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Choadmaster posted:This reminds me... I live in So. Cal, so snowplows aren't typically an issue, but when I do go somewhere in CA where plows are used (mountains) the pavement markers (reflectors, etc.) are placed into a grooved depression that leaves them easily visible, but deep enough that a plow can pass right over. There's the cost, they'd have to be dug up and replaced with each resurfacing, and any recessed areas tend to get filled with sand very quickly. They also tend to turn into puddles, hampering their reflection and causing pavement deterioration. It'd be possible to make the entire dome flush with the surface, but then it would just be a circle, and why not just use stripes if you're going through all that trouble?
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Aug 19, 2009 17:33
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nm posted:As i understand it, the signs are needed in some states (CA notibly due to anti-speed trap laws) to allow the use of radar/laser/timing. If there are so many people who don't understand that they could actually be ticketed thanks to an airplane, the deterrent isn't as effective as it could be. Perhaps a public info campaign could help seed the fear. Remember, if some people keep speeding and some drive the limit, it's more dangerous than if everyone were speeding. quote:Fun fact, in germany, cars are required by law to have speedometers that won't read high for any wheel combination possible. This results in they reading much lower than standard. If anyone has a VW, find a cop friend and try it with thier radar gun or use a GPS device (not that accurate). You're likely doing 60mph when it shows you're doing 65. I told this to my BMW-driving coworker this morning and he got REALLY pissed-off. he said that this would be impossible due to the different wheel sizes available, which isn't a very strong argument at all. Do you have a link I could show him about that law, even if it's in German? I can translate. Edit: VVVVVVV SlapActionJackson posted:I'm pretty sure "any wheel combination possible" just means any wheel/tire configurations sold as OEM. Cichlidae fucked around with this message at 17:46 on Aug 19, 2009 |
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Aug 19, 2009 17:37
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I'm pretty sure "any wheel combination possible" just means any wheel/tire configurations sold as OEM.
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Aug 19, 2009 17:40
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horseblow.avi posted:A bit of an older post, but just some info from someone who drove the I-80 Donner Pass every winter weekend for 7 years (commuting snowboard instructor). Most of the upper elevation portion of I-80 is actually concrete already. My observations are that the road just gets beat to death from chain bearing trucks. The right lane is always more beat up than the left lane/s. Yeah, there's very little that could be done about that, sort of digging a tunnel through the mountain or embedding heaters in the road and banning chains. Hey, wait a minute... that's actually a decent idea. Expensive, sure, but it's got to be cheaper than replacing the pavement every couple years. Any idea if CalTrans has tried this already, or why it wouldn't work?
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Aug 19, 2009 17:43
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Cichlidae posted:Cons of night work: Are moths seriously a problem for construction workers? We're talking about normal moths, right? Not like.. giant flaming vampire moths; those are a problem for everyone.
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Aug 19, 2009 18:31
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Vanomaly posted:Are moths seriously a problem for construction workers? We're talking about normal moths, right? Not like.. giant flaming vampire moths; those are a problem for everyone.  For content: OP, it's time to play Stump the Chump! (If you're not a Car Talk listener, know that I mean "chump" in the most affectionate of ways.) Here's my alma mater:  Can you tell why the two main drags/parking lots within the campus go at wacky angles? All that property was bought in one chunk, so they could've laid it out in a nice gridlike fashion. Why didn't they? Here's another, zoomed-out picture if you need a hint. Note that the red line extends to another, wholly unrelated college campus. https://wi.somethingawful.com/e1/e1a719766f12fe0d257f0fb01bd870c7c55a7f4a.jpg
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Aug 19, 2009 21:10
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Heh. That reminds me of this, particularly the bottom pic: http://www.kubiss.de/kulturreferat/reichsparteitagsgelaende/englisch/grosse_strasse.htm
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Aug 19, 2009 21:24
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Cichlidae posted:Yeah, there's very little that could be done about that, sort of digging a tunnel through the mountain or embedding heaters in the road and banning chains. Hey, wait a minute... that's actually a decent idea. Expensive, sure, but it's got to be cheaper than replacing the pavement every couple years. Any idea if CalTrans has tried this already, or why it wouldn't work? As for a heated road, I have no experience with them but I could see that it might work in conjunction with plowing. Chains would still need to be required up until the heated portion though. How much would 16 miles of heated roads cost to put in? And how much to heat the road per hour? Cichlidae posted:There's the cost, they'd have to be dug up and replaced with each resurfacing, and any recessed areas tend to get filled with sand very quickly. They also tend to turn into puddles, hampering their reflection and causing pavement deterioration. It'd be possible to make the entire dome flush with the surface, but then it would just be a circle, and why not just use stripes if you're going through all that trouble?
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Aug 19, 2009 21:30
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Wikipedia says that campus used to be an air force base, so I would guess that red line is a former runway
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Aug 19, 2009 22:10
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Vanomaly posted:Are moths seriously a problem for construction workers? We're talking about normal moths, right? Not like.. giant flaming vampire moths; those are a problem for everyone. No, that was a joke  Moths are a pain in the rear end, though, when you have a giant spotlight behind you.JacquelineDempsey posted:
Looks like a runway to me. UConn's football stadium was built at the end of a runway, and they use the tarmac as a parking lot. Pointing toward another campus is probably coincidental.
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Aug 19, 2009 22:28
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smackfu posted:Heh. That reminds me of this, particularly the bottom pic: drat, I wish we had a few of those around here. A nice straight slab of right of way, with lots of development all around? Looks more like a 12-lane freeway, train lines, and pedestrian mall to me!
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Aug 19, 2009 22:32
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Cichlidae posted:
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Aug 19, 2009 22:39
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Cichlidae posted:No, that was a joke You and Socket Ryanist are correct (though SR cheated and used Wikipedia, so no point for you)! But specifically, both campuses are located on parts of what was once Mitchell Field, a WW II base. They flew big-rear end bombers out of there. Big-rear end bombers need big-rear end runways --- and deep ones, to bear all that weight. IIRC, those strips are at least 6 feet deep of solid concrete. Way too much effort to dig all that up, so they kept 'em as is where they could. No coincidence; Nassau County Community College's oddly-angled strip is probably part of the same huge runway, as it was also part of Mitchell Field. If you spot the checkered-roof buildings north of Hofstra, those are old hangars (now a cool airplane museum). Thanks for playing!
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Aug 19, 2009 22:41
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horseblow.avi posted:Regarding tunnels, I think part of the problem is that the distance that would need to be covered by a tunnel is just too great. Chain control is implemented from Kingvale to Truckee at the very least, which is 16 miles. It's often a hell of a lot further than that. Yeah, I wasn't suggesting it be considered. Tunnels in the US are quite expensive; we had someone do a study of a 1/3 mile long tunnel in Middletown just for kicks. The estimated price? $10B to construct, another $500M a year to maintain. Thanks, but no thanks. quote:As for a heated road, I have no experience with them but I could see that it might work in conjunction with plowing. Chains would still need to be required up until the heated portion though. How much would 16 miles of heated roads cost to put in? And how much to heat the road per hour? I'm sure something similar has done. In-pavement driveway heaters could be scaled up, and runways probably have a similar system. As to how much it would cost, I have no idea. I don't even know the thermal conductivity of concrete. quote:I've only seen this done on less traveled, small mountains. The pitch of the road keeps sand and water from filling or pooling in the groove. These same roads are usually maintained with tar snakes instead of constant repaving. Ah, alright. Those would be pretty useful to keep people from accidentally running off the road, then! Our roads here generally are built with 4% and lower grade, going up to 7% occasionally, and higher on short stretches. That's not enough to let something like that drain, unless there was a trench leading downhill out of it, but that'd be an expensive pain to construct.
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Aug 19, 2009 22:45
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Samurai Sanders posted:I don't think these graphs succesfully capture the massive volume of traffic during peak times that this particular road has to deal with, even when two or three lanes of it aren't closed for construction. Maybe the engineer just said, "gently caress it, it's going to be congested one way or another." Different states have different regulations on when a lane closure is allowed. Here's how we do it for freeways in Connecticut: 1) Get hourly counts for an average week on the road in question. 2) If it's a major commuter route, cross out 6-9 am and 3-6 pm on weekdays. 3) If it's a major beach route, cross out Saturday and Sunday peaks. 4) Highlight every hourly volume below 1500 (1800 for roads that don't allow trucks). During these times, the road can be closed to one lane. 5) Highlight every hourly volume between 1500 and 3000 (1800 and 3600). These are times when two lanes must stay open. 6) Repeat until all hours are filled in, consolidate similar days. 7) Put that data into a legally binding chart that goes in the contract. If the contractor starts early or ends late, he can be charged up to $100,000 an hour in liquidated damages.
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Aug 19, 2009 22:50
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JacquelineDempsey posted:You and Socket Ryanist are correct (though SR cheated and used Wikipedia, so no point for you)! But specifically, both campuses are located on parts of what was once Mitchell Field, a WW II base. They flew big-rear end bombers out of there. Big-rear end bombers need big-rear end runways --- and deep ones, to bear all that weight. IIRC, those strips are at least 6 feet deep of solid concrete. Way too much effort to dig all that up, so they kept 'em as is where they could. Quite cool, I love history like that. Looking at the past can explain some pretty weird current circumstances. The fact that the tarmac was nigh-indestructible reminds me of the Fliegerabwehrkanonetuerme in Germany. Built to house FLAK, they were made of massively thick reinforced concrete up to 10 feet thick. They're so large that demolition is cost-prohibitive, so they're left to rot as reminders of the past. At least you can DO something with an old runway.
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Aug 19, 2009 22:54
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Every single highway onramp in Pennsylvania is like, 20 goddamn feet long and usually encourages me to drive across town to get onto the highway on the 30 foot onramp so I don't loving die. Why can't our onramps be longer?
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Aug 19, 2009 23:28
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Sockser posted:Every single highway onramp in Pennsylvania is like, 20 goddamn feet long and usually encourages me to drive across town to get onto the highway on the 30 foot onramp so I don't loving die. Money! Lengthening ramps requires moving roads and bringing the rest of the freeway up to spec, both of which are immensely expensive. Lengthening acceleration lanes requires buying right of way, doing a mill and overlay on the stretch of freeway, and widening bridges. Not cheap. If you'd like a more detailed discussion, you can post some pictures of examples and I'll work my engineering magic to try to fix them; we haven't done that in a few days.
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Aug 19, 2009 23:46
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How do traffic lights actually work. Is it a magnate in the pavement ? Why don't motorcycles trigger some traffic lights. Those rubber hoses laying in the street sometimes across the lanes of traffic. Are they to count how many cars travel on the road per day ? Turd Herder fucked around with this message at 00:59 on Aug 20, 2009 |
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Aug 20, 2009 00:56
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Cichlidae posted:I'm sure something similar has done. In-pavement driveway heaters could be scaled up, and runways probably have a similar system. As to how much it would cost, I have no idea. I don't even know the thermal conductivity of concrete. Cichlidae posted:Ah, alright. Those would be pretty useful to keep people from accidentally running off the road, then! Our roads here generally are built with 4% and lower grade, going up to 7% occasionally, and higher on short stretches. That's not enough to let something like that drain, unless there was a trench leading downhill out of it, but that'd be an expensive pain to construct.
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Aug 20, 2009 01:01
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Rd Rash 1000cc posted:How do traffic lights actually work. Is it a magnate in the pavement ? I went into detail on vehicle detection in this post, but your question merits a bit more discussion. In the past, it was common to put a magnetometer in the pavement. We don't do this anymore, because they have a very small detection area. The most common detection these days is provided by inductive loop detectors. Sometimes, they're very obvious, since the saw cuts in the pavement make an obvious square. Prefab loops are placed under the pavement as it's poured, so they're mostly invisible. These loop detectors are inductive, as the name implies. A small current runs through loops of wire under the pavement. When a large metal object passes above the loop, its inductance changes, and the amplifier sends the resulting signal to the controller. quote:Why don't motorcycles trigger some traffic lights. Because of the variable nature of pavement, not every detector has the same inductance, and not all pavement is the same thickness. We try to keep the sensitivity high enough that it'll detect motorcycles, but low enough that it won't get false calls. Unfortunately, we don't have the luxury of running motorcycles across every loop to test them. Some just don't work, and that's a known shortfall of loop detectors. quote:Those rubber hoses laying in the street sometimes across the lanes of traffic. Are they to count how many cars travel on the road per day ? They're hydraulic tubes, and yes, they count cars. With multiple tubes, we can count cars, find their speed, and even figure out what kind of vehicle they are by their wheelbase length.
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Aug 20, 2009 01:19
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horseblow.avi posted:Do you know if a large heated road has been done anywhere in the world? Thinking about it a bit more, I suppose one issue (besides cost) with a heated road is if one section loses power. A person would be driving along at a decent clip and then all of a sudden hit a slick section of road. Yes, but many of our systems are like that. If a signal fails, if a catch basin overflows, if a pothole forms, any of those could cause accidents. I guess it'd come down to a cost/benefit analysis, and probably some electronic failsafes like sensors that light up a warning sign if the pavement drops below freezing. quote:Each turtle actually has its own groove/trench that runs parallel to the road. It's almost like someone put a grind wheel to the road and put the turtle in the lowest point of the depression. That makes more sense; I've seen that done for retroreflective centerline markers up here. Still, white epoxy is much cheaper, so I don't see us going to raised markers anytime soon.
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Aug 20, 2009 01:23
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Cichlidae posted:Yeah, Bridgeport's not even in my district and we constantly talking about it. It's achieved something of a legendary status here, and the single crack house left standing in full view of 95 doesn't help.
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Aug 20, 2009 01:46
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Cichlidae posted:[...] How about this then. This is not in the US but I drive by it quite often, I think I used it once when I realized I had to turn back though it possibly was the next exit. It's at the top of a medium sized hill as coming from the NW so there's already some reduced visibility both ways. There are trees everywhere, the on/offramps slope downhill, and 130 km/h is legal speed on the highway.  To my non-traffic engineer rear end, there doesn't seem to be anything besides the lack of money/motivation preventing this from being improved, but I'd love to see your opinion.
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Aug 20, 2009 02:05
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GWBBQ posted:We drove past this weekend, and it's gone. Harbor point's undeveloped land is all fenced and covered with grass now. Thank goodness. Now we just have to wait 300 years for the industrial waste to infiltrate into the groundwater and some developer can plop down the cash to fix up the brownfield site. I think I read that 12% of Bridgeport's area is too polluted to safely inhabit. Way to go, B-port! mobby_6kl posted:How about this then. This is not in the US but I drive by it quite often, I think I used it once when I realized I had to turn back though it possibly was the next exit. It's at the top of a medium sized hill as coming from the NW so there's already some reduced visibility both ways. There are trees everywhere, the on/offramps slope downhill, and 130 km/h is legal speed on the highway. The easiest way to fix it would be by widening the overpass to add another lane's width. That's pretty expensive, though, so it might be more worthwhile just to knock down a few trees and go with this:  Something like that would cost on the order of $3M. Assuming the volume on the freeway isn't too high, there are probably better things on which to spend that money.
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Aug 20, 2009 02:19
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I've always found this to be an interesting/insane intersection in Waterbury. It's like the opposite problem of too short ramps. http://maps.google.com/maps?hl=en&s...004501&t=h&z=18 The only control on that intersection is that the Chase Parkway at the top has a stop sign. The offramp has people going 50+, around a fairly blind corner, and then you have people crossing their lane both into and out of the road on top. Also, just turning from the offramp onto Chase is hairy since you need to drop speed very fast and hope someone doesn't rear-end you. Here's what I used to see when I was trying to get on the on-ramp from the stop sign. I particularly like how the signs get in the way. 
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Aug 20, 2009 15:01
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smackfu posted:I've always found this to be an interesting/insane intersection in Waterbury. It's like the opposite problem of too short ramps. You'll be happy to learn that that interchange is going to be fixed with the I-84/CT 8 interchange. There have been problems since it was built because of the split diamond between CT 63 and CT 64. Those ramps were originally intended to connect to a freeway there, but since that plan is off the books, we're going to consolidate the two into a much simpler, safer single interchange. Yay! Edit: I grabbed the analysis we did on it back in 2001, and here's what it says about recommended improvements to this interchange: DOT posted:Signalize the intersection of Chase Parkway/I-84 WB exit ramp/Connector Road and extend the exit ramp deceleration length an additional 525 feet It's unsure whether or not it'd be done under the scope of the mixmaster project, but it should happen sooner or later. Cichlidae fucked around with this message at 21:44 on Aug 20, 2009 |
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Aug 20, 2009 17:14
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Cichlidae posted:Quite cool, I love history like that. Looking at the past can explain some pretty weird current circumstances. The fact that the tarmac was nigh-indestructible reminds me of the Fliegerabwehrkanonetuerme in Germany. Built to house FLAK, they were made of massively thick reinforced concrete up to 10 feet thick. They're so large that demolition is cost-prohibitive, so they're left to rot as reminders of the past. At least you can DO something with an old runway. You can do things with the Flak towers. One of the ones in Vienna was turned into an aquarium, and has a giant climbing wall up one side of it (http://www.youtube.com/watch?v=fs0xIFi2qBY). I came across this by accident while wandering through the streets. Pretty awesome to turn a corner and see it.
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Aug 20, 2009 19:16
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Gully Foyle posted:You can do things with the Flak towers. One of the ones in Vienna was turned into an aquarium, and has a giant climbing wall up one side of it (http://www.youtube.com/watch?v=fs0xIFi2qBY). I came across this by accident while wandering through the streets. Pretty awesome to turn a corner and see it. Not a bad choice! I guess there are some uses for monolithic concrete structures. We traffic engineers are super subtle about pavement markings. Everything has to be just so, guiding motorists subliminally like pigeons in a Skinner experiment. Color is a very easy way to keep people on track. For those of you in far-off lands, pavement markings in the USA are generally white or yellow. Yellow markings go to the left of the driver (generally in the middle of the road), and white markings go everywhere else. Blue can also be used to delineate handicap parking spaces. Black is also technically a color, but only when used as a background to make other markings more visible on light-colored pavement. Here are some typical pavement markings! Let me know if you have detailed questions about them. (I did a great job drawing these, wow!)   Edit: Also, those line up too well. It's coincidental, I swear!
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Aug 20, 2009 23:47
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Great thread Cichlidae, I've been learning a lot. I hail from Edmonton and our road system seems pretty well laid out. Lots and lots of diamond interchanges, I guess you can stay clear of most of this trouble with plenty of land and much lower car volumes than some of those interstate intersections. No fun pictures of a completely messed up intersection from me. One thing though, is that almost all of our roads are asphalt. It was only recently that a road was put in with a concrete top, the new ring road. I had always been told that they used asphalt here because of the severe winters and hot summers combined just beat the hell out of roads (or something to that effect). Thus it was better to use asphalt and plan to repair the extensive damage on a product that's designed with a low lifespan anyways, rather than use a more expensive and durable product that really isn't much more durable at all in our climate. And then they put in a concrete road, so I don't know what's up anymore. I do know that I find asphalt to be a smoother more comfortable ride than concrete, as long as the cracks from winter have been repaired in a timely fashion.
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Aug 21, 2009 01:01
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Cichlidae posted:Money! Lengthening ramps requires moving roads and bringing the rest of the freeway up to spec, both of which are immensely expensive. Lengthening acceleration lanes requires buying right of way, doing a mill and overlay on the stretch of freeway, and widening bridges. Not cheap. Here is the on-ramp to Rt. 1 from Broad St. in Philadelphia PA. The on-ramp is at the far left of the picture, midway down. Merging traffic enters the highway on a slight curve and while this may be difficult to see, it has its view blocked by jersey barriers for a good portion of the ramp. Highway traffic is on a steep uphill and coming around a slight curve that crests exactly where the on-ramp ends. It is virtually impossible for freeway drivers to see merging cars and vice versa. People often stop on the ramp making merging even more difficult.  Luckily I had a 6-cyl when I lived in Philly because the process of merging from there is "See anybody? gently caress it. Floor it!". Now with my 4-cyl getting on Rt. 1 at that location would be impossible. What's even better is that the freeway immediately becomes a bridge right after the on-ramp. I cannot imagine how much it would cost to fix that. 
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Aug 21, 2009 01:04
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Morek posted:Great thread Cichlidae, I've been learning a lot. Yeah, that seems to be the general consensus. Like I said, the ACPA representative I met blamed concrete's poor ride quality on the fact that it lasts longer than asphalt, but that seems more like a con than a pro to me. One thing we do use concrete for is bridge decks, since a thinner layer will hold the same load as some thick asphalt, saving space and weight. One of my projects involves resurfacing an asphalt-paved bridge, and it's a huge pain, since traffic volumes have increased. That means we need a thicker course of asphalt, and the bridge can't withstand it. Our solution? wait another few years and see if it gets better 
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Aug 21, 2009 02:41
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Winter Light posted:Here is the on-ramp to Rt. 1 from Broad St. in Philadelphia PA. The on-ramp is at the far left of the picture, midway down. Merging traffic enters the highway on a slight curve and while this may be difficult to see, it has its view blocked by jersey barriers for a good portion of the ramp. Highway traffic is on a steep uphill and coming around a slight curve that crests exactly where the on-ramp ends. It is virtually impossible for freeway drivers to see merging cars and vice versa. People often stop on the ramp making merging even more difficult. Looking at this, there's a lot to fix. No shoulders, that's a pretty big issue. What happens there when someone inevitably gets swiped or rear-ended? From the lane configuration, it looks like it used to be two lanes in each direction, and then they tried to squeeze in a fifth lane between them at the expense of shoulders. If you just wanted to fix the merge, though, it would be quite cheap.  Bingo. A couple grand in paint, your problem is solved. I'll just send the bill to PennDOT... Really, though, they're probably waiting until they have the cash to fix the whole freeway up before doing anything. Maybe you could call and complain, and they just don't realize there's a problem. We're talking about engineers here; who knows how oblivious we can be?
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Aug 21, 2009 02:52
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I thing I fond amazing was the width of the roads in Texas when I was there. Of course I'm sure a lot of this is due to the amount of space, but being from Sydney I rarerly go on anything wider than 2 lanes, with the biggest I've been on probably a 4 lane stretch of highway on the M5. So out of curiosity, what are some of the widest (in terms of number of lanes) that you know of. I would love to see some google map shots of them.
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Aug 21, 2009 03:45
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Cichlidae posted:Cat Tracks... Elephant Tracks... Shark Teeth This is a bit of a derail but dear lord these make me laugh. Who know there was so much whimsy in the naming of road markings? hahahaaa.
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Aug 21, 2009 08:51
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sc0tty posted:I thing I fond amazing was the width of the roads in Texas when I was there. Of course I'm sure a lot of this is due to the amount of space, but being from Sydney I rarerly go on anything wider than 2 lanes, with the biggest I've been on probably a 4 lane stretch of highway on the M5. Canadian route 401 holds the worldwide record with 18 lanes, also getting honors for being the busiest route.  Toll booths can have huge numbers of lanes, too, like I-95 in New Jersey.  The most lanes under my jurisdiction is on I-84 in East Hartford. 14 lanes, maybe 15 if you count on a diagonal.  If we're going to count collector/distributor roads, though, I-84 gets up to 18 lanes a little east of there, plus a bike path.  Do massively wide roads still get congested? Absolutely. Just keep reminding yourself: it is impossible to build a congestion-free road. You could build a 50-lane triple-dual with c/d roads and frontage roads in the middle of the desert, and people would still find a way to fill it up, given enough time.
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Aug 21, 2009 12:19
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Cichlidae posted:Maybe you could call and complain, and they just don't realize there's a problem. We're talking about engineers here; who knows how oblivious we can be?
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Aug 21, 2009 16:02
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I-75/I-85 is fifteen lanes wide where the two Interstates first merge north of downtown Atlanta: http://maps.google.com/?ie=UTF8&ll=33.787155,-84.390836&spn=0.001239,0.004292&t=k&z=18 It drops and picks up lanes through downtown Atlanta, but consistently has a dozen or more lanes (sometimes as many as 16) all the way through the city until it passes the airport on the south side of town, then it drops a few. Some other interesting features of Atlanta Interstates: - The Tom Moreland Interchange where I-85 meets I-285 in northwest Atlanta, often referred to as "Spaghetti Junction," is a five-level stack interchange with fourteen bridges. - "Malfunction Junction" where I-75/I-85 meets I-20 in the middle of Atlanta, is a hilarious maze of ramps and bridges to accommodate the junction itself and various adjacent street exits and entrances on both routes. - The "Cobb Cloverleaf", where I-75 and I-285 meet and connect to US 41 in northwest Atlanta. The intersection actually only has two cloverleaf ramps these days, the others were replaced with flyover ramps at various points. A long collector/distributor road connects the interchange with US 41 (Cobb Parkway) which runs parallel to I-75. If you look close, you can also see an unused ramp stub from northbound I-75 that may one day become a flyover bridge to replace the NB I-75 to WB I-285 cloverleaf. Currently it's being used by GDOT to park trucks and store some of the new signs that are being put up around the Interstates here. - The newest runway and taxiway at Hartsfield-Jackson International Airport that opened in 2006 bridges I-285. (The Google Maps satellite photos of the area predate construction of the runway, so you can see it disappear if you zoom out past the arial photo level...)
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Aug 21, 2009 16:52
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dennyk posted:I-75/I-85 is fifteen lanes wide where the two Interstates first merge north of downtown Atlanta: I don't think I'll ever understand the general public's confusion about interchanges. This one is pretty simple, really. It's just a stack and a basketweave. quote:- "Malfunction Junction" where I-75/I-85 meets I-20 in the middle of Atlanta, is a hilarious maze of ramps and bridges to accommodate the junction itself and various adjacent street exits and entrances on both routes. And this one is just a stack with two of its ramps becoming semidirect, introducing 2 more bridges where they overlap. The only real oddity is the left-hand entrance and exit to local streets. quote:- The "Cobb Cloverleaf", where I-75 and I-285 meet and connect to US 41 in northwest Atlanta. The intersection actually only has two cloverleaf ramps these days, the others were replaced with flyover ramps at various points. A long collector/distributor road connects the interchange with US 41 (Cobb Parkway) which runs parallel to I-75. If you look close, you can also see an unused ramp stub from northbound I-75 that may one day become a flyover bridge to replace the NB I-75 to WB I-285 cloverleaf. Currently it's being used by GDOT to park trucks and store some of the new signs that are being put up around the Interstates here. Ah, that's a very aesthetically pleasing interchange! Since the flyover from 75 S to 285 E makes the loop ramp there obsolete, is it going to be removed? That'd provide an excellent opportunity to add an extra lane to the mainline, since the bridges are already built wide enough. quote:- The newest runway and taxiway at Hartsfield-Jackson International Airport that opened in 2006 bridges I-285. (The Google Maps satellite photos of the area predate construction of the runway, so you can see it disappear if you zoom out past the arial photo level...) Yes, that's the busiest airport in the country, right? Only logical they'd want an extra runway. Runway overpasses are relatively common. --- 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.  Here, you can see the worker installing the signal heads. It gives you a good sense of how big the darn things are. This is a simple diagonal span.  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.  The head controllers aren't plugged in yet, nor are the detectors. It'll be another couple weeks before everything's plugged in and ready to be turned on. Those bus bars around the middle are where the heads themselves get plugged in. Looks like I'm getting a decent signal controller (decent is relative. Remember, it's stupid like all the rest.) There's even Gatorade product placement! Maybe putting a bottle of liquid in the middle of $5000 of electronics isn't the best idea, guys... NO EXC USES Cichlidae fucked around with this message at 17:41 on Aug 21, 2009 |
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Aug 21, 2009 17:38
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Cichlidae posted:Toll booths can have huge numbers of lanes, too, like I-95 in New Jersey. 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. 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. 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. 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! (Yes, I do seem to have a bug up my rear end about tolls. What can I say?)
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Aug 21, 2009 18:02
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