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Has anyone read this book on how cities are mankind's greatest invention? http://marketplace.publicradio.org/display/web/2011/02/17/pm-why-cities-are-mankinds-greatest-invention/
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# ? Feb 18, 2011 00:33 |
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# ? May 10, 2024 10:55 |
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Cichlidae, can you tell me everything you know about shared tram/road right of ways and what different signaling and turning lane issues and such they require? TELL. ME. EVERYTHING! Baronjutter fucked around with this message at 01:05 on Feb 18, 2011 |
# ? Feb 18, 2011 00:46 |
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Baronjutter posted:Cichlidae, can you tell me everything you know about shared tram/road right of ways and what different signaling and turning lane issues and such they require?
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# ? Feb 18, 2011 01:57 |
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Baronjutter posted:Cichlidae, can you tell me everything you know about shared tram/road right of ways and what different signaling and turning lane issues and such they require? Well, let's see. We can split trams into three different categories based on their position: median, lateral, and separate right-of-way. Each has its own challenges. A lot of what we know about trams can also be applied to Busways, so you may want to check out TCRP Report 117 for details. Median: You're going to be restricting left turns. This is actually pretty simple: just make all left turns protected-only, and put in pre-emption to block that phase when the tram is on the way. Lateral: Now it gets a bit trickier, because you have to block one direction of left-turning traffic as well as right turners. This means either posting NTOR everywhere, which will get ignored, or using a red arrow / electronic sign that lights up when the tram is approaching. Phoenix' light rail does this, and it seems to light up about 1/4 mile down the road from the tram's current position. Separate: If the tram track is separate from the road, you're basically dealing with a railroad grade-crossing, and you can either go with gates or just a signal to let you know the tram is coming. Special situations: Trams cutting through roundabouts are commonplace in Europe. Entering traffic yields to circulating traffic, circulating traffic stops for trams. You can have some pretty horrific accidents this way, unfortunately, but the alternative is sticking signal heads in the roundabout. Feasible, but not great for roundabout operations. Another special situation is trams crossing the roadway at acute angles, which I also saw a lot in France. They generally only had one small signal head, too. Run the light, get creamed. It's survival of the fittest! And for one more special situation, trams sometimes share pavement with traffic (very common in Europe). In that situation, the tram driver has to really pay attention and act more like a bus driver, starting and stopping for traffic and waiting in queues. Obviously not an ideal situation, but narrow pavement leaves few options. I do know a good deal more; perhaps there's something specific you'd like to know about? nm posted:Good old hook turns Go ahead and post one of Melbourne's gigantic signal heads while you're at it. Cichlidae fucked around with this message at 03:34 on Mar 4, 2011 |
# ? Feb 18, 2011 04:22 |
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IOwnCalculus posted:The HOV lanes around AZ are all free entry/exit, and are only actually HOV during rush hour. Not direction sensitive though - in the middle of town a lot of the freeways back up both directions at both rush hours. Atlanta's HOV lanes are undivided; technically you're not supposed to cross the double white line that separates them from the normal lanes except where it turns to a dashed line, but no one actually pays any attention to that. They also have their own left-hand exits and on-ramps (pretty much a necessity since the HOV lanes are on the left and 75/85 is 6-9 lanes wide in each direction through most of downtown). The Northside Drive HOV exit actually made the news a while back when the driver of a college baseball team bus passing through Atlanta apparently mistook the off-ramp for a through lane and drove straight off the side of the Northside Drive overpass, killing himself, his wife, and some of the students; since then they've changed the signage for the HOV exits and added more warning signs to that ramp in particular. Currently the HOV lanes operate 24/7 and only require two people in the car. Some high-efficiency or alternative-fuel vehicles like motorcycles and biodiesel cars can also use them regardless of number of passengers. However, they're currently converting the HOV lanes on I-85 outside I-285 into high-occupancy toll lanes; vehicles with one or two people will have to pay a toll that varies based on current traffic conditions to use the lanes, while vehicles with three or more people will still be free.
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# ? Feb 19, 2011 14:51 |
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dennyk posted:The Northside Drive HOV exit actually made the news a while back when the driver of a college baseball team bus passing through Atlanta apparently mistook the off-ramp for a through lane and drove straight off the side of the Northside Drive overpass, killing himself, his wife, and some of the students; since then they've changed the signage for the HOV exits and added more warning signs to that ramp in particular. That's horrific! It's lucky that the bus didn't take out some cars on the overpass as well as it flew through. We have off-ramps here that line up perfectly with the through lanes as the freeway turns, though we do try to avoid them, as it looks like there's a signal on the freeway and everyone slows down suddenly. I can't imagine what the bus driver must have been thinking those last couple seconds before he hit the ground... Edit: Example of what I mentioned Cichlidae fucked around with this message at 02:57 on Feb 21, 2011 |
# ? Feb 21, 2011 02:47 |
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Cichlidae posted:Good old hook turns Go ahead and post one of Melbourne's gigantic signal heads while you're at it. This is a smaller one. The tram system in Melbourne works pretty well, driving though, I think the goal is to scare all the cars away.
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# ? Feb 21, 2011 08:39 |
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Cichlidae posted:That's horrific! It's lucky that the bus didn't take out some cars on the overpass as well as it flew through. We have off-ramps here that line up perfectly with the through lanes as the freeway turns, though we do try to avoid them, as it looks like there's a signal on the freeway and everyone slows down suddenly. I can't imagine what the bus driver must have been thinking those last couple seconds before he hit the ground... Here's a Wikipedia article on the accident: http://en.wikipedia.org/wiki/Bluffton_University_bus_accident You can see the new signage and markings in Streetview here. The Wikipedia article has a picture of the old signage, which really could be confusing for someone unfamiliar with the area, especially in the dark. We've got some regular through-lanes that become exits like the one in your picture, especially in town where lanes are added and then removed regularly, but most of 'em are very clearly marked these days with overhead signs, "EXIT ONLY" pavement markings, and shorter striping dividing the exit lane from the through lanes.
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# ? Feb 21, 2011 17:41 |
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Cichlidae posted:Hey, Phoenix got something right! Nice. It's something I can count on every time I come back from a road trip to Los Angeles and/or San Diego - "HOLY poo poo ROADS THAT DON'T SUCK AND FREEWAYS THAT AREN'T BACKED UP AT 11PM".
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# ? Feb 21, 2011 19:18 |
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nm posted:I think I'd just get out of my car and stop driving. And then buy a bike, abandon that one for another bike. Turn gay and paint the second bike green. That's what I'm getting from it at least.
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# ? Feb 21, 2011 20:00 |
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nm posted:
Christ. Can someone explain all this please?
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# ? Feb 21, 2011 21:24 |
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less than three posted:I think I'd just get out of my car and stop driving. Here in Basel, they use the white bars/triangles to signal trams (although they also have a vertical white bar, which I assume means the tram has the right of way). Is it not the same in Melbourne? I only see a simple right turn only signal for regular cars. I'd be a lot more confused if I encountered that on a bike (and wasn't turning right).
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# ? Feb 21, 2011 21:25 |
The leftmost seems to be for a car turning lane. The two with horizontal bars and triangles are for trams, I'm guessing for two separate tracks. (In Denmark, trams used to use horizontal bars for no passing and vertical bars for passing allowed. The tram-style signals are now used for bus-only signals in some places.) The bicycle should be self-explanatory. (The red light is repeated to get it to the same height as the signal for cars. The light below the red bikes is for crossing straight ahead, while the one lit green is for turning right.) Presumably the tram track that has permission to drive is turning to the right, possibly sharing lane with the cars that also have permission to turn. nielsm fucked around with this message at 21:35 on Feb 21, 2011 |
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# ? Feb 21, 2011 21:33 |
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Cichlidae, I have a couple ridiculously nerdy questions to ask you and don't want to poo poo the thread up, I don't have PM's but maybe if you had the time could you shoot me at email at baronjutter at gmail.com ? Thanks!
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# ? Feb 21, 2011 23:57 |
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Baronjutter posted:Cichlidae, I have a couple ridiculously nerdy questions to ask you and don't want to poo poo the thread up, I don't have PM's but maybe if you had the time could you shoot me at email at baronjutter at gmail.com ? Done!
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# ? Feb 22, 2011 00:30 |
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actually now that I've typed up my email I might as well just post it here, who knows the solution and any pictures you post would probably interest the thread. I'm modeling a little city in a stupid online building program/game thingy and I want to get my roads as realistic as possible. What would be the optimal arrangement for 2 minor 2 lane roads meeting and becoming a 4 lane road in a sort of T junction like this. ................... minor----T----4lane .............|......... .........minor....... obviously most of the traffic from the minor road to the south will be turning right, and the minor road to the west will go straight, but the 4 lane will about 50/50 split it's traffic south and west. How would the intersection look and what sort of signage and traffic lights would it need? PS I'm so bad at these forums I don't know for codes or how to post picture or even how to post an emoticon dude but I'm very happy to be here Baronjutter fucked around with this message at 01:04 on Feb 22, 2011 |
# ? Feb 22, 2011 00:57 |
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code:
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# ? Feb 22, 2011 01:00 |
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Baronjutter posted:I'm modeling a little city in a stupid online building program/game thingy and I want to get my roads as realistic as possible. What would be the optimal arrangement for 2 minor 2 lane roads meeting and becoming a 4 lane road in a sort of T junction like this. I can make you a nice diagram. Do you want turn lanes as well? Is it signalized or stop-controlled? How much right-of-way are you working with? I don't know how much control you have in the game, but hey, let me know.
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# ? Feb 22, 2011 01:21 |
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I have tons of room since it's just outside the town in a field area, this would be the main road into and out of the city, pretty much the only way in or out so mildly high capacity, for a town/village road. That would mean it would almost certainly have a signal right?
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# ? Feb 22, 2011 02:32 |
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Baronjutter posted:I have tons of room since it's just outside the town in a field area, this would be the main road into and out of the city, pretty much the only way in or out so mildly high capacity, for a town/village road. That would mean it would almost certainly have a signal right? In the past, we'd have designed a high-type intersection like this one. The design is excellent for high speeds and high capacities, but isn't great for safety. A roundabout would work nicely if the volumes aren't too high, but would be kind of a pain to work with in most games. So here's a nice signalized intersection. Those black dashes are the lane use signs. Everything else should be self-evident.
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# ? Feb 22, 2011 03:57 |
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that's cool thanks, I was thinking of something like that. My lanes aren't divided like that, so the intersection is solid paving without the little grass bits, but otherwise it's almost the same. You've got a fancy program that lets you quickly make these these, or you got the image out of some library of junctions?
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# ? Feb 22, 2011 04:52 |
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Baronjutter posted:that's cool thanks, I was thinking of something like that. My lanes aren't divided like that, so the intersection is solid paving without the little grass bits, but otherwise it's almost the same. Photoshop. But I spend all day looking at roads, so it's mostly drawing from memory. Edit: To clarify, I do it all freehand in Photoshop. None of it's from another source. Cichlidae fucked around with this message at 17:47 on Feb 22, 2011 |
# ? Feb 22, 2011 05:09 |
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How bad has this winter been on CT's roads compared to past years? I don't know if I'm remembering the past few years that well, but the potholes seem a lot more like bomb craters and it feels like an arcade game dodging them. Is there anywhere near enough money in the budget to patch everything up?
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# ? Mar 1, 2011 18:06 |
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GWBBQ posted:How bad has this winter been on CT's roads compared to past years? I don't know if I'm remembering the past few years that well, but the potholes seem a lot more like bomb craters and it feels like an arcade game dodging them. Is there anywhere near enough money in the budget to patch everything up? Malloy is allocating more money than we've previously had to maintenance, so that should hopefully keep things smooth. I'd expect state roads to be in relatively good shape. All in all, it could be much worse; I went to Rhode Island last month, and driving on Route 165 was like a minefield. I spent half the time straddling the centerline so I wouldn't lose a tire at 70... err, 45 mph.
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# ? Mar 2, 2011 01:36 |
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nm posted:
(I collect traffic signals and one of the better sellers to the public is apparently a contractor for NYSDOT or one of the upstate counties (or a "friend" of one) - him or his "friend" posts on FB some of the worst in-person stuff he's seen dealing with signal installations. And then an "after" shot properly done by NYSDOT.)
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# ? Mar 2, 2011 07:30 |
So I notice in california signal heads are almost always hanging from poles, rather than cables. Is this an earthquake safety thing?
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# ? Mar 2, 2011 09:49 |
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Socket Ryanist posted:So I notice in california signal heads are almost always hanging from poles, rather than cables. Is this an earthquake safety thing? Same here in Vancouver. I would be interested to know as well. It certainly looks nicer though.
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# ? Mar 2, 2011 10:21 |
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Socket Ryanist posted:So I notice in california signal heads are almost always hanging from poles, rather than cables. Is this an earthquake safety thing? It's more style than anything. Mast arms are more expensive, because they have big foundations and require a lot of steel and internal cabling, but they look prettier. You can build them to be earthquake resistant; I'm pretty sure ours in CT are bombproof, given how overdesigned they are. Span wire could lead to some resonance in an earthquake, true, but mast arms do as well. I saw some research recently out of UConn that showed mast arms oscillating from a small applied force, and they shake noticeably for several minutes. Their research proposed building dampers into the signal heads, which I'm sure would be incredibly useful in an earthquake as well.
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# ? Mar 2, 2011 13:37 |
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Socket Ryanist posted:So I notice in california signal heads are almost always hanging from poles, rather than cables. Is this an earthquake safety thing? I'm from CA, and I think hanging them from cables looks ugly as sin. I suppose I'm spoiled, but I really hate cables dangling everywhere and ten signal heads in a jumble in the middle of an intersection. But more importantly, as someone said in this thread a couple months ago, the cable-hung ones can often be very hard to see. This seems to be particularly bad when they're stringing them along one cable diagonally across the intersection - the signal head for the rightmost lane is almost always too close to see without leaning forward and explicitly looking up at it.
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# ? Mar 3, 2011 06:23 |
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Cichlidae posted:It's more style than anything. Mast arms are more expensive, because they have big foundations and require a lot of steel and internal cabling, but they look prettier. You can build them to be earthquake resistant; I'm pretty sure ours in CT are bombproof, given how overdesigned they are. Most places that seem to get a lot of wind have mast arms.
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# ? Mar 3, 2011 06:29 |
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Choadmaster posted:I'm from CA, and I think hanging them from cables looks ugly as sin. I suppose I'm spoiled, but I really hate cables dangling everywhere and ten signal heads in a jumble in the middle of an intersection. I also feel this is a perfect opportunity to remind us long-time readers of and introduce new people to schizophrenic traffic light guy from earlier in the thread.
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# ? Mar 4, 2011 01:56 |
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GWBBQ posted:I'm 6'8" and cannot see at least 90% of cable hung traffic lights without bending down and putting my head in the "your neck will be broken by the airbag" region. One of our cars as a sunroof and if I'm the first in line at a light, I can frequently see them just by leaning my head back against the headrest. I haven't heard from my mast-arm-hating friend in some time, unfortunately! We get other crazy emails, but it's just not the same. But hey, I will share this other letter that he submitted online. Again, a long read, but I'm sure you'll remember it for the rest of your natural life. Heck, I'll bold the best parts. Oh my goodness posted:Dear Editor, Yes, this was all posted in a public forum.
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# ? Mar 4, 2011 03:12 |
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Cichlidae posted:endless ramblings of one of CT's finest sweet jesus. Did this make its way to Gov Malloy?
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# ? Mar 4, 2011 03:22 |
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Lobstaman posted:
I can only assume he's seen it at some point; our friend likes to send copies to everyone he can. This was posted in the Hartford Advocate about... 2 years ago? I'm sure parts of it have made it into emails, letters, and manifestos scrawled in urine and blood on walls statewide.
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# ? Mar 4, 2011 03:30 |
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Through that Wild West paragraph, I was worrying Ronald Reagan had risen from the dead and was writing cranky letters to the editor.
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# ? Mar 4, 2011 04:21 |
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Cichlidae posted:Yes, this was all posted in a public forum. That level of crazy: only in Hartford
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# ? Mar 4, 2011 05:58 |
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Derpes Simplex posted:That level of crazy: only in Hartford East Hartford, technically. I have a project right near his house (he puts his address and date of birth in all of his online comments). Thank goodness I'm not installing any mast arms!
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# ? Mar 4, 2011 13:31 |
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What would you do with something like this? http://inapcache.boston.com/universal/site_graphics/blogs/bigpicture/quake1/bp36.jpg
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# ? Mar 11, 2011 20:29 |
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Mandalay posted:What would you do with something like this? Re-sign it as a divided highway?
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# ? Mar 11, 2011 20:37 |
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# ? May 10, 2024 10:55 |
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Mandalay posted:What would you do with something like this? Pretty awesome that it split right down the lines like that.
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# ? Mar 11, 2011 20:42 |