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Cichlidae posted:Then, you get into New Jersey, and 202 is a BIGSHOT FREEWAY. Where the hell did that come from? 202 is a rural road subservient to another rural road, approaching its terminus, and suddenly it's important. Like some kind of highway Cinderella. At least it has some kind of claim to the throne, unlike I-238. Bitch married into the Interstate family without working for it AT ALL. Anthropomorphizing roads is fun.
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Aug 15, 2012 18:46
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Mandalay posted:At least it has some kind of claim to the throne, unlike I-238. Bitch married into the Interstate family without working for it AT ALL. 238 only got that number because the '80s ran out of prefixes. It's more like Mr. Smith changing his name to Mr. Yznaga because Smith is too mainstream. SO, guess where I was today? You guessed wrong. I was in Salem! Salem has one major intersection, known as Four Corners. It's a signal on two roads that carry freeway traffic from the unfinished Route 11. http://binged.it/NnijaG There was a pretty big rainstorm last night, but it didn't stop us from ripping out the signal, paving the road, and installing a roundabout. That's right! Yesterday evening, this was a signal. This morning, it was a roundabout, and I went out first thing in the morning to check it out.  It's the state's first turbo roundabout. Two two-lane approaches, two one-lane approaches. Drivers were... a bit confused, for the most part, but the professional drivers, like this Coca-Cola truck, had no problem whatsoever. The pavement markings are temporary (another lift of asphalt is going on tonight) and there aren't any lane use signs yet, but it's already operating better than the signal did. SWEET. There were debates as to whether a roundabout would even be able to handle the volumes here. What's even MORE amazing than this whole thing getting done in one night? Google has already updated their maps to show it. https://www.google.com/maps?ll=41.476629,-72.263689&spn=0.004031,0.008256&t=h&z=18 I have no idea how; they must have an attaché who just reads construction press releases and updates things. I will have more pics soon. Just got home from a 12-hour shift and I need to get some food.
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Aug 15, 2012 22:43
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Cichlidae posted:238 only got that number because the '80s ran out of prefixes. It's more like Mr. Smith changing his name to Mr. Yznaga because Smith is too mainstream. This is awesome, just like the whole thread. Good work man!
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Aug 15, 2012 23:06
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Cichlidae posted:238 only got that number because the '80s ran out of prefixes. It's more like Mr. Smith changing his name to Mr. Yznaga because Smith is too mainstream. quote:There was a pretty big rainstorm last night, but it didn't stop us from ripping out the signal, paving the road, and installing a roundabout. That's right! Yesterday evening, this was a signal. This morning, it was a roundabout  whoever made this happen is a real American hero.
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Aug 15, 2012 23:11
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I hope you're happy; they've used up their one good day of getting things done in the year. Those road cones are going to be there for the next 3 months as "construction" continues.
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Aug 16, 2012 00:28
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What the hell is up with that 15mph suggested speed limit, though? Aren't you worried someone's gonna take that literally, and actually drive 15mph, and cause a cascade of accidents?
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Aug 16, 2012 00:34
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grover posted:What the hell is up with that 15mph suggested speed limit, though? Aren't you worried someone's gonna take that literally, and actually drive 15mph, and cause a cascade of accidents? 15 mph is the roundabout's design speed. You can't physically go much faster than 25 in it. Need to yield, anyway. Besides, there are subtle curves in the approaches that slow you down before you hit the yield line.
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Aug 16, 2012 00:49
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Cichlidae posted:15 mph is the roundabout's design speed. You can't physically go much faster than 25 in it. Need to yield, anyway. Besides, there are subtle curves in the approaches that slow you down before you hit the yield line.
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Aug 16, 2012 01:05
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I came across this bouncing freeway sign and thought of this thread. The thread it came from thought it was a little too convenient to have the sign fall as they were passing but the Calgary Herald had a story on it.
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Aug 16, 2012 01:16
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mutagen posted:I came across this bouncing freeway sign and thought of this thread. The thread it came from thought it was a little too convenient to have the sign fall as they were passing but the Calgary Herald had a story on it. A surprisingly common problem. The sign probably got tested fine in a windtunnel, but as soon as water began running down the underside, changing the weight and wind profile a bit, it went crazy. There was a suspension bridge with this problem, the rain added a 2mm 'ridge' on the underside of the main suspension cables when it rained, and the bridge began to oscillate seriously in very mild winds. I hope no one was in the lane to the right of the car, though....
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Aug 16, 2012 02:31
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grover posted:Are all yellow signs reflecting calculated design speeds, or is there a subjective piece to it? Do all designers use the same criteria when setting them? Is there a set g-limit or something? Traditionally, we use a ball-bank indicator and the posted speed is how fast you're going when the ball is at 4%. That way, it takes into account the as-built roadway, not just how it was designed. I've heard of new methods to calculate design speed, but that's still the standard. We often show advisory speeds below the design speed, but that's not advisable, like artificially low speed limits. Not a big deal, anyway, because they're not legally enforceable. mutagen posted:I came across this bouncing freeway sign and thought of this thread. The thread it came from thought it was a little too convenient to have the sign fall as they were passing but the Calgary Herald had a story on it. Now you see why we overdesign these things in Connecticut. That particular failure mode looks like galloping, which is caused by harmonic wind loads beneath the structure, usually from tractor trailers. AASHTO set specifications in 2001 to prevent galloping; that Albertan sign support was probably designed pre-2001, or the Canadian standards are different. Our newest sign supports are limited to 140 feet, which might seem like a lot, but when the posts should be 30 feet off the edge of the road, that's 5 lanes + shoulders. We have plenty of roadways more than 5 lanes wide. Compare the thickness of the structure in the video to one of ours: https://www.google.com/maps?ll=41.5...,213.62,,0,4.04 Those posts are nearly a meter in diameter. Edit: Now that I think of it, galloping is more of a back-and-forth motion, not up-and-down. Could have the same cause, though. Cichlidae fucked around with this message at 03:33 on Aug 16, 2012 |
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Aug 16, 2012 02:44
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Cichlidae posted:Traditionally, we use a ball-bank indicator and the posted speed is how fast you're going when the ball is at 4%. That way, it takes into account the as-built roadway, not just how it was designed. I've heard of new methods to calculate design speed, but that's still the standard. grover fucked around with this message at 03:33 on Aug 16, 2012 |
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Aug 16, 2012 03:28
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grover posted:4% is about 0.33 lateral gees, right? Odd that mentally doubling it seems fast on public streets, but anything less than 3x that on the track feels slow. Now pretend you're driving an old tractor trailer on bald tires with a load of lead weights and glass Christmas ornaments.
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Aug 16, 2012 12:15
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Cichlidae posted:Now you see why we overdesign these things in Connecticut. That particular failure mode looks like galloping, which is caused by harmonic wind loads beneath the structure, usually from tractor trailers. AASHTO set specifications in 2001 to prevent galloping; that Albertan sign support was probably designed pre-2001, or the Canadian standards are different. To clarify, that sign runs across our major N-S city highway, and this happened during a severe thunderstorm with wind gusts from the west up to 100 km/h. Two days before that, we got pummeled with a hailstorm doing millions in damage to unprotected cars.
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Aug 16, 2012 16:56
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Cichlidae posted:Now pretend you're driving an old tractor trailer on bald tires with a load of lead weights and glass Christmas ornaments. And the solenoid for the air brakes leak, so it takes a while to build up pressure no matter how hard you jam on them.
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Aug 16, 2012 17:38
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Is there anywhere I can host a nice wide panorama of the roundabout?
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Aug 16, 2012 23:17
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Cichlidae posted:Is there anywhere I can host a nice wide panorama of the roundabout? imgur? Flickr? picasa?
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Aug 16, 2012 23:38
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ConfusedUs posted:imgur? Flickr? picasa? Let's see how small Imgur makes it. This is the tiny version, anyway; full is about 30 thousand pixels wide.  This is taken from the exact center of the central island. You can tell the island isn't circular; it has a lobe for optimal turbo-ness.
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Aug 16, 2012 23:42
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Cichlidae posted:Let's see how small Imgur makes it. This is the tiny version, anyway; full is about 30 thousand pixels wide. If you right click and select View Image, it's more than large enough. That's pretty awesome.
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Aug 16, 2012 23:48
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So were you able to fit that roundabout in the same space as the old intersection? Also, how bad of an idea is putting a flagpole on the middle of the road? http://lifeinnewtown.com/post/1277475/flagpole-in-newtown-ct
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Aug 17, 2012 01:24
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I can see the news story now. Family of 4 killed in highly patriotic accident
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Aug 17, 2012 01:37
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smackfu posted:So were you able to fit that roundabout in the same space as the old intersection? No, but therein lies some political intrigue I'd probably do better not to mention. Suffice it to say, there are non-traffic reasons for the roundabout's size. smackfu posted:Also, how bad of an idea is putting a flagpole on the middle of the road? I've seen a few towns with flagpole mini-roundabouts. It's an absolutely awful idea, and I can understand the historical reasons for it, but cars and fixed objects do NOT mix. The town is one lawsuit away from either closing the area to traffic or relocating the flagpole. Airconswitch posted:I can see the news story now. If the fates have a sense of humor, the flagpole will be destroyed in a conflagration involving a truckload of fireworks on July Fourth.
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Aug 17, 2012 02:21
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smackfu posted:So were you able to fit that roundabout in the same space as the old intersection? From your article quote:This flagpole, the present one, has been in place for the past 59 years with little deterioration, even after having been hit by a car in 1979 which was traveling at an estimated 55 mph late one night. The injury sustained by the Newtown flagpole was a minor dent. The car was demolished. Such resilience is due to its weight of 2.5 tons and the fact that is buried to a depth of 11 feet below Main Street. So PROUD that the car was completely destroyed while the pole was just fine 
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Aug 17, 2012 16:03
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Knockknees posted:From your article No mention of the car's occupants. If they were REAL patriots they would have avoided the flagpole entirely.
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Aug 17, 2012 16:59
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Cichlidae, I was out this morning watching them pour the precast slabs for I-35. They are going in next Saturday unless we have some further complication arise. It's all on video and we'll have full documentation after the fact, both our own and KDOT's. And I saw the most goddamn amazing thing the other day that you would just crap a 50 mile line of incredulity, but unfortunately I'm bound by a Non-Disclosure but gently caress ME I wish I could talk about this! 
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Aug 17, 2012 19:31
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Chaos Motor posted:Cichlidae, I was out this morning watching them pour the precast slabs for I-35. They are going in next Saturday unless we have some further complication arise. It's all on video and we'll have full documentation after the fact, both our own and KDOT's. I'm gonna be up in Nebraska this weekend. Still a bit far for a visit, unfortunately, but maybe I will see you from the air. Don't expect any replies here until Monday, guys!
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Aug 17, 2012 20:45
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Speaking of uncontrolled 4-way stops, it reminded of these intersections in Tacoma, WA: https://maps.google.com/maps?q=taco...213.69,,0,14.55 I suppose technically it's a roundabout (or rotary? which is the small one again?) but they're far too small to be effective. They're essentially uncontrolled 4-way intersections. No one even slows down, it's terrifying.
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Aug 18, 2012 15:19
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SurgicalOntologist posted:Speaking of uncontrolled 4-way stops, it reminded of these intersections in Tacoma, WA:
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Aug 18, 2012 15:25
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Actually, most of the intersections don't have the roundabout thing, or the signage: https://maps.google.com/maps?q=taco....03,,0,8.9&z=17 Not sure which is better...
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Aug 18, 2012 15:32
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SurgicalOntologist posted:Speaking of uncontrolled 4-way stops, it reminded of these intersections in Tacoma, WA: Looks like a half-hearted mini-roundabout to me. If you they were actually a "thing" in the US it probably wouldn't be a problem.
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Aug 18, 2012 15:35
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I'd say the majority of non-arterial intersections in Seattle and Tacoma are either completely uncontrolled or are controlled only by mini-roundabouts. In practice, it is not all that scary. Most residential streets are effectively one-lane roads and cars tend to take them slowly. You're supposed to yield to traffic approaching from the right, which is only a problem when some rear end in a top hat parks his Escalade right at the corner. Of course, Seattle also has streets like this: http://goo.gl/maps/Numj9
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Aug 18, 2012 20:15
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Jonnty posted:Looks like a half-hearted mini-roundabout to me. If you they were actually a "thing" in the US it probably wouldn't be a problem. My driving instructor took me (and i assume other students as well) over this mini roundabout that was constructed as a mini roundabout but the city hadn't put up the roundabout signs so technically it was a 4 way crossing. He made me treat it as a 4 way crossing because no sign, no roundabout. Really funny when half the people consider it to be a roundabout and half treat it as a 4 way crossing. A few years later the city put in the roundabout signs.
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Aug 19, 2012 12:48
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NihilismNow posted:My driving instructor took me (and i assume other students as well) over this mini roundabout that was constructed as a mini roundabout but the city hadn't put up the roundabout signs so technically it was a 4 way crossing. He made me treat it as a 4 way crossing because no sign, no roundabout. If those examples are mini roundabouts, then what is this thing near my house? http://goo.gl/maps/EeeIt Everywhere I've lived, (up and down the West Coast), thats as close to a normal roundabout as I've seen installed in neighborhoods. Typically on or just on the side of a blind hill too.
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Aug 19, 2012 13:36
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Okan170 posted:If those examples are mini roundabouts, then what is this thing near my house? That is (or should be if it isn't) a classic mini roundabout - they tend to only be at the junction of three roads rather than four in the UK actually. The visibility looks fairly poor but I guess it slows people down.
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Aug 19, 2012 15:03
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I just got back from Nebraska. The whole time I've been a traffic engineer, I thought the chapter on low-volume roadways was completely useless. Nebraska certainly changed my mind about that. I drove 100 miles on a major US route without passing anyone, something I wouldn't have even imagined possible last week. On the plus side, those low volumes meant I covered the 300 miles from Denver in 3 hours, without getting a single ticket. Don't think I even saw a police car. So, here are some observations: - In Colorado, it's not unusual to have fractional route names/numbers. You could live on CR PP 1/2 in Laird, or, my personal favorite, DD.75! - Rail grade crossings are almost completely unprotected, even though train frequency seems to be higher. I imagine, given the low traffic volumes, it's simply not economically possible to protect all the crossings. - You can ride a bicycle on I-76. Right there in the shoulder, dodging tire treads and wild sunflowers. - People actually seemed to keep right except to pass, which is a rare gem in an otherwise unremarkable place. - Tolls on E-470 are done by scanning license plates, which is an excellent idea on a road with a 75 mph speed limit. - Rumble strips scare cows. Centerline rumble strips in passing zones are not a great idea. - Drivers are much more timid. I guess that's to be expected in a more rural area, but I was still amazed I didn't get passed at all, even in towns when it was clear I had no idea where I was going. - Most pavement markings are invisible at night, but there are decent reflectors. - There's overhead lane use signage, as recommended in the MUTCD. They're installed on luminaire brackets. - The pavement is in very good shape despite its age, both concrete and asphalt. Plowing looks to be minimal, and there's probably not much frost heave, as I didn't see pothole patches. Cichlidae fucked around with this message at 12:21 on Aug 20, 2012 |
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Aug 20, 2012 04:11
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Cichlidae posted:I just got back from Nebraska. The whole time I've been a traffic engineer, I thought the chapter on low-volume roadways was completely useless. Maybe you should listen more to Rich Hall, then you would know these things. https://www.youtube.com/watch?v=jVshRfpg7Z4
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Aug 20, 2012 14:02
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Cichlidae posted:- Rail grade crossings are almost completely unprotected, even though train frequency seems to be higher. I imagine, given the low traffic volumes, it's simply not economically possible to protect all the crossings. As was explained to us by representatives of the railway whose train killed a couple friends of ours, protected railway crossings cost $100K up, and most people's lives just aren't worth that much to them. quote:- Rumble strips scare cows. Centerline rumble strips in passing zones are not a great idea. Sure they scare cows, they sound like a predator's roar. 
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Aug 20, 2012 15:17
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Cichlidae posted:- People actually seemed to keep right except to pass, which is a rare gem in an otherwise unremarkable place. I have a theory about why people do sit in the left lane, even while going the speed limit. I'm not well educated in this area, though this thread is really informative, and is turning me into a budding traffic nerd. In SW Virginia (Roanoke) where I am currently living, most people sit in the left lane, and most of those people are going the speed limit, and not passing anyone. A lot of roads in this area seem to be not well planned, even in and around the city area. Below are some examples of two-lane roads whose right lane ends and left lane continues straight into a 1-lane road. Also, most 1 lane roads empty two lane traffic into the left lane when going into a 2-lane road. Note that the speed limit in all city and suburb areas is 35 MPH or under. One or Two roads are over 40, the 581 highway is 55. (It is heavily enforced by State Police because there are clover intersections and weaving and trucks everywhere). The theory is: People sit in the left lane because the two lane stretch which pairs down to 1 lane from the left lane is not long enough to justify changing lanes again less than 5 miles later. Would you attribute the difference in driving behavior to different road design? Here are some explicit examples: Brandon Ave SW, 1-lane to 2-lane Apperson Dr. 2-lane to 1-lane a few miles later Hershberger Rd NW, 1-lane to 3 lane Bonus: the scariest looking intersection I travel through quite a bit Edit: Consider this, drivers in SW Virginia tend to wait until there are no cars coming before turning, maybe it was designed this way because right-turners tend to sit and back up traffic in high-volume traffic areas.
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Aug 20, 2012 17:38
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Chaos Motor posted:As was explained to us by representatives of the railway whose train killed a couple friends of ours, protected railway crossings cost $100K up, and most people's lives just aren't worth that much to them. It's a callous thing to say, but you really do have to think about cost vs benefit when it comes to safety systems. Nothing can be made totally safe, so you have to make a decision about just how much to spend to protect lives. Is a human life worth $1m? $10m? $100m? See http://www.nytimes.com/2011/02/17/business/economy/17regulation.html If it costs $1m to place grade crossing protection on a rail line in a rural area, and those grade crossing would save one life, would it be worth it? What if it costs $20m?
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Aug 20, 2012 17:47
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Well, that was entirely their argument. Admittedly this discussion is 15 years old but if I remember correctly they said they don't actually count any value of the life itself, only the costs to remediate the accident - equipment & signage repairs, etc. When the historical average of costs to remediate accidents crosses the fixed expense to upgrade the crossing, then the crossing is upgraded. In short, unless your crossing generates accidental losses of $(upgrade cost) + $(maintenance cost) / (period), they won't do anything to increase safety. Yes, it's a very dry, business-case driven perspective, but that kind of stand-offish-ness is only possible because these fine gentlemen don't live in the community that experiences these "loss events" and there is very little likelihood of anyone personally paying them a visit. If they were forced to deal with the persons' families on a regular basis, and not living in a guarded manse 500 miles away, they might have a slightly different perspective on these events. Which is one reason I'm throwing out a completely unsupported theory that railways should be owned by the community they cross, and leased to the carrier, thus shifting the responsibility onto the community affected, and the railway simply has to deal with the increased costs to access the safer line. Geographically closer management is better management.
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Aug 20, 2012 18:04
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