|
Cichlidae posted:I haven't seen that happen yet. They're protected from above by the visor hood, and backspatter from below is minimal considering they're 16 feet above the road. I suppose that in a driving ice storm, they could get coated, or if someone didn't align the slot in the bottom of a tunnel visor properly they could get snow-covered, so yes, that could be a possible drawback for maintenance. And I believe in places where it is a problem (not so much the Northeast cause it's generally much closer to 32F there but the Midwest/Rockies), they've made tunnel visors with a scoop slot on top like this: 
Horse Pepsi fucked around with this message at 16:42 on Nov 20, 2010 |
#
?
Nov 20, 2010 16:39
|
|
|
|
| # ? May 4, 2024 05:28 |
|
|
What's the deal with the slots?
|
|
#
?
Nov 20, 2010 17:55
|
|
|
Large Hardon Collider posted:What's the deal with the slots? Snow that gets blown at the signal head gets redirected down and away instead of piling up.
|
|
#
?
Nov 20, 2010 18:35
|
|
|
I was going to jump in here and point out that high-pressure sodium bulbs are actually more efficient than LEDs, but after reading up on it it's amazing how far LEDs have come in such a short time. 10 years ago you'd have needed 5 times the power to supply an equivalent brightness using LEDs compared to high-pressure sodium. It'll be sad to see the old pink glow of the street lights disappear.
|
|
#
?
Nov 20, 2010 23:10
|
|
|
Digital War posted:I was going to jump in here and point out that high-pressure sodium bulbs are actually more efficient than LEDs, but after reading up on it it's amazing how far LEDs have come in such a short time. Sodium/mercury vapor lights are the nemesis of nighttime photographers everywhere. Good riddance, I say.
|
|
#
?
Nov 20, 2010 23:19
|
|
|
I live right outside a hospital and I have witnessed multiple times firsthand how an approaching emergency vehicle can change a light, even if it's just changed a moment ago. I had an rear end in a top hat moment a while back where I was listening to music too loud and didn't hear the siren and proceeded into an intersection when the light turned green, when it immediately turned yellow again and I was almost clotheslined by the incoming emergency vehicle. It was nice for once to be one of those rear end in a top hat drivers who doesn't get the gently caress out of the way of the ambulance. (People can be pretty dumb.) But anyway, I've always wondered, what is the mechanism that those vehicles have to change the lights and how does it know which way the vehicle is coming from? I heard some VIP government vehicles also have this kind of thing.
|
|
#
?
Nov 21, 2010 15:29
|
|
|
Vino posted:I live right outside a hospital and I have witnessed multiple times firsthand how an approaching emergency vehicle can change a light, even if it's just changed a moment ago. I had an rear end in a top hat moment a while back where I was listening to music too loud and didn't hear the siren and proceeded into an intersection when the light turned green, when it immediately turned yellow again and I was almost clotheslined by the incoming emergency vehicle. It was nice for once to be one of those rear end in a top hat drivers who doesn't get the gently caress out of the way of the ambulance. (People can be pretty dumb.) Some use radios, others use a strobe pulse system (very similar to how cameras trigger remote flashes using their popup flash as a commander). An IR-sensitive receiver on the signal receives a coded message via a series of pulses from a strobe light and changes the lights appropriately until the strobe pattern stops (e.g. the emergency vehicle clears the intersection).
|
|
#
?
Nov 21, 2010 17:25
|
|
|
kefkafloyd posted:Some use radios, others use a strobe pulse system (very similar to how cameras trigger remote flashes using their popup flash as a commander). An IR-sensitive receiver on the signal receives a coded message via a series of pulses from a strobe light and changes the lights appropriately until the strobe pattern stops (e.g. the emergency vehicle clears the intersection). There are also audio pre-emption systems that listen for the siren, which is nice because the emergency vehicles don't need to buy any new equipment. The more advanced strobe pre-emption systems will actually transfer data back and forth, verifying the identity of the pre-empter and keeping a record of who triggers it. The frequency is remarkably specific (14.035 Hz for emergency vehicles if I remember correctly), so it's hard to cheat without purpose-built equipment.
|
|
#
?
Nov 21, 2010 18:02
|
|
|
kefkafloyd posted:Some use radios, others use a strobe pulse system (very similar to how cameras trigger remote flashes using their popup flash as a commander). An IR-sensitive receiver on the signal receives a coded message via a series of pulses from a strobe light and changes the lights appropriately until the strobe pattern stops (e.g. the emergency vehicle clears the intersection). I was stuck at a light for about 15 minutes once because a cop had someone pulled over in the parking lot across the street. The light facing him was green and everyone else had a red. Eventually, he finished the stop, turned his lights off, and everything went back to normal. I guess this must have been one of the strobe pulse systems?
|
|
#
?
Nov 21, 2010 18:26
|
|
|
you ate my cat posted:I was stuck at a light for about 15 minutes once because a cop had someone pulled over in the parking lot across the street. The light facing him was green and everyone else had a red. Eventually, he finished the stop, turned his lights off, and everything went back to normal. I guess this must have been one of the strobe pulse systems? Sounds like it, yeah. I wonder if the cop noticed what he was doing!
|
|
#
?
Nov 21, 2010 18:30
|
|
|
Cichlidae posted:There are also audio pre-emption systems that listen for the siren, which is nice because the emergency vehicles don't need to buy any new equipment. The more advanced strobe pre-emption systems will actually transfer data back and forth, verifying the identity of the pre-empter and keeping a record of who triggers it. The frequency is remarkably specific (14.035 Hz for emergency vehicles if I remember correctly), so it's hard to cheat without purpose-built equipment. Yup, the two-way systems started getting a lot more popular after people figured out the holes in the dumb ones. The audio pre-emption systems must be pretty hard to engineer, given the range of emergency sirens out there. On the surface it's the most obvious one, but I know lots of cops around here who don't turn their sirens on unless absolutely necessary, which is highly annoying to me as a driver.
|
|
#
?
Nov 21, 2010 19:17
|
|
|
Oh! That explains why I can make lights change at night by blinking my headlights. I'm frequently driving around at night and having to sit at a red light at 2 am when there's nobody else coming is a pain, I didn't realize that was there because of emergency systems though.
|
|
#
?
Nov 21, 2010 21:31
|
|
|
Vino posted:Oh! That explains why I can make lights change at night by blinking my headlights. I'm frequently driving around at night and having to sit at a red light at 2 am when there's nobody else coming is a pain, I didn't realize that was there because of emergency systems though. You'd have to be extremely precisely to hit it at the right frequency. More likely it's just a coincidence, and the light was going to switch over whether or not you flashed the lights. Some signals have the detectors set back hundreds of feet so that the light changes just before you arrive.
|
|
#
?
Nov 21, 2010 21:53
|
|
|
Well I hate to argue with the expert but I'm pretty sure just spamming the blinking at around 3-5hz will make them change. It only works for intersections of a major and not major road, like a 4 lane road next to a shopping center as opposed to the intersection of two 4-lane roads, but in my experience it's pretty immediate after I start blinking the lights. Maybe I'm just imagining it but over years of driving and some unscientific tests I convinced myself it was the blinking. The other thing that can get the light to change is if I back up a single car length. It'll change after a while with a single car on it but if two drive up it'll change immediately, so you can fool it into thinking a second car has arrived just by backing up a bit.
|
|
#
?
Nov 21, 2010 22:06
|
|
|
Hello confirmation bias.
|
|
#
?
Nov 22, 2010 00:08
|
|
|
Crackpipe posted:Hello confirmation bias.
|
|
#
?
Nov 22, 2010 00:10
|
|
|
I remember hearing from a friend about a really interesting british documentary on traffic flow and the British traffic system... like how traffic jams ebbed and flowed through a highway, I think it also dealt with power lines and everything too. ANYWAY! I just found this thread and read like page 1 and 2. bookmarked so I can spend my next few weeks casually trawling the remaining 70+ pages. Can you reccomend any great online docos to watch on anything to do with traffic like that? It's all so fascinating 
|
|
#
?
Nov 22, 2010 03:54
|
|
|
teacup posted:I remember hearing from a friend about a really interesting british documentary on traffic flow and the British traffic system... like how traffic jams ebbed and flowed through a highway, I think it also dealt with power lines and everything too. We've got a ton of things linked in the thread. I'm sure you'll have a very entertaining month or two as you catch up! It's hard to believe the thread's 72 pages long already, wow. If anyone has some time-lapse videos of traffic, I'd love to see them. Coordinated signal systems, in particular, make for good videos, because you can watch the platoons of cars flow through the green band. Here's one video that I find pretty trippy (or it could be because of the goa music I'm listening to).
|
|
#
?
Nov 22, 2010 04:13
|
|
|
Cichlidae posted:We've got a ton of things linked in the thread. I'm sure you'll have a very entertaining month or two as you catch up! It's hard to believe the thread's 72 pages long already, wow. Maybe not what you're looking for, but I've always liked this video of the San Francisco mass transit system. It shows the frequency of buses and light rail vehicles over a 24 hour period. Public transit really is the heartbeat of the city.
|
|
#
?
Nov 22, 2010 08:44
|
|
|
Cichlidae posted:Tungsten carbide. My wife's got a matching one with carbon fiber inlay. I was contemplating asphalt-inlaid stainless steel rings, but engineering is just my job, not my life. Slightly late to the party but I'd considered one as well when I got married. Damned glad I didn't get one though. Last year my finger started swelling up alarmingly and on the emergency advice of a doctor friend I had to cut my ring off with tin snips. Probably wouldn't have been able to do so with the tungsten. Nice soft white gold ftw! But back to the topic at hand, the idea of too-bright LED stoplights came up which reminded me of a problem I've been having along the interstate lately. This is probably a state-by-state thing, but in Connecticut is there any sort of regulation related to the brightness of LED billboards? There's a particular spot in my pre-dawn commute where there are two adjacent ones, both glowing a very bright blue that makes it difficult to focus on the road. In general I wonder what city/state body would regulate them, but I also wonder why they're legal at all. The purpose of the billboards is realistically to distract the attention of passerby, including drivers. So why are super bright semi-animated ones allowed at all? Seems like a stupid unnecessary risk, but I'd be interested to hear of your experiences or knowledge of dealing with them.
|
|
#
?
Nov 22, 2010 15:39
|
|
|
Iridium posted:Slightly late to the party but I'd considered one as well when I got married. Damned glad I didn't get one though. Last year my finger started swelling up alarmingly and on the emergency advice of a doctor friend I had to cut my ring off with tin snips. Probably wouldn't have been able to do so with the tungsten. Nice soft white gold ftw! To remove a tungsten carbide ring, you have to crush it until it breaks  A vice should do nicely in a pinch (har dee har har).
|
|
#
?
Nov 22, 2010 18:19
|
|
|
Iridium posted:Slightly late to the party but I'd considered one as well when I got married. Damned glad I didn't get one though. Last year my finger started swelling up alarmingly and on the emergency advice of a doctor friend I had to cut my ring off with tin snips. Probably wouldn't have been able to do so with the tungsten. Nice soft white gold ftw! When I was growing up in Rhode Island, moving billboards were banned, but the legislature reversed that about 10 years ago. Once companies started putting up LED billboards, it became apparent that people were confusing them for official road signs. The TMC got plenty of calls an angry letters to the effect of "your signs are distracting and I can't believe you would waste public money to advertise!" This alone is proof enough to me that drivers can't easily distinguish between advertising and official signs. Connecticut has legislation about what's proper on signs. For example, you can't have advertising signs that resemble official signs, or including the words "stop" or "slow", visible from the road up to a certain distance. I'm sure, given the right judge, any animated sign could be construed to fall under that description. Unfortunately, it seems this law is seldom (if ever) enforced. Next time you drive down a busy commercial avenue, see how many ad signs say "stop." So, those billboards too bright? Distract you from the road? Call your state representatives and try to get a state law passed banning them. May as well give it a shot!
|
|
#
?
Nov 22, 2010 18:21
|
|
|
KozmoNaut posted:To remove a tungsten carbide ring, you have to crush it until it breaks Hey, the website says that any medical center should have no problem removing it in an emergency, presumably without damaging the underlying finger. The downside isn't that it can't be broken, but rather that it can't be resized if you get fat. If not, well, what were you going to use that finger for, anyway?
|
|
#
?
Nov 22, 2010 18:22
|
|
|
Vino posted:But anyway, I've always wondered, what is the mechanism that those vehicles have to change the lights and how does it know which way the vehicle is coming from? I heard some VIP government vehicles also have this kind of thing.  Cichlidae posted:The TMC got plenty of calls an angry letters to the effect of "your signs are distracting and I can't believe you would waste public money to advertise!" 
|
|
#
?
Nov 22, 2010 21:27
|
|
|
Cichlidae posted:So, those billboards too bright? Distract you from the road? Call your state representatives and try to get a state law passed banning them. May as well give it a shot!
|
|
#
?
Nov 22, 2010 22:48
|
|
|
Edit: ^^^^ No chance of getting anything UConn-related taken down. No state rep wants to risk alienating Huskies fans.GWBBQ posted:That's not how advertising works You'd think people would be able to recognize the difference between a variable message sign and a billboard, too, but no such luck. Yes, the state is sending you the urgent message that you should book your next cruise with Cruise Brothers! Cichlidae fucked around with this message at 23:18 on Nov 22, 2010 |
|
#
?
Nov 22, 2010 22:48
|
|
|
To touch briefly on the yellow before red sequencing, that is how it is done over here in Denmark and since it has always been natural to me I never realised that it might be different elsewhere. The idea of the yellow light is to tell people to be cautious when approaching and of course to get ready when they're sitting at the red. Basically the yellow gives you time to shift into gear. Yellow going to red is also called "Taxi-green" because of their tendency to go blazing through them.
|
|
#
?
Nov 23, 2010 15:26
|
|
|
This is a good, efficient, well-thought-out intersection. The brilliance really shines through if you go through as much of it as is available in Street View.
|
|
#
?
Nov 23, 2010 18:23
|
|
|
GWBBQ posted:This is a good, efficient, well-thought-out intersection. The brilliance really shines through if you go through as much of it as is available in Street View.
|
|
#
?
Nov 23, 2010 20:23
|
|
|
quazi posted:I'd guess that's the closest we Americans have to the Magic Roundabout. Except there's less "round-" and more overlapping-triangle-clusterfuck-about. Park St. should be closed from Lewis St. to the intersection, Hubbels La. should go away entirely, and E. Wall St. and Morgan Ave. should be lined up to make the whole thing a proper intersection. GWBBQ fucked around with this message at 21:40 on Nov 23, 2010 |
|
#
?
Nov 23, 2010 21:36
|
|
|
quazi posted:I'd guess that's the closest we Americans have to the Magic Roundabout. Except there's less "round-" and more overlapping-triangle-clusterfuck-about. I think any discussion of an American Magic Roundabout would be incomplete without mention of East Longmeadow's central intersection:  GWBBQ, you make me really happy that I don't work in District 3. As crazy as the Hartford area is, at least I don't have to deal with crazy intersections in built-up areas and Kevlar-lined signal cabinets. ----- You guys remember this nasty signal plan from last page?  I spent a week untangling that knot, and managed to make everything work much more smoothly in just 5 sequential phases. Nice. That'll be my victory of the month. Here is the area controlled by that signal:  All of the intersections shown there are controlled by a single controller, put there in the 1980s, so we don't have much to work with. We can't even install loops because the whole thing is on a bridge, and we can't cut into the deck. Cichlidae fucked around with this message at 23:51 on Nov 23, 2010 |
|
#
?
Nov 23, 2010 22:55
|
|
|
Cichlidae posted:I think any discussion of an American Magic Roundabout would be incomplete without mention of East Longmeadow's central intersection: I know that intersection all too well. I used to work at a print shop on Shaker Road in East Longmeadow. There's no signalization and there's no real rules on how it works. I cursed it every time. It did have lots of neat old road signs, though.
|
|
#
?
Nov 24, 2010 01:19
|
|
|
I'd have to give a nomination to Towson, MD's central road-hub-thing. Not exactly a roundabout, and not exactly easy to navigate, but considering before it was put in all six of those roads were two-way and the entire intersection was controlled by a single signal...definitely an improvement. I usually just take Bosley (~2 blocks west) to whatever cross-street I need to be on and head in that way, avoiding the clusterfuck altogether. Hardly anyone else does. Bosley's also known as the "Towson Bypass", taking MD45 around the city instead of through it, but the funny thing is it's a 6-lane bypass for a 4-lane road, and it hardly gets used. I can't help but think the whole area would be helped greatly by a great amount of parking on Bosley, possibly on the west side (where there's plenty of room) with ped bridges over the road. Further complicating things, they're turning Washington into a pedestrian-only area for the one block in front of the courthouse, so you can't even cut through that way. This would be fine if people were walking, but most of the traffic to and from the area is by car, and although a lot of it during the day is lawyers & businessmen walking between their offices and the various County buildings, everyone who commutes does so by car. That block on Washington they're converting? It had the one bus stop inside the city area. I don't know how they're planning on helping traffic by 1) taking away a viable driving alternative and 2) making it harder for people to take the bus. Maybe they're hoping it just gets so congested that no one wants to go there unless they absolutely have to. edit: Also a nomination for a sign that does nothing - There's a DNE sign on the other end of the road and you're unlikely (during business hours, at least) to make it to the other end without encountering a car going the right way. Xerol fucked around with this message at 01:45 on Nov 24, 2010 |
|
#
?
Nov 24, 2010 01:40
|
|
|
Roflex posted:I'd have to give a nomination to Towson, MD's central road-hub-thing. Not exactly a roundabout, and not exactly easy to navigate, but considering before it was put in all six of those roads were two-way and the entire intersection was controlled by a single signal...definitely an improvement. On-street parking's tricky. Once you establish it, it's almost impossible to remove later on, because the businesses will defend it as essential to their survival. You're probably right, though, that that street has a lot of capacity. Maybe if they want long-term improvements, they could add on-street diagonal parking and curb bump-outs to reduce the pedestrian crossing distance. Bridges are expensive. Roflex posted:Further complicating things, they're turning Washington into a pedestrian-only area for the one block in front of the courthouse, so you can't even cut through that way. This would be fine if people were walking, but most of the traffic to and from the area is by car, and although a lot of it during the day is lawyers & businessmen walking between their offices and the various County buildings, everyone who commutes does so by car. That block on Washington they're converting? It had the one bus stop inside the city area. I don't know how they're planning on helping traffic by 1) taking away a viable driving alternative and 2) making it harder for people to take the bus. Maybe they're hoping it just gets so congested that no one wants to go there unless they absolutely have to. Making downtown areas pedestrian-only has worked out very well in Europe, but that's generally in centuries-old cobblestone courtyards and streets that draw a lot of pedestrian traffic. The bus stop would probably be moved (I'm hoping), otherwise they would be effectively shooting themselves in the foot. Making the downtown area a bit tougher to travel by car is actually a pretty good goal, as long as alternative bypasses are available. Besides encouraging other modes, it tends to separate local traffic from pass-through traffic. Local businesses may not like that, though. Roflex posted:edit: Also a nomination for a sign that does nothing - There's a DNE sign on the other end of the road and you're unlikely (during business hours, at least) to make it to the other end without encountering a car going the right way. Ok, I can't really find any excuses for that one. Checkmate.
|
|
#
?
Nov 24, 2010 02:22
|
|
|
Cichlidae posted:I think any discussion of an American Magic Roundabout would be incomplete without mention of East Longmeadow's central intersection: That is incredible. Is there some reason it hasn't just been replaced by one huge roundabout? Seems like it would make more sense.
|
|
#
?
Nov 24, 2010 07:12
|
|
|
Cichlidae posted:On-street parking's tricky. Once you establish it, it's almost impossible to remove later on, because the businesses will defend it as essential to their survival. You're probably right, though, that that street has a lot of capacity. Maybe if they want long-term improvements, they could add on-street diagonal parking and curb bump-outs to reduce the pedestrian crossing distance. Bridges are expensive. Well, I meant putting up a garage or something; half the land over there is already county-owned and as far as I can tell doing nothing. quote:Making downtown areas pedestrian-only has worked out very well in Europe, but that's generally in centuries-old cobblestone courtyards and streets that draw a lot of pedestrian traffic. The bus stop would probably be moved (I'm hoping), otherwise they would be effectively shooting themselves in the foot. It seems that's the way they're trying to go; just recently (last 18 months) they took 2-3 blocks of York and turned it from 2 lanes each way to 1 lane + parking each way. Making it even more impossible to get through if there's any traffic whatsoever, and only really adding 40 or so parking spots. All parallel parking, too, and the lanes weren't exactly wide to begin with. Also I've been looking around for historical images of that intersection, so far this is the best I could find but you can just tell how bad it was: http://polaris-fusion.bcpl.lib.md.us/repository/27046339.tif (Seems to be looking south upon York.) e: And another: http://polaris-fusion.bcpl.lib.md.us/repository/5528023.tif From the description: quote:A view of York Road in Towson from the Investment Building looking south. Identifiable in the photo at the left are Hutzlers Department Store, the Little Tavern Carry Out, and the Towson Theater. Seen to the right is Souris' Saloon, the Towson Deli, and Stiebers. The Chesapeake and Potomac Telephone Building can be seen in the middle distance. The buildings seen in the center foreground were demolished in December 1996, to make way for the construction of the Towson Roundabout. Xerol fucked around with this message at 10:00 on Nov 24, 2010 |
|
#
?
Nov 24, 2010 09:57
|
|
|
Cichlidae posted:GWBBQ, you make me really happy that I don't work in District 3. As crazy as the Hartford area is, at least I don't have to deal with crazy intersections in built-up areas and Kevlar-lined signal cabinets. I've been meaning to bring my camcorder and suction cup mount with me and get some videos of particularly terrible spots around here, I'm sure most of the people following this thread would get a laugh from them.
|
|
#
?
Nov 25, 2010 02:06
|
|
|
GWBBQ posted:Please tell me you're not joking and Bridgeport actually had to reinforce their boxes with kevlar. Not a joke at all! Honestly, can you say you're surprised? The overhead signs around Bridgeport also have impressive collections of bullet holes, but lack expensive electrical components that require bulletproofing.
|
|
#
?
Nov 25, 2010 02:49
|
|
|
Cichlidae posted:
Tell me where to go to become awesome at mastering whatever the gently caress this is
|
|
#
?
Nov 25, 2010 06:27
|
|
|
|
| # ? May 4, 2024 05:28 |
|
|
MrBling posted:That is incredible. Is there some reason it hasn't just been replaced by one huge roundabout? Seems like it would make more sense. There is not enough room for the geometry for a proper roundabout for all of those roads' movements without taking some adjoining properties. Pittsfield just finished eliminating its downtown pseudo-rotary that was much like the one in East Longmeadow. They eliminated many of the problematic movements. However, the turn from South street to Bank Row finally has proper signage and markings indicating the traffic from South street to yield at all times to other traffic. However, nobody obeys them. 
|
|
#
?
Nov 25, 2010 13:27
|
|