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Cichlidae posted:That reminds me, we have quite a few problems with the visually impaired and audible pedestrian signals. You see, like many places in the country, Connecticut has mockingbirds. These delightful avian mimics spend their free time memorizing cell phone ringtones, other birds' songs, and the occasional audible pedestrian signal. Have you made the green engineer mistake of walk resting an audible ped? One of the first systems I set up I unintentionally did this. Let's just say we got some real colorful feedback from the people who had houses right on the corner (Also, they were bells, not the beep beep beep type) During the walk they would ring for 30+ seconds, then go to a don't walk (which rang everytime the light flashed), and if it skipped the cross street, would ring all the way back until the yield point for the main street. 
Nexis fucked around with this message at 00:45 on Sep 16, 2009 |
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Sep 16, 2009 00:43
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Cichlidae posted:With a knowing smile, so pleased that the city's traffic engineers have accommodated his needs, the visually impaired man steps off the curve, directly into the path of an oncoming bus. So it goes. The audible crossing signals we have here have a dual-toned "whoop whoop" that alternately repeats on the two sides of the crosswalk, like so: code:
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Sep 16, 2009 00:51
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Nexis posted:Have you made the green engineer mistake of walk resting an audible ped? One of the first systems I set up I unintentionally did this. Let's just say we got some real colorful feedback from the people who had houses right on the corner (Also, they were bells, not the beep beep beep type) During the walk they would ring for 30+ seconds, then go to a don't walk (which rang everytime the light flashed), and if it skipped the cross street, would ring all the way back until the yield point for the main street. Fortunately, I haven't ever had to set up a new signal, just design them on paper and revise timings in the field. If I so something horribly wrong, there are a few other engineers who get the chance to check my work (and put the PE stamp on it, as I don't have one yet.) I did hear of some complaints about (normally functioning) audible ped signals, though. There's not much you can do for those people, other than to make them familiar with ADA requirements.
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Sep 16, 2009 01:22
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They have audible ped signals outside my old school, North Shore Community College in Lynn. I swear to god, those were the most irritating things I have ever encountered. Not only were they loud enough to hear from the parking garage an entire block away (which I suppose is reasonable), but they picked the most irritating sound they possibly could have devised. I swear they must've used focus groups until they found the noise that made their ears bleed. Edit: Additionally, they only play during the flashing hand phase of the walk period. Der Metzgermeister fucked around with this message at 14:15 on Sep 16, 2009 |
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Sep 16, 2009 04:59
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Cichlidae posted:We touched on this in my ITS class. One interesting feature is that, with the addition of electronic signs with countdowns until the next bus/train/walk cycle, the perception of time is much more leisurely. Most networks I saw in Europe had indications of the next train or two, and I think Brussels' system showed you their locations as well as the time to arrival. They're great until you're been at a bus stop for 5+ minutes with the time arriving being "now". They're still great though. Speaking of crossing signals, the ones in ANZAC seem to have a don't walk tone as well, which would be pretty useful nm fucked around with this message at 07:08 on Sep 16, 2009 |
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Sep 16, 2009 07:05
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Choadmaster posted:whoop whoop ... Tool Maker posted:BEEP BEEP BEEP nm posted:Beep beep boop boop The ones I've seen have a steady, continuous tone for the Walk phase, followed by an intermittent beeping for the Flashing Don't Walk phase. Perhaps, then, my mockingbird example was a bit gratuitious; after all, I think only male mockingbirds sing. The source, thoguh, is true. It was from a complaint we got from a disabled persons' advocacy group. Edit: FDW, not DW. Cichlidae fucked around with this message at 23:19 on Sep 16, 2009 |
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Sep 16, 2009 21:42
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Sgs-Cruz posted:I know, it's not really the government's place to push one transportation method over another, but it's really going to bite America if there isn't some sort of non-car infrastructure in place the next time oil prices spike (and possibly stay high, since the only thing that brought them down this time was the financial collapse of last October). It totally is the government's place, because the government is behind all transportation and land use controls. An excessively unimodal transportation system skews the land uses distribution towards one side or another (of a multi-sided graph) such that, over time, that land use distribution tends to 'cling' to that mode. The example is autocentric suburban sprawl - since cars were the way by which land relationships were shaped, the structures and uses of the land are determined on the scale of automobiles. This can make it more difficult to convert the predominant land use mix over time. Governments can and should intervene to promote a variety of feasible uses, if only to prevent a locking in of one mode over another in a given land use distribution.
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Sep 18, 2009 08:18
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I'd like to tie up some loose ends from earlier, since I promised I'd look into them and promptly forgot. If there are any questions you asked and I didn't answer thoroughly, let me know. Chip Seal I talked with our pavement management specialists, and they said, instead of a chip seal, we're moving toward Novachip. The difference is that Novachip acts much more like full-depth asphalt, so it can hold on to its aggregate and not be nearly as much of a pain to bikers. My biggest problem with Novachip is that we can't use our usual pavement markings. Why's that? Normally, we use 6" white preformed plastic stripes on freeways. They're rolled into fresh asphalt, and the bitumen's heat melts the plastic, embedding them in the pavement. Unfortunately, due to how thin Novachip is (.5-.75 inches, 1-2 cm), it cools much too quickly, and the plastic doesn't melt. That means we need to use shorter-life pavement markings. Bike Path Standards I found out the Department has a whole book full of things to consider when building bike paths, from big things like alignment down to little things like how many bollards to place across the path in order to keep out cars. Consultants and Contractors I said earlier that many contractors are assholes. I'd like to revise this to "almost all contractors." Consultants, who are supposedly working with us, are just as bad. Several months ago, we gave one a detour checklist to fill out. That's a 2-page list of questions that can be answered after a couple drives around the proposed detour route. They came back with 500+ pages of Synchro simulations, a report about the history of the site, and tons and tons of filler. That's about a thousand hours of work they billed us for, and it should have taken 1 or 2. The worst part is that their proposed detour route sucked, and most of the calculations and assumptions were incorrect. And how about those bridge inspections? Someone asked earlier if it was normal for our bridges to be, on the whole, in bad shape. I was filing structure inspection reports today and found one that's rated a 4, which means it needs to be replaced soon. Last inspection, just 5 years ago, rated it a 7 all around. What happened since them? Oh, nothing much, just an 18" full-depth crack. So, how do we miss those things? Well, we hire a consultant to go around and do all the sign structure inspections. A few years ago, we found out that one of the consultants wasn't visiting the site at all, and just made up all the inspections. Oops! You can bet that guy got blacklisted, but here's the kicker. The company head "retired," letting his son take over, and his son renamed the company. Bingo, new contractor, no more blacklist, and they're out there inspecting our structures again.
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Sep 18, 2009 17:35
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Cichlidae posted:So, how do we miss those things? Well, we hire a consultant to go around and do all the sign structure inspections. A few years ago, we found out that one of the consultants wasn't visiting the site at all, and just made up all the inspections. Oops! You can bet that guy got blacklisted, but here's the kicker. The company head "retired," letting his son take over, and his son renamed the company. Bingo, new contractor, no more blacklist, and they're out there inspecting our structures again. Or maybe it wouldn't work because you'd have too high of a burden of proof in showing that it's truly not a new company. Frustrating, anyway.
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Sep 18, 2009 18:09
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Sgs-Cruz posted:This seems like something that the state legislature should be pretty eager to take on. Make a law giving permission for government bureaux to blacklist companies that are really just copies of old blacklisted companies. Money talks. Consultants and contractors give big to politicians (at the state, and especially the local level).
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Sep 18, 2009 23:35
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Sgs-Cruz posted:Or maybe it wouldn't work because you'd have too high of a burden of proof in showing that it's truly not a new company. Frustrating, anyway.
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Sep 18, 2009 23:38
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Sgs-Cruz posted:This seems like something that the state legislature should be pretty eager to take on. Make a law giving permission for government bureaux to blacklist companies that are really just copies of old blacklisted companies. Even if we tried to do something about it, like Nexis says, they have multi-million dollar lake cabins and love to take politicians out for a fishing trip or the like. On the rare occasion that a company is broken up, its engineers just go join other firms and work their magic there. I guess you have to ask, how many employees have to leave a company before it's a new company? There are quite a few other stories of bad consultants and contractors; I'm sure every engineer has one. Of course, there are also horror stories about incompetent state employees, so perhaps I should keep my mouth shut!
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Sep 19, 2009 00:19
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Cichlidae posted:The practice seems to be rare, as this is the first I've head of it Exit 68 on I-84 E for the UConn traffic bro.
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Sep 19, 2009 00:59
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Thanks, Cichlidae, for this thread. I've really enjoyed reading it, and I really appreciate that you've taken the time to thoroughly answer each and every question. I grew up in Texas, but moved to Providence RI 3 years ago, and seeing the vast differences in the way people drive has been quite a learning experience. I'd like to share my most hated intersection. It probably doesn't help that I live in one of the buildings right next to it. I hope this little drawing helps. The lights go in a cycle, counterclockwise from the top. Every road has it's own light, but I just drew in the Atwells and Harris Westbound for convenience.  Basically, people think that the green light when going Westbound on Harris is designed just for them to pull forward 15 to 20 feet and then stop on the crosswalk. OR, people drive right past the light on Harris and stop at the crosswalk anyway, then can't even see the Harris light turn green. This leads to LOTS of cars beeping late at night, as some idiot stops and wonders why everyone is honking. If I'm unfortunate enough to be behind someone who stops there, I just drive past them, in the oncoming lane. Since no other light at the intersection has a green, there's no oncoming traffic. There is, actually, a "stop here on red" sign, but it's completely obscured by a bike lane sign. On days where I have faith in humanity, I imagine that the sign being more visible would help with this intersection's problems. Those are rare days. The other great thing about this intersection is there is NO All Red. The moment one light turns red, the next light turns green. It's the worst if you're going westbound on harris and push the yellow, at the 30 mph speed limit, as it takes several seconds to clear the intersection. I "ran a yellow" one time, and have never done it again, as cars start going the second the light turns. What another poster called a Pittsburgh Left is de-rigeur at this intersection, and I've heard it referred to as a "Little Rhody Left." I see a major accident here once every 6 weeks or so. I don't even bother rubbernecking or peering out my window anymore; I've just gotten used to them.
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Sep 19, 2009 06:12
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Winter Light posted:Exit 68 on I-84 E for the UConn traffic bro. Pagan posted:Thanks, Cichlidae, for this thread. I've really enjoyed reading it, and I really appreciate that you've taken the time to thoroughly answer each and every question. Providence has a ton of intersections like this, thanks to the non-orthogonal layout of the city's streets. Is there a reason why the signal head on Atwells couldn't be pushed back to near the crosswalk? What might really help is a very cheap fix: right cut-off louvers. They're little plastic fins that go inside the signal head and block its visibility from an angle. They shouldn't cost more than $100 to furnish and install. I'm not sure if the signal is state-owned or city-owned (US 6 actually used to go right through there), but a call or two to the authority in charge should fix the problem. If, for some reason, cutoff louvers won't work, there are always optically programmed lenses, but I really don't like those. They tend to get jostled around and end up facing the wrong direction. As to the lack of a red clearance interval, that's pretty sketchy. We mandate at least one second in Connecticut. However, sometimes an engineer (or consultant!) will go muck around with timings and accidentally mess something up, and nobody will catch the problem because it's not on the signal plan. In this case, it's just as likely that the signal controller is 50 years old and nobody really knows how to work it anymore.
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Sep 19, 2009 13:56
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Cichlidae, would you mind commenting on design and use of reversible freeway lanes? I'm curious mostly about where they are/aren't effective, issues with design - mostly your thoughts on the issue.
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Sep 25, 2009 18:02
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Solkanar512 posted:Cichlidae, would you mind commenting on design and use of reversible freeway lanes? I'm curious mostly about where they are/aren't effective, issues with design - mostly your thoughts on the issue. The idea behind reversible lanes is that most freeways have the same number of lanes in each direction. Generally, in the a.m. peak (6-9 a.m.), most traffic is heading downtown, and the trend reverses in the p.m. peak (3-6 p.m.) Because most freeways are static, that means that, during the peaks, one side has additional capacity when the other side needs it most. In a normal situation, we would add more lanes on both sides. However, if space comes at a premium, like on I-93 south of Boston or on many bridges, adding a lane might not be feasible. A reversible lane takes up the usual 12 feet, plus an extra foot or more for shoulders on each side, plus the 2-foot width of barriers. I wouldn't consider a reversible lane without concrete barriers on a high-speed facility, as the risk of head-on collisions would be way too high. However, the practice is common on low-speed roads. Anyway, this means you're taking about 16 feet that would otherwise be allocated to a unidirectional lane and a 4-foot shoulder. One road in England actually has two reversible lanes, with one always staying closed to act as a median, though I'd be tempted just to slap a Jersey barrier down the middle and call it a lane in each direction. As to moving those barriers around, it's generally done with movable barrier, which is short (relatively speaking; most barriers come in 12-24 foot segments) bits of concrete barrier that can be moved at several mph by a purpose-built machine, like so:  source: http://www.paquettes.com/jerry/2005/07/zipper-truck.htmlOther facilities have reversible lanes that are physically separated by permanent barrier on both sides, taking up an additional 4 feet. Use of the lane itself is restricted by bollards, cops setting up barriers, holograms, swarms of angry hornets released at the appropriate instant... So that's the "how" and "why." Now let's discuss the problems! First off, how do you keep cars from going in the wrong direction? On slow, low-volume roads, setting times for each direction works. Some three-lane roads have a center lane that acts as a second through lane during peak hours, and a two-way left turn lane (TWLTL) at all other times. As you can imagine, around the transition times, this could lead to problems. On a freeway, the only way to keep people from killing themselves in head-on collisions is to physically restrict the entrance. For lanes that use a movable barrier, the zipping process itself keeps cars from having head-on collisions. Of course, I'm waiting for someone to buy a left-hand zipper truck to use on a right-hand road, because that would result in some amazing head-on collisions involving the zipper truck itself. For those lanes with permanent barriers, the terminus design is very important. Er, wait, do you use 'terminus' in English? Anyway, you have to clear out the lane first, which means blocking the upstream entrance and having someone drive down to make sure nobody's stuck. The longer the reversible one-way lane, the longer you have to keep it closed, which wastes a lot of potential capacity. Once you're sure it's empty, you can open up the opposite direction and let people use it. This brings to mind another, very important problem: what happens if someone breaks down in a reversible lane with a double barrier? The shoulders are much too narrow to accommodate the vehicle, and there's nowhere to go. Furthermore, everyone behind that car is completely trapped and at very high risk to be rear-ended at 70 mph. A reversible lane with a movable barrier is somewhat less dangerous in this respect. The next problem is major forks. If the road splits, you'll want to allow people in the reversible lane to take either path. This involves either some weaving, if you end the reversible lane before the fork, or extra bridges if you send it along both branches. Whatever, though, that's just money. This is getting pretty long, so let me skip to the conclusion. A reversible lane is pretty far down on the list of things to fix a road. If you absolutely can't add more lanes or build a bypass, if an HOV lane won't carry the proper capacity, if nobody would take a bus or train, if the difference in upstream and downstream directions is really high... then you could consider one. As I mentioned, this is frequently the situation on big bridges, and that's a very common place to put a reversible lane.
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Sep 25, 2009 23:47
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Some freeways in Chicago actually have three roadways, with the middle, reversible roadway having periodic ramps to and from the outer ones.
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Sep 26, 2009 02:20
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Socket Ryanist posted:Some freeways in Chicago actually have three roadways, with the middle, reversible roadway having periodic ramps to and from the outer ones. Yes, a lot of tunnels are set up that way as well. Like I said, it can cause weaving issues if the ramps aren't placed correctly, and can trap people if their cars break down. Reversible lanes are pretty neat, though, and can really improve a road's capacity when implemented properly. What method do they use in Chicago to keep traffic from entering in the wrong direction? Bollards? Edit: It bears repeating. Anything can work if implemented properly, and today's innovations could just as easily become tomorrow's mistakes. Turning a normal lane into a reversible lane is a sign of a deeper problem that can only be mitigated for so long with sneaky engineer tricks. Cichlidae fucked around with this message at 02:43 on Sep 26, 2009 |
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Sep 26, 2009 02:31
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Cichlidae posted:What method do they use in Chicago to keep traffic from entering in the wrong direction? Bollards?
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Sep 26, 2009 02:40
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Socket Ryanist posted:Overhead LED signs I think, possibly with cones? Nothing solid. Probably the physical wall of cars is enough.
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Sep 26, 2009 06:05
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potato of destiny posted:Probably the physical wall of cars is enough. But what about the transition period, when the last cars are clearing out before the other side goes? Aren't people tempted to gun it and try to make it before the other side begins? I know I'd consider it if the lane had just closed, as long as there weren't cops around...
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Sep 26, 2009 16:04
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Cichlidae posted:But what about the transition period, when the last cars are clearing out before the other side goes? Aren't people tempted to gun it and try to make it before the other side begins? I know I'd consider it if the lane had just closed, as long as there weren't cops around... And people like you are why we can't have nice roads in america!!!!  I was pulling into the bank yesterday. The parking lot is one way, cars can only enter in one place and exit in another place. And of course some fat girl with Jersey plates was trying to leave through the entrance, backing up traffic on the main road, and then looking confused and angry at why people wouldn't let her out. I, thinking she was just merely confused, told her "you're going the wrong way down a one way." Not yelling, just saying. She and her passengers all start yelling "So? Who cares!" 
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Sep 26, 2009 16:59
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Pagan posted:And people like you are why we can't have nice roads in america!!!! I was just playing devil's advocate. I don't actually drive like an rear end in a top hat  quote:I was pulling into the bank yesterday. The parking lot is one way, cars can only enter in one place and exit in another place. And of course some fat girl with Jersey plates was trying to leave through the entrance, backing up traffic on the main road, and then looking confused and angry at why people wouldn't let her out. I get that all the time here. There's an exit from a shopping center that's two lanes, one-way exiting. There are two big DO NOT ENTER signs on the outside, mounted on the backs of STOP signs, which goes against the draft MUTCD, but whatever... the point is, it's pretty obvious it's one-way. The stop bar goes all the way across the approach. I usually take a left out of there, so I pull into the left lane so I don't block right-turning traffic. I constantly have to watch out for people turning into my lane, going the wrong way. Once someone did it right in front of them. I gave the driver the death stare, and he just looked back at me like I was the one who messed up.
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Sep 26, 2009 17:22
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Cichlidae posted:I was just playing devil's advocate. I don't actually drive like an rear end in a top hat I know, I was being a smartass. I remember you saying, many pages ago, that the one person in 1,000 who will break the rules is the reason you can't design for the majority. Cichlidae posted:I get that all the time here. There's an exit from a shopping center that's two lanes, one-way exiting. There are two big DO NOT ENTER signs on the outside, mounted on the backs of STOP signs, which goes against the draft MUTCD, but whatever... the point is, it's pretty obvious it's one-way. The stop bar goes all the way across the approach. Although I consider myself a good driver, I ended up going the wrong way last night. There's an intersection in Cranston where the off ramp FROM the highway is right next to the onramp TO the highway. I was distracted by some idiot next to me, and took the first left, not the second. I realized my mistake immediately, and fortunately there wasn't any oncoming traffic. I just drove over the median, back into the correct lane, and paid perfect attention to road signs the entire rest of the drive 
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Sep 26, 2009 17:41
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Pagan posted:I know, I was being a smartass. I remember you saying, many pages ago, that the one person in 1,000 who will break the rules is the reason you can't design for the majority. Traffic engineers even forget that sometimes. A couple of my coworkers have absentmindedly driven up the wrong ramp. Thankfully, we put quite a few hints that you're going the wrong direction: Do Not Enter and Wrong Way signs, the subliminal hint of yellow stripe on the right, reflex reflectors in the pavement in the shape of an arrow pointing toward you, and delineators on the sides of the ramp all work to keep you going in the right direction. Edit: Sorry about Cranston, by the way. Providence and Warwick both get 9 exits on I-95, but Cranston only gets 1! What's up with that? Cichlidae fucked around with this message at 18:48 on Sep 26, 2009 |
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Sep 26, 2009 18:19
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Cichlidae posted:Traffic engineers even forget that sometimes. A couple of my coworkers have absentmindedly driven up the wrong ramp. Thankfully, we put quite a few hints that you're going the wrong direction: Do Not Enter and Wrong Way signs, the subliminal hint of yellow stripe on the right, reflex reflectors in the pavement in the shape of an arrow pointing toward you, and delineators on the sides of the ramp all work to keep you going in the right direction. I was on Rt 10, northbound, so Cranston gets a few more exits. Two real questions instead of anecdotes! First, in areas like that, do you guys make sure it's easy to "escape"? I noticed that the curbs on the median were sloped, instead of square, so it was easier to drive over. When designing stuff like that, do you anticipate that ppl will gently caress it up, and give them ways out? Second, you mentioned that you design roads to handle the 30th worst hour/highest volume. So you anticipate that it will be backed up 29 hours. How do you anticipate the highest, lowest, and average volume? Especially for a "new" road, instead of changes to an existing road?
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Sep 26, 2009 21:05
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Pagan posted:First, in areas like that, do you guys make sure it's easy to "escape"? I noticed that the curbs on the median were sloped, instead of square, so it was easier to drive over. When designing stuff like that, do you anticipate that ppl will gently caress it up, and give them ways out?
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Sep 26, 2009 21:32
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Cichlidae posted:That reminds me, we have quite a few problems with the visually impaired and audible pedestrian signals. You see, like many places in the country, Connecticut has mockingbirds. These delightful avian mimics spend their free time memorizing cell phone ringtones, other birds' songs, and the occasional audible pedestrian signal. Ped signals in downtown Sydney have an additional tactile feedback that could be helpful for situations like this. The audible signal is created by a hammer/striker that hits a plate at the front of the signal, creating the audible signal as well as a tactile sensation on the plate. http://www.walkinginfo.org/aps/chapter10_australia.cfm
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Sep 26, 2009 22:08
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Pagan posted:I was on Rt 10, northbound, so Cranston gets a few more exits. We try to keep curbs off of limited-access highways in general, because they can do some nasty things to your car. When they're needed, for example, when there's not a wide, grassy area to the side, or drainage is difficult, we make them mountable. Generally, curbs are either mountable, 4" or less reveal and a sloped edge, or non-mountable, 6" reveal. Anywhere an emergency vehicle might need to go has a mountable curb, though I've heard that fire trucks won't let a 6" curb stop them. They can pop some smaller tires, though. In a general sense, yes, we anticipate that people will gently caress up. That's why we leave extra room to get over after the acceleration lane's ended. In the case of a lane dropped at an exit, we leave some paved space on the right shoulder after the ramp to let people who didn't realize it was a lane drop merge back into traffic. The slope of the grassy bank on the side of a freeway is designed to let cars drive back up without too much difficulty. Even the lanes going around a curve are often made wider to give you more leniency in how you turn. quote:Second, you mentioned that you design roads to handle the 30th worst hour/highest volume. So you anticipate that it will be backed up 29 hours. How do you anticipate the highest, lowest, and average volume? Especially for a "new" road, instead of changes to an existing road? We have a planning division that does all the calculations. In a general sense, volumes will increase 1-2% a year, though they have been declining around here recently. Back in the late 1980s, on the other hand, we were seeing 5-10% increases every year! On top of the base increase in volumes, we take into account the effects of Major Traffic Generators (MTGs), which are big stores, hospitals, housing developments, etc. Obviously, you can only see too far into the future, so we take Planning's numbers with a grain of salt. A 20-year projection will probably be 20% off one way or another. That's why we time signals for current volumes and then tweak timings as time goes on.
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Sep 26, 2009 22:53
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ragzilla posted:Ped signals in downtown Sydney have an additional tactile feedback that could be helpful for situations like this. The audible signal is created by a hammer/striker that hits a plate at the front of the signal, creating the audible signal as well as a tactile sensation on the plate. Those are pretty cool! We have some vibrotactile devices here that work on a different mechanism. Wouldn't it be great (for the handicapped) if we could have an international standard?
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Sep 26, 2009 23:45
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I saw the strangest thing today. It was basically the inverse of the bottom right of this picture you made: You come off the onramp and there's only a lane until the next offramp, which is maybe or forty yards away. It's nearly impossible to safely merge in time, and you pretty much have to wing it and pray. What the hell? (Not entirely sure where it was.)
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Sep 27, 2009 00:01
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Tool Maker posted:I saw the strangest thing today. It was basically the inverse of the bottom right of this picture you made: That's a weaving section, especially prominent at cloverleaf interchanges. The design is substandard, so we try to eliminate them where possible. Here are a couple around the state as examples.    That last one is actually TWO weaving sections stacked on top of each other! Wonderful, eh?
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Sep 27, 2009 00:59
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Pagan posted:Second, you mentioned that you design roads to handle the 30th worst hour/highest volume. So you anticipate that it will be backed up 29 hours. How do you anticipate the highest, lowest, and average volume? Especially for a "new" road, instead of changes to an existing road? Sometimes this leads to weird effects, such as the Braess's paradox, which basically states that adding capacity may actually worsen congestion.
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Sep 27, 2009 03:43
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Nesnej posted:We construct a demand matrix based on demographic data and then use that as the base data in a simulation that balances the load on each traffic link so that it optimizes consumer demand. And then we run the signal warrants and say, "the town really wants a signal here, mind bumping up your projections by 10% on the side street so we can give them what they want?" At least that's how it works here. Maybe you guys have more control over your traffic engineers
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Sep 27, 2009 05:32
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Cichlidae posted:
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Sep 27, 2009 06:12
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quazi posted:The speed limits on those can't possibly be 65, right?! I'm only counting 7 or 8 dotted lines in the road, and I'm not seeing any collectors or distributors. Wow. And by 'great', I mean 'I will drive out of my way to avoid having to get on the highway there during anything close to busy hours'.
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Sep 27, 2009 07:18
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quazi posted:The speed limits on those can't possibly be 65, right?! I'm only counting 7 or 8 dotted lines in the road, and I'm not seeing any collectors or distributors. Wow. I've seen some around Minneapolis that were worse. Busy as hell and yes, 65 MPH. Someone there clearly thought those things were a brilliant idea, because when I was driving around there it seemed like every other on/off ramp was like this. I wish I knew the area well enough to google the worst of them.
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Sep 27, 2009 11:56
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Okay, I looked around Minneapolis / St. Paul for a bit using Google maps. I didn't find the specific really terrible one I was remembering, but I did count dozens of cloverleafs in the space of a few minutes. Cichlidae, I thought you said our grandchildren would probably never see one of those. Apparently they're still building them in Minnesota:  This one is very short, but it doesn't connect right to the freeway, but rather to some separate lane that merges onto the freeway later:  What the hell is up with the little divider on one of the four leafs here?  Lastly, in my explorations of the area I came upon a couple of these. Never seen one before and they look pretty weird, but they also look like they might work pretty well:  Edit: I thought imageshack was supposed to be the preferred site to use here? Doesn't seem to work in any case. Switched to tinypic... Edit edit: I see even that site's name seems to be a no-no now. Guess I'm out of the loop. Choadmaster fucked around with this message at 12:45 on Sep 27, 2009 |
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Sep 27, 2009 12:38
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| # ? Apr 28, 2024 12:47 |
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Imageshack has been banned since around 2007 when the webmaster decided to be a huge prick. Most people use either waffleimages or tinypic now.
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Sep 27, 2009 14:30
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