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PittTheElder posted:But isn't "This light is going to turn green in 1s" useful information to me? Sure it'll encourage people to try and peel off right as the light turns green, but those people are always going to do that anyway. Definitively telling me when the light is going to turn seems like a better idea than everyone trying to guess and starting rolling early anyway. It's useful information to you, but when you use it to peel out and get t-boned by someone slipping through a yellow (perhaps because they also saw how much time was left and tried to squeeze it in) then the collision costs the state mucho dinero. Particularly if someone survives and decides that they want to sue the state for putting in traffic signals that contributed to the collision. Increasing lane efficiency by one second is not worth it. PT6A posted:And if it only gives a second's notice, that's just enough to switch from neutral to first anyway, so you're not sitting at a green light as you put your car in gear. I'm guessing the extremely low prevalence of manual transmissions is why the idea hasn't caught on in North America. I'd guess it has much more to do with the legalistic climate of the United States, and I drive a manual car. Kaal fucked around with this message at 07:22 on Feb 25, 2014 |
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Feb 25, 2014 07:09
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Are there any state DOTs (or even local public works departments) that place the pedestrian signal near the lights the drivers actually look at, instead of simply across from the crosswalk? I am the project manager for my community's pedestrian plan, and this is one of the things I'd like to fix. Drivers do such a poor job of noticing pedestrians anyway that it makes sense to at least stick the signal right in front of them. But I'm guessing that our public works department will be more willing to change standards if they see another community is doing the same thing. This is an example of what I'm talking about. I'd like to see the pedestrian signal moved to (or a second ped signal installed at) the left circle, instead of the right circle where it is now. 
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Feb 25, 2014 08:04
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But pedestrian signals are supposed to be for pedestrians. 
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Feb 25, 2014 08:06
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Hedera Helix posted:But pedestrian signals are supposed to be for pedestrians. Pedestrian signals are supposed to signal to every user--whether on foot or in a vehicle--that the pedestrian has the right of way there. When the pedestrian signal is placed so far out of the drivers' view, it induces drivers to make right turns without considering pedestrian right of way.
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Feb 25, 2014 08:12
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Nice Davis posted:Are there any state DOTs (or even local public works departments) that place the pedestrian signal near the lights the drivers actually look at, instead of simply across from the crosswalk? I am the project manager for my community's pedestrian plan, and this is one of the things I'd like to fix. Drivers do such a poor job of noticing pedestrians anyway that it makes sense to at least stick the signal right in front of them. But I'm guessing that our public works department will be more willing to change standards if they see another community is doing the same thing. This is an example of what I'm talking about. I'd like to see the pedestrian signal moved to (or a second ped signal installed at) the left circle, instead of the right circle where it is now. It's an interesting concept, but you'd definitely want to duplicate rather than replace. Drivers and cyclists will be looking for the existing standard placement to indicate a crosswalk. Beyond that, I'd question the clarity of a signal that is so divorced from what it is indicating - looking at the sign (in the center and above) means looking away from where the sign indicates (to the side and down). In the current standard, when you look to where you are turning you will also see the light of the signal and hopefully the pedestrian in question. I'd prefer increasing the viability of that sign in situ rather than separating that association. Personally, I'd suggest something more conventional like crosswalk islands and a narrowing of the intersection. Kaal fucked around with this message at 08:31 on Feb 25, 2014 |
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Feb 25, 2014 08:26
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Red turning into yellow and then green isn't even a thing across the whole of Europe. I don't particularly care for it when driving through Germany 
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Feb 25, 2014 11:19
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I thought that the red/amber - green phase was far too quick in Germany, then again I was only in Cologne so I don't know what it was like elsewhere. I do know that the lights go straight from red to green in Ireland and France. To be fair I'm not that fussed about the red/amber-green thing here in the UK now that I have an automatic. 
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Feb 25, 2014 14:57
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Echo 3 posted:A few old-timey traffic signals in Massachusetts used to use circular red + circular yellow to mean an all-pedestrian phase. The last one that I knew of was replaced with a normal ped signal a few years back, though. There are still several intersections controlled by blinking green lights in Boston.
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Feb 25, 2014 15:05
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PT6A posted:And if it only gives a second's notice, that's just enough to switch from neutral to first anyway, so you're not sitting at a green light as you put your car in gear. I'm guessing the extremely low prevalence of manual transmissions is why the idea hasn't caught on in North America. I doubt it, because the North American car fleet in the early 90s was still pretty handily a majority of manual transmissions. And Europe probably didn't just start using them after that point.
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Feb 25, 2014 15:35
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RadioPassive posted:There are still several intersections controlled by blinking green lights in Boston. I typically see flashing green in front of fire stations, meaning "this light will always be green except when a fire truck is pulling out." Is that type of usage not in the MUTCD? Speaking of Boston, the Globe wrote an article today about the flashing yellow arrow. It's an interesting case that seems to demonstrate a need for one: A two-way street facing an oncoming one-way street, so they don't want to use the green ball because drivers can't actually go straight, but the green left arrow is also inappropriate because you have to yield. http://www.boston.com/news/local/bl...4CqDL/blog.html
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Feb 25, 2014 15:59
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Nice Davis posted:Are there any state DOTs (or even local public works departments) that place the pedestrian signal near the lights the drivers actually look at, instead of simply across from the crosswalk? I am the project manager for my community's pedestrian plan, and this is one of the things I'd like to fix. Drivers do such a poor job of noticing pedestrians anyway that it makes sense to at least stick the signal right in front of them. But I'm guessing that our public works department will be more willing to change standards if they see another community is doing the same thing. In Germany, when there is a conflict like this I've seen an extra yellow flashing light mounted next to the rightmost signal or right-turning signal, which only flashes when both peds and turning cars have a green light. I seem to remember that the peds also get a warning, but I'm not sure about that any more. In the Netherlands there's no special indication for it, they just try to avoid such conflicts and I've only seen them on tight city streets where you'd be watching for cyclists anyway.
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Feb 25, 2014 16:03
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Put an RRFB on the mast arm that goes off whenever peds activate a walk phase relevant to that direction.
Varance fucked around with this message at 16:30 on Feb 25, 2014 |
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Feb 25, 2014 16:25
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Entropist posted:In Germany, when there is a conflict like this I've seen an extra yellow flashing light mounted next to the rightmost signal or right-turning signal, which only flashes when both peds and turning cars have a green light. You'd have something like this: http://goo.gl/maps/ypntZ  Red box: Pedestrian lights and flashing yellow signal for car traffic to warn them when the Pedestrians have a green light. Green Box: -Upper light (yellow-arrow flashing) warns of oncoming traffic having green -Lower light (green-arrow) goes on when opposing traffic and pedestrians have red
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Feb 25, 2014 16:31
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Echo 3 posted:I typically see flashing green in front of fire stations, meaning "this light will always be green except when a fire truck is pulling out." Is that type of usage not in the MUTCD? Flashing green is specifically advised against in the MUTCD: MUTCD, 4D.04.D posted:A flashing green signal indication has no meaning and shall not be used. The flashing greens I see around Boston/Cambridge/Somerville usually denote "green, but yield to any pedestrian." But I'm not really 100% on that, since some of them are placed in locations that don't make much sense for that purpose.
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Feb 25, 2014 17:05
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PittTheElder posted:But isn't "This light is going to turn green in 1s" useful information to me? Sure it'll encourage people to try and peel off right as the light turns green, but those people are always going to do that anyway. Definitively telling me when the light is going to turn seems like a better idea than everyone trying to guess and starting rolling early anyway. Basically your argument is "But it's more convenient for me!" and the traffic design argument is "But it's more dangerous and expensive for everyone!" and so the design's not going to change. Think about it the worst-case scenario from everyone's perspectives: For the driver on the highway who currently has a green, giving them information on how long the green last encourages them to gun it in the last few seconds to "slip by on yellow." People already do this, but if you tell them "you have 5 seconds left of green!" that gives them more time to accelerate and make it through. You can see this happen all the time when you have timed ped. signals that roughly match up with light cycles. The effect is: people driving through the intersection faster, and people driving through the yellow/first parts of red faster and more often. If you'd like, think about how many times you see a pedestrian look at the "9 seconds left!" timer and start sprinting across the crosswalk because "I can totally make it!" and then waving in apology to the cars who are stuck. Drivers would do it too, only they're going 50 where pedestrians are jogging. For the driver stopped at red, giving them information on the coming green light encourages them to start moving before the light has changed to get a jump on things. This already happens when people start creeping into the crosswalk when they think a light will change (if they're not already in the crosswalk), or inching up on the car in front of them, but would get worse if they had more information about it. The effect is: people entering the intersection earlier and faster than they would if their only information was the light. For both those drivers, they rely less on the light and more on other sources of information in choosing when and how fast to enter the intersection. The combination of faster cars and more cars entering the intersection on both sides of the clearance period will make collisions more common (faster, clearance times) and more deadly (faster, T-bone). For the ambulance driver/firetruck/police officer, timing systems are harder to handle with emergency overrides. Sure, you can have the time disappear and the light instantly change, but people are now paying less attention to that, and may already be gunning it to clear the intersection before you are going to be crossing. So overrides are less effective at guaranteeing clear intersections. This slows emergency response times and makes it more likely someone T-bones an ambulance. For the pedestrian, having drivers gun it late on a green or start inching into an intersection early puts them at more risk. While you might think "I'm just going to put my car in gear, not enter the intersection," most drivers are terrible and engineers have to design around worst-case scenarios because the sheer volume of traffic in most places makes those events pretty likely. Check Cichilidae's posts on pedestrian timing & 90-year old ladies or curve diameters and drunk semi-driver capacity for other examples.
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Feb 25, 2014 19:03
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Kaal posted:It's an interesting concept, but you'd definitely want to duplicate rather than replace. Drivers and cyclists will be looking for the existing standard placement to indicate a crosswalk. Yeah, I agree that that's preferable. Kaal posted:Beyond that, I'd question the clarity of a signal that is so divorced from what it is indicating - looking at the sign (in the center and above) means looking away from where the sign indicates (to the side and down). In the current standard, when you look to where you are turning you will also see the light of the signal and hopefully the pedestrian in question. I'd prefer increasing the viability of that sign in situ rather than separating that association. It's a nice thought, but in many many instances the turning driver does not see the waiting/crossing person. I'm guessing you've seen the same thing, hence the use of "hopefully". Kaal posted:Personally, I'd suggest something more conventional like crosswalk islands and a narrowing of the intersection. I'm very much in favor of using the shape of the roadbed to mold driver behavior...way more so than signage and signals. Unfortunately we don't have anywhere close to the money to retrofit existing intersections to a slower/more cautious standard, so I'm exploring signaling options. Entropist posted:In Germany, when there is a conflict like this I've seen an extra yellow flashing light mounted next to the rightmost signal or right-turning signal, which only flashes when both peds and turning cars have a green light. I seem to remember that the peds also get a warning, but I'm not sure about that any more. In the Netherlands there's no special indication for it, they just try to avoid such conflicts and I've only seen them on tight city streets where you'd be watching for cyclists anyway. Tank Boy Ken posted:You'd have something like this: http://goo.gl/maps/ypntZ That's an interesting concept. Thanks for posting! Varance posted:Put an RRFB on the mast arm that goes off whenever peds activate a walk phase relevant to that direction. We're trying to get away from signals that require a trigger for a host of reasons, not the least of which is that someone shouldn't have to "ask permission" to make a crossing they're entitled to. Incidentally, our neighboring city just installed one of those at a mid-block crossing and it's bright as hell...you can see it a mile away.
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Feb 25, 2014 19:50
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Arcturas posted:For the driver stopped at red, giving them information on the coming green light encourages them to start moving before the light has changed to get a jump on things. This already happens when people start creeping into the crosswalk when they think a light will change (if they're not already in the crosswalk), or inching up on the car in front of them, but would get worse if they had more information about it. The effect is: people entering the intersection earlier and faster than they would if their only information was the light. I'm totally with you on everything else you wrote, it clearly encourages undesirable behavior. I just don't see how an advance yellow actually does. As you say, tons of people are already trying to anticipate the switch and start rolling into the crosswalk early anyway. That's all guesswork based on what the other visible signals are doing. If anything, I would think that the advance yellow would at least stop the guesswork, while overall not increasing the amount of people entering the intersection early. And if this has been tried somewhere and I'm wrong, I'd love to read about it.
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Feb 25, 2014 19:53
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Yes, it's like a lava lamp.
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PittTheElder posted:I'm totally with you on everything else you wrote, it clearly encourages undesirable behavior. I just don't see how an advance yellow actually does. As you say, tons of people are already trying to anticipate the switch and start rolling into the crosswalk early anyway. That's all guesswork based on what the other visible signals are doing. I don't have any empirical data about it, but I think "some people already do something dumb now, why not let everyone do it?" isn't the best approach when deciding to adopt an advance yellow. Stopping the current guesswork would just let more people try to get a head start. If anything, I think the change from the status quo and adoption of the advance yellow would send a message to US drivers that "there's a new phase at the beginning of the light! You should do something now!" which would encourage people to drift forward.
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Feb 25, 2014 20:51
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PittTheElder posted:If anything, I would think that the advance yellow would at least stop the guesswork, while overall not increasing the amount of people entering the intersection early. And if this has been tried somewhere and I'm wrong, I'd love to read about it. The solution that engineers are adopting is to deter guesswork by implementing hoods on lights so that they are only seen by the drivers that are intended to see them. Of course you can still figure it out, but it discourages people from timing lights, rolling through in neutral, jumping the signal, and other sorts of "pro driving" behavior.
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Feb 25, 2014 22:08
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RadioPassive posted:Flashing green is specifically advised against in the MUTCD: The ones in Vancouver are similar -- they're used at intersections of side streets with major roads, where the side street has no traffic light, only a stop sign (and pedestrian/cyclist buttons). During the green phase on the main street, the lights flash green to indicate that motorists should approach with care, and yield to traffic in the intersection if there is any. Motorists at side streets should only enter the intersection when it appears safe, but if they're in already, they have right of way. Of course, basically nobody knows this, and tons of people go screaming through the flashing greens at speed, then get all upset when they hit somebody on a green light and the courts find them at fault: http://bc-injury-law.com/blog/tag/flashing-green-lights
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Feb 25, 2014 23:21
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SurgicalOntologist posted:Are there any places where there's a "stop unless you're going right" sort of sign? I'm thinking of a situation with a shallow fork on the approach (slight left or slight right), the only conflicting pattern is a nearly-U-turn left-turn that no one ever does unless they're lost, and visibility of the approach is good. MUTCD sez: Option: 09 An EXCEPT RIGHT TURN (R1-10P) plaque (see Figure 2B-1) may be mounted below the STOP sign if an engineering study determines that a special combination of geometry and traffic volumes is present that makes it possible for right-turning traffic on the approach to be permitted to enter the intersection without stopping. RadioPassive posted:Flashing green is specifically advised against in the MUTCD: The MUTCD also forbids red strobes in signal heads, but I've seen a few of them, too. Our compliance rates up here in New England aren't too good overall. Nice Davis posted:Are there any state DOTs (or even local public works departments) that place the pedestrian signal near the lights the drivers actually look at, instead of simply across from the crosswalk? I am the project manager for my community's pedestrian plan, and this is one of the things I'd like to fix. Drivers do such a poor job of noticing pedestrians anyway that it makes sense to at least stick the signal right in front of them. But I'm guessing that our public works department will be more willing to change standards if they see another community is doing the same thing. In some rare cases, we've had electronic No Turn On Red signs that light up during the ped phase. Given that people usually ignore them anyway, I doubt compliance would be very high. Heck, even our RRFB is getting a thumbs down from drivers. I guess Connecticut is just a no man's land for pedestrians. PittTheElder posted:I'm totally with you on everything else you wrote, it clearly encourages undesirable behavior. I just don't see how an advance yellow actually does. As you say, tons of people are already trying to anticipate the switch and start rolling into the crosswalk early anyway. That's all guesswork based on what the other visible signals are doing. Civil engineers are extremely risk-averse, which makes sense when you consider that we have millions of lives in our hands every day. Even if something's proven to be very effective, it takes decades for it to become commonplace. On an unrelated note, there was a bad accident today at one of the intersections where we'd planned safety improvements (but couldn't find the money). The news article doesn't say whether anyone died, but typically when the cops close down a road for investigation, that's the case. http://www.wfsb.com/story/24812944/route-85-closed-in-salem-following-crash For a few grand to clear some trees and level an embankment, we probably could've saved a life. 
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Feb 25, 2014 23:35
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Cichlidae posted:MUTCD sez: Whoa. I've never seen one in the US. Do you know of any?
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Feb 25, 2014 23:58
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PT6A posted:EDIT: Also, your picture link is broken, so I don't know what you're talking about. One thing I do like about Cuban traffic is the "via libre" at T-intersections. Basically, if the terminating road has a green light to turn left, but there are more lanes on the straight-through than there are lanes of traffic turning, then those extra lanes can proceed through on the red light. It threw me for a loop the first time I was in a taxi and I thought the taxi driver had just blown through a red light. They also have countdown timers for both red and green on most traffic lights, which I think is wonderful. Sorry for the broken link, the connection from here is not exactly reliable so imgur is playing tricks. http://imgur.com/7NtRWwO It was a picture of a countdown timer. They do count down on both red and green and they never seem to get pre-empted. Ambulances can't be going all that fast here anyway due to all the potholes... Hippie Hedgehog fucked around with this message at 00:35 on Feb 26, 2014 |
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Feb 26, 2014 00:24
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Hippie Hedgehog posted:Sorry for the broken link, the connection from here is not exactly reliable so imgur is playing tricks. It took a newly restored building in Habana Vieja getting gutted by fire before they realized it was a bad idea to block large areas off to all vehicle traffic (including fire engines), so I'm guessing they haven't really thought of all the negatives to something as small as not being able to pre-empt traffic lights. EDIT: I'm amazed you even tried to upload a photo on a Cuban internet connection. Realistically, even if it did work, it would probably take 1 CUC of internet time at the very least. Are you a visitor, foreign worker or resident, if you don't mind me asking? I don't see many posts coming from Cuba (that I know of) on these forums. PT6A fucked around with this message at 00:40 on Feb 26, 2014 |
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Feb 26, 2014 00:35
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SurgicalOntologist posted:Whoa. I've never seen one in the US. Do you know of any? I just drove through one the other day. I think it's basically because the other movements are so inconsequential (retail shops and a cemetery)  https://www.google.com/maps/dir/39.3126082,-76.5832101/39.3126093,-76.58315/@39.3126138,-76.5833361,118m/data=!3m1!1e3!4m4!4m3!1m0!1m0!3e2 Eastbound North Ave, turning right onto Milton
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Feb 26, 2014 00:43
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Lead out in cuffs posted:The ones in Vancouver are similar -- they're used at intersections of side streets with major roads, where the side street has no traffic light, only a stop sign (and pedestrian/cyclist buttons). During the green phase on the main street, the lights flash green to indicate that motorists should approach with care, and yield to traffic in the intersection if there is any. Motorists at side streets should only enter the intersection when it appears safe, but if they're in already, they have right of way. In Ontario a flashing green means that you have the right of way and nobody else is permitted to go ahead. It's mostly a legacy function on traffic signal heads that don't have a fourth bulb where only one side requires a protected left. Kind of an ironic opposite, really.
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Feb 26, 2014 03:10
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Solis posted:In Ontario a flashing green means that you have the right of way and nobody else is permitted to go ahead. It's mostly a legacy function on traffic signal heads that don't have a fourth bulb where only one side requires a protected left. Kind of an ironic opposite, really.
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Feb 26, 2014 04:24
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Cichlidae posted:In some rare cases, we've had electronic No Turn On Red signs that light up during the ped phase. Given that people usually ignore them anyway, I doubt compliance would be very high. Heck, even our RRFB is getting a thumbs down from drivers. I guess Connecticut is just a no man's land for pedestrians. Thanks for your answer. I think my path forward is going to be to try to change intersection standards as much as possible in the direction of slower vehicle speeds and shorter crossing distances, and then hope to re-engineer our worst intersections as IDOT money comes available out of the pittance they set aside for things that aren't 100% car-oriented 
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Feb 26, 2014 05:07
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Solis posted:In Ontario a flashing green means that you have the right of way and nobody else is permitted to go ahead. It's mostly a legacy function on traffic signal heads that don't have a fourth bulb where only one side requires a protected left. Kind of an ironic opposite, really. Yeah, Eastern Canada as a group seems to like this approach, and it freaks me right the hell out every time I see it. Give me a blinking arrow drat it.
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Feb 26, 2014 05:25
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Nice Davis posted:We're trying to get away from signals that require a trigger for a host of reasons, not the least of which is that someone shouldn't have to "ask permission" to make a crossing they're entitled to. Incidentally, our neighboring city just installed one of those at a mid-block crossing and it's bright as hell...you can see it a mile away. That said, RRFBs are turning out to be pretty mediocre as traffic control devices on higher ADT thoroughfares. Every one that's been installed in Tampa Bay has been an easily-ignored failure (almost no impact during daytime hours at Busch Blvd & 12th in Tampa). All proposed RRFB installs in Hillsborough Co have been upgraded to HAWK beacons, so that FHP/HCSO/TPD/TTPD/PCPD can issue tickets. 
Varance fucked around with this message at 06:57 on Feb 26, 2014 |
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Feb 26, 2014 06:39
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Varance posted:Jerkface Counterpoint: I have to ask permission for a green left turn arrow every time I pull up to a stop bar... and unless my vehicle sets off the loop detector, I don't get it. It doesn't have to be mandatory, just an optional device that can be used to add an extra layer of safety if needed (i.e., someone with a disability crossing the road). Since we're on the subject, something like Ontario's crosswalks. Is it that you have to ask for permission to turn left at all, or is it that you have to ask for permission to get an arrow that grants you a priority turning action? I'm unfamiliar with Canadian roads. e: At the signals I'm familiar with, triggering the loop triggers a priority turn. But if you don't trigger the loop, you still get to turn...you just have to wait instead of getting priority. pig slut lisa fucked around with this message at 07:00 on Feb 26, 2014 |
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Feb 26, 2014 06:57
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Nice Davis posted:Is it that you have to ask for permission to turn left at all, or is it that you have to ask for permission to get an arrow that grants you a priority turning action? I'm unfamiliar with Canadian roads. Nice Davis posted:e: At the signals I'm familiar with, triggering the loop triggers a priority turn. But if you don't trigger the loop, you still get to turn...you just have to wait instead of getting priority. I once sat at a traffic signal for three full phase rotations, all because the person in front of me was about 3 inches too far back. Tossed on my safety vest and walked up the median of a 69000 AADT road, knocked on the lady's window and asked her to pull up. She was playing Angry Birds and was perfectly content to sit at a traffic light for 10 minutes. 
Varance fucked around with this message at 07:11 on Feb 26, 2014 |
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Feb 26, 2014 07:01
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Varance posted:Talking about bog standard US intersections that are set to only give a green arrow when triggered. If you "forget" to trigger it (IE not covering the detector with your vehicle), you get nothing. I'm talking about some kind of enhanced pedestrian phase that only triggers when requested. Something as simple as a mounted RRFB calling attention to pedestrian action (activated by pushbutton or detected by camera), moving up to something complex like preventing all motions that would conflict with the crosswalk (we do this in Tampa around the University of South Florida and a few other high pedestrian accident locations). I see them as different situations. If you fail to trigger the arrow, all you lose is your priority turn. You still get a legal left turn. In contrast, if you don't trigger a pedestrian signal, then you lose more than priority...you lose your entire legal chance to cross. In my state, it's illegal to enter a crossing once the orange hand starts flashing (no matter how long it is til it goes solid). The difference is that cars failing to trigger get their turn bumped to the end of their part of the cycle, while walkers failing to trigger get their turn bumped to the entire next cycle.
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Feb 26, 2014 07:08
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Nice Davis posted:I see them as different situations. If you fail to trigger the arrow, all you lose is your priority turn. You still get a legal left turn. We expect our local roads to be able to handle 60000+ AADT. Every shortcut in the book is used to achieve that. Varance fucked around with this message at 19:26 on Feb 26, 2014 |
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Feb 26, 2014 07:14
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Varance posted:I'm talking about Florida's favorite style of fully-actuated signalling, set up so that a phase will be skipped until the next cycle if the detector isn't triggered. The new camera-based systems love making red light for 30 minutes in the rain. Well that sounds like a problem too. If requiring a trigger is a bad thing, I'm not sure that we should be aiming for making the driver and walker situations equally bad by accepting triggers for their respective signals. It seems instead like we should hope to make their situations equally good by eliminating triggers from both circumstances. Varance posted:We expect our local roads to be able to handle 60000+ AADT. Every shortcut in the book is used to achieve that. This is another justification for what we're trying to do in my community. Trying to maximize ADT is totally counterproductive to our goals. Saving drivers another 6.5 seconds at a particular intersection is not in the top 100 on our list of priorities. pig slut lisa fucked around with this message at 07:23 on Feb 26, 2014 |
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Feb 26, 2014 07:19
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Nice Davis posted:Well that sounds like a problem too. If requiring a trigger is a bad thing, I'm not sure that we should be aiming for making the driver and walker situations equally bad by accepting triggers for their respective signals. It seems instead like we should hope to make their situations equally good by eliminating triggers from both circumstances. It currently takes 6 minutes for a 4-lane cross street to get a green light along US92/Hillsborough Ave in Tampa. On a Sunday. Please, please, please don't be like us. 
Varance fucked around with this message at 07:37 on Feb 26, 2014 |
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Feb 26, 2014 07:23
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Varance posted:Our problem is that everything has been NIMBYed for 50 years. Everything. We've got signalized 10-lane arterial roads pulling 70-80k AADT because every expressway and higher-order transit proposal has been shot down by residents looking to have the lowest taxes possible. That's a really, really, really big problem, as you can't afford to give a protected phase to an empty lane at those volumes. That sounds like the kind of problem that traffic engineering is totally unqualified to fix, to be honest. Squeeze out a little more traffic flow efficiency at that intersection, and now all of a sudden you've lowered the time costs of travelling that route. A little induced traffic later and you're right back where you started from, only deeper in the hole financially thanks to increased construction and maintenance costs. It sounds like you think planning and politics are the problem in that part of town. And judging by your summary, I'd agree with that! But it's important to separate those things from traffic engineering. Engineering that terrible intersection to move traffic more efficiently isn't going to improve the situation; it's only going to exacerbate the features that already make it terrible.
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Feb 26, 2014 07:35
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Solis posted:In Ontario a flashing green means that you have the right of way and nobody else is permitted to go ahead. It's mostly a legacy function on traffic signal heads that don't have a fourth bulb where only one side requires a protected left. Kind of an ironic opposite, really. So basically like a blinking arrow in Western Canada (i.e. a protected left turn) combined with the ability to go straight through? That's what a green blinking light meant in Montreal, but I thought that was a Quebec peculiarity. EDIT: Speaking of Quebec peculiarities: they don't allow right turns on red in urban areas. What's the conventional wisdom on this according to traffic engineers? On one hand, I like being able to turn right on red, but I have to imagine it's more dangerous and I would trade it for a second for a green light where pedestrians don't get a walk sign for a few seconds. PT6A fucked around with this message at 07:40 on Feb 26, 2014 |
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Feb 26, 2014 07:37
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Nice Davis posted:It sounds like you think planning and politics are the problem in that part of town. And judging by your summary, I'd agree with that! But it's important to separate those things from traffic engineering. Engineering that terrible intersection to move traffic more efficiently isn't going to improve the situation; it's only going to exacerbate the features that already make it terrible. When the cost of fixing the problem is tens of billion of dollars, yes. With so many problem areas, where do you begin? And who will let you tear down their houses and businesses to fix it? Not in my backyard. Put more buses on the road? No, that's poor people transit. Rail transit? It doesn't have a stop in front of my house, voting no.   Orlando has similar problems, but they at least built a beltway and a few other expressways, plus they have light and commuter rail on the way. Tampa hasn't done any of that, and now has arguably the worst traffic in the country. Varance fucked around with this message at 07:56 on Feb 26, 2014 |
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Feb 26, 2014 07:49
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Varance posted:When the cost of fixing the problem is tens of billion of dollars, yes. With so many problem areas, where do you begin? And who will let you tear down their houses and businesses to fix it? Sadly there isn't a good solution outside of engaging in party politics and shifting the Overton window. If a transit department director does the responsible thing and adopts a long-term view where they create a good master plan, refuse to accept any temporary solutions, and wait for the public to get so sick of slow traffic that they pony up money for basic infrastructure, then the public will probably just fire the director and appoint someone who is willing to throw money at a quick fix. Kaal fucked around with this message at 07:55 on Feb 26, 2014 |
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Feb 26, 2014 07:53
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