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Aug 25, 2009 02:20
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Cichidae - if you haven't heard, Google Maps has added traffic information from arterial roads using opt-in data from smart phones. They basically erase the start/stop locations and anonymize the data, then use it to generate the live traffic data. Is this the sort of information folks in your field already have, or will it help you to better design your local traffic systems? Is there precident for using crowdsourced data, or is it too untracable to be of use? Any other thoughts on this addition?
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Aug 27, 2009 23:14
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Solkanar512 posted:Cichidae - if you haven't heard, Google Maps has added traffic information from arterial roads using opt-in data from smart phones. They basically erase the start/stop locations and anonymize the data, then use it to generate the live traffic data. We discussed this sort of data collection in our ITS class, and since then, it's become a rather profitable venture. Previously, the only way to get origin-destination data was to use probe vehicles, basically volunteers who would give us their schedules and routes. There were some plans to use real-time GPS to track some well equipped probes (state cars or buses, for example). The ubiquity of cell phones has really changed the state of the art, and it's not just smart phones. It's possible to track pretty much any cell phone to within a few blocks, and that data could be collected quite easily. Of course, there was the privacy issue, which is mostly circumvented by opting in. So how does this help us? Well, back in the TMC, we used probe cars, and eventually started buying speed/volume/occupancy data from a company called traffic.com, owner of a few hundred real-time detectors all around the state. I'm not sure of the exact price, but I'd wager we paid something on the order of $100,000 per year for that data. Connecticut used the same method, buying the data from a private provider. Well, we looked into the options, and getting the cell phone data you're talking about is over an order of magnitude cheaper. I'm not sure if that includes origin/destination modeling or not, but it's a big improvement either way. Being untraceable is actually a benefit, as we're always going out of our way to avoid privacy issues. The public sector seems to be mired in bureaucracy; all the same, I'd be surprised if we haven't already switched over. I've got nothing against this type of data collection, as long as it's anonymous and the participants know it's going on, but I'm afraid there'll be a leak or some phone company will make it opt-out, and that's going to make a media shitstorm centered around the DOT. Only time will tell!
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Aug 28, 2009 00:04
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Why does Belgium have lights for all of their highways? It seems terribly expensive and wasteful. Also, check this interchange out. I've seen a few of these in Germany and Austria. Got to love roundabouts! (this one is right by the first autobahn rest stop ever, built on the Cheimsee under Hitler's direct supervision) 
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Aug 28, 2009 15:18
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Gail Wynand posted:Why does Belgium have lights for all of their highways? It seems terribly expensive and wasteful. I'm not sure about Belgium specifically, but here, we have lighting warrants. The road has to meet certain conditions before lighting can be implemented. As you might expect, lighting up a freeway improves safety. Yes, it costs a good deal of money to keep them lit, but the past couple decades have seen some impressive increases in lighting efficiency. It all comes down to a cost/benefit decision. If you can pay 1 million euro a year to save 1 life, will you do it? 2 million? 10 million? quote:Also, check this interchange out. I've seen a few of these in Germany and Austria. Got to love roundabouts! (this one is right by the first autobahn rest stop ever, built on the Cheimsee under Hitler's direct supervision) Yep, all it's missing is another roundabout on the left side, and it'd be a classic European interchange. Reading the French driver's manual, I found out that a big reason they put roundabouts at the foot of ramps is that they provide an excellent mental transition from freeway to local roads. Otherwise, velocitizing (fancy word for "going faster than you think you are") tends to occur.
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Aug 28, 2009 17:27
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Great thread, just spent the last few days going reading through it all. What is your opinion on this traffic circle? http://maps.google.com/?ie=UTF8&t=h&ll=33.789821,-118.142418&spn=0.003295,0.003884&z=18 Anyone that lives in Long Beach CA knows about this and it may be the biggest one around for many miles (any SoCal goons know of anything similar?). Like many have mentioned, there are so few traffic circles around this area no one seems to know how to drive on and you can get lots of people stopped at the entrances for long periods. I live pretty close to it but don't have to drive on it very often. It is always quite the adventure.
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Aug 28, 2009 20:44
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