http://www.athensreview.com/local/x1146349285/Driver-sits-in-front-of-street-light-too-long
QuoteThe man was able to post both bonds, and he was released from Henderson County Jail on Monday, possibly to sit in front of the same stop light on his way home.
Speaking of signals going on too long, twice in my life I have been subjected to 30-second yellow lights. The first was in Manhattan, 9th Ave. SB at 59th St., and after about 10 seconds all the cars started going through. It did eventually change as we looked behind us, but clearly was not well. The second was in Boston, SB on the Surface Artery during the Big Dig. That one, not sure if it ever actually did change.
Years ago, I remember the traffic signal on NJ 34 at the Earle Navy Complex in Colt's Neck, the signal was stuck on yellow for NJ 34. It did not seem to change as I kept looking back until it was out of view.
^^ Reminds me of The Simpsons MENSA episode where they changed all the traffic lights to be yellow and red to improve traffic flow. "C'mon.... stay yellow, stay yellow.... Wow, I'm making record time...if only i had someplace to be." - Lenny
The article doesn't mention what the actual timing of that light is so it's hard to determine if it's indeed too long. Now Clinton Rd. and NJ 23, that's a long light at 5.5 minutes. (http://www.nytimes.com/2001/06/24/nyregion/on-the-road-the-longest-light.html)
But while we're telling off-topic stories of getting stuck at long yellow lights, I was on a group bicycle ride coming from Rutgers' College Ave. Campus and this happened to me. As we were on College Ave. and the light at the Huntingdon St. intersection turned green, it turned green for a like two seconds and then turned yellow. About half of the group went through while they had the green and the back half (of which I was a part) waited at the light. That yellow was on for at least seven seconds so we all decided to screw it and went through anyway. I know I've seen that happen at that light another time and there was one instance where I saw both a red and a green illuminated on a signal head at one time. Luckily the other heads were working so I didn't have to worry too much.
I've seen signals briefly display both yellow and red at the same time before (plus one extended period of time that I've still yet to figure out what I was supposed to have done at).
I ran a signal in Boston on the Jamaicaway (at Brookline Ave I believe) last weekend after it remained red for several minutes. Most traffic was just running it, barely slowing down, as if there were no signal at all, so I don't know if it is always like that or what, but the signals on the cross street stayed green, even changing for protected left turns, but never cycling through green on the Jamaicaway. Eventually I decided to just run it like everyone else.
Quote from: deathtopumpkins on July 22, 2012, 09:51:06 PM
I've seen signals briefly display both yellow and red at the same time before (plus one extended period of time that I've still yet to figure out what I was supposed to have done at).
That's an all-pedestrian 'Barnes dance' phase.
Quote from: deathtopumpkins on July 22, 2012, 09:51:06 PM
I've seen signals briefly display both yellow and red at the same time before (plus one extended period of time that I've still yet to figure out what I was supposed to have done at).
Was this display in the US? I've heard of such instances used in various locations around Europe. The extra yellow display was cue to standard transmission drivers to prepare to get their cars into the proper gear for the impending light change.
"Maurice Rached, a project engineer with the state Department of Transportation in Bergen, Passaic and Essex Counties, said that drivers trying to cross Route 3 in Bergen and Passaic counties and Routes 1 and 9 in Essex County had similar problems."
Both of those roads have no traffic lights. So I totally don't get her statement.
Quote from: DaBigE on July 22, 2012, 10:57:30 PM
Quote from: deathtopumpkins on July 22, 2012, 09:51:06 PM
I've seen signals briefly display both yellow and red at the same time before (plus one extended period of time that I've still yet to figure out what I was supposed to have done at).
Was this display in the US? I've heard of such instances used in various locations around Europe. The extra yellow display was cue to standard transmission drivers to prepare to get their cars into the proper gear for the impending light change.
Yes, the light will show red and yellow simultaneously for a second or two before it turns green. It's that way in Germany for sure, but I don't remember if it is in France and Britain.
Here, I just look at the side street lights to turn yellow and see if anyone is in the left turn lane coming toward me.
I've seen the combined red-yellow cycle in at least the UK, Germany, and Russia.
I love it and I wish our lights did the same thing. It's damn annoying the way you don't get any notice that the light's going green. You can do as "Road Hog" suggests about watching the other street, but that doesn't always work for a variety of reasons, and the odds are the doofus in front of you playing with a mobile phone isn't watching the other light.
Of course, they don't have the same problem with red-light running that parts of the US do, either. In the UK when the red-yellow cycle comes on everyone shifts into gear and is essentially starting to move right as the light goes green. In the US if you move that quickly you stand a real chance of getting broadsided.
It was somewhere here in Mass I believe... Salem maybe... not one of the flashing green ped signals though.
I've sat at a red light for about 5 minutes before. I was trying to make a left from a minor side street onto a major arterial, at about 1am.
figuring that I simply had not triggered the change, I backed up and moved forward again. nothing. so I looked both ways and ran the red.
Quote from: Road Hog on July 23, 2012, 05:55:07 AM
Quote from: DaBigE on July 22, 2012, 10:57:30 PM
Quote from: deathtopumpkins on July 22, 2012, 09:51:06 PM
I've seen signals briefly display both yellow and red at the same time before (plus one extended period of time that I've still yet to figure out what I was supposed to have done at).
Was this display in the US? I've heard of such instances used in various locations around Europe. The extra yellow display was cue to standard transmission drivers to prepare to get their cars into the proper gear for the impending light change.
Yes, the light will show red and yellow simultaneously for a second or two before it turns green. It's that way in Germany for sure, but I don't remember if it is in France and Britain.
Finland shows a yellow under red for a short time before green, especially for protected-phase left turns.
Quote from: deathtopumpkins on July 22, 2012, 09:51:06 PM
I've seen signals briefly display both yellow and red at the same time before (plus one extended period of time that I've still yet to figure out what I was supposed to have done at).
Unless it's an old pedestrian-activated signal (many MA towns still use this); that just simply means that the signal is malfunctioning. I've seen yellow & green lit at the same time as well for the latter condition.
Quote from: agentsteel53 on July 23, 2012, 11:48:07 AM
I've sat at a red light for about 5 minutes before. I was trying to make a left from a minor side street onto a major arterial, at about 1am.
figuring that I simply had not triggered the change, I backed up and moved forward again. nothing. so I looked both ways and ran the red.
In that instance, if you get stopped, I'd think a malfunctioning light would be a valid defense.
Quote from: Road Hog on July 23, 2012, 02:34:24 PM
In that instance, if you get stopped, I'd think a malfunctioning light would be a valid defense.
probably - though I could have turned right and made a U-turn later. but I had judged that there was no one coming (there was maybe 1 car per minute, which I could see from far away in each direction) so what I was doing was safe.
no idea how well that would've held up in court, but as no one saw me ...
Quote from: agentsteel53 on July 23, 2012, 11:48:07 AM
I've sat at a red light for about 5 minutes before. I was trying to make a left from a minor side street onto a major arterial, at about 1am.
figuring that I simply had not triggered the change, I backed up and moved forward again. nothing. so I looked both ways and ran the red.
I've done the exact same thing, but on a straight-thru movement.
Same here. But it was on a bike so I'm a dirty scofflaw.
Quote from: NE2 on July 24, 2012, 01:10:24 AM
Same here. But it was on a bike so I'm a dirty scofflaw.
yup totally
This brings up an interesting question. Do any states have a specific time limit after which a motorist is legally allowed to assume a signal is malfunctioning and disobey it?
Quote from: deathtopumpkins on July 24, 2012, 01:03:14 PM
This brings up an interesting question. Do any states have a specific time limit after which a motorist is legally allowed to assume a signal is malfunctioning and disobey it?
It's not exactly the same case, but Wisconsin makes an allowance for 2-wheeled vehicles:
Quote from: Wisconsin SS §346.37(1)(c)4Notwithstanding subd. 1., a motorcycle, moped, motor bicycle, or bicycle facing a red signal at an intersection may, after stopping as required under subd. 1. for not less than 45 seconds, proceed cautiously through the intersection before the signal turns green if no other vehicles are present at the intersection to actuate the signal and the operator of the motorcycle, moped, motor bicycle, or bicycle reasonably believes the signal is vehicle actuated. The operator of a motorcycle, moped, motor bicycle, or bicycle proceeding through a red signal under this subdivision shall yield the right-of-way to any vehicular traffic, pedestrian, bicyclist, or rider of an electric personal assistive mobility device proceeding through a green signal at the intersection or lawfully within a crosswalk or using the intersection. This subdivision does not affect any authorization for a bicyclist under subd. 2.
Other than that, I can't seem to find anything related to a malfunctioning signal in our statutes. One would hope to assume common sense would prevail, Read: Check for conflicting traffic and go when the way is clear.
Quote from: deathtopumpkins on July 23, 2012, 11:16:54 AM
It was somewhere here in Mass I believe... Salem maybe... not one of the flashing green ped signals though.
Until the 1971 MUTCD outlawed it, it was standard practice in Massachusetts (and other New England states as well) to display red and yellow to indicate an exclusive pedestrian phase. I beleive there's still a handful of signals in Massachusetts that haven't yet been replaced or updated that still show red and yellow for pedestrians.
A standard red-yellow pedestrian phase: http://www.youtube.com/watch?v=DDYL2LW_FEg
I encountered a stuck signal in The Bronx once. East Tremont Ave and some minor side street (I forget exactly which, it was between The Hutch and The Bruckner). The next light down the road cycled through twice, mine didn't change. So, I waited for an opening and made the left turn I had intended to make anyway through the red light. It should be noted that right on red is illegal in New York City, so that could not have been taken advantage of here.
Even more weird, though, I've encountered a couple of signals where both the red and green were lit simultaneously. One at a school driveway which was closed to vehicles because graduation ceremony was in progress. Due to heavy pedestrian and vehicle traffic, there was a cop in the intersection directing people. I assume the light was intentionally deactivated for this and through some programming oddity it ended up like that rather than dark or flashing.
The other was a case where the signal was operating normally, but one signal head facing each way had the red light seemingly stuck on. So traffic coming up or down the road would encounter two red lights when the light was red, but a red light and two green lights when the light was green. Drove passed it three times that day with it in the same condition, but didn't see if it was also happening to the side street. This was during and after a nasty storm, and it was fine when I drove past it earlier that day before the storm, so I assume lightning was involved.
speaking of light deactivations ... I was at an event downtown last weekend with some streets closed off, and some of the traffic lights were going on their normal cycle, while others were flashing all-red.
it was a moot point, because the streets were barricaded off, with police located strategically.
Florida has one in Orlando near the Florida Mall. Orange Blossom Trail and LaQuinta Drive when a SB vehicle on OBT turns left onto EB LaQuinta it does not give the through green movement on NB OBT. What it does is turns green again on LaQuinta Drive. So you have the light turn green twice during your one time red stop only if another car does not make a left again SB to EB.
Plus the signal is defaulting to timer on LaQuinta cause the detector hoops are not working. It ends up you could wait a few minuets to travel there when this happens. Of course, this was happening months ago and just happened again last week. Maybe it was never fixed because no one bothered to report the signal to Orange County who operates the light. Being it took months for people in my subdivision to make a complaint that the signal outside our development was timed wrong, I can believe that. For almost two years people were waiting two minuets or more to exit the housing area on to our main street during the 5 AM hour, and no one thought to pick up the phone and call until earlier this year.
Quote from: DaBigE on July 24, 2012, 01:34:09 PM
Quote from: deathtopumpkins on July 24, 2012, 01:03:14 PM
This brings up an interesting question. Do any states have a specific time limit after which a motorist is legally allowed to assume a signal is malfunctioning and disobey it?
It's not exactly the same case, but Wisconsin makes an allowance for 2-wheeled vehicles:
Quote from: Wisconsin SS §346.37(1)(c)4Notwithstanding subd. 1., a motorcycle, moped, motor bicycle, or bicycle facing a red signal at an intersection may, after stopping as required under subd. 1. for not less than 45 seconds, proceed cautiously through the intersection before the signal turns green if no other vehicles are present at the intersection to actuate the signal and the operator of the motorcycle, moped, motor bicycle, or bicycle reasonably believes the signal is vehicle actuated. The operator of a motorcycle, moped, motor bicycle, or bicycle proceeding through a red signal under this subdivision shall yield the right-of-way to any vehicular traffic, pedestrian, bicyclist, or rider of an electric personal assistive mobility device proceeding through a green signal at the intersection or lawfully within a crosswalk or using the intersection. This subdivision does not affect any authorization for a bicyclist under subd. 2.
Other than that, I can't seem to find anything related to a malfunctioning signal in our statutes. One would hope to assume common sense would prevail, Read: Check for conflicting traffic and go when the way is clear.
This is common - I remember Virginia passed such a law a few years before I moved.
One would assume that common sense would prevail, yes, but one should know otherwise. ;-)
Quote from: deathtopumpkins
Quote from: DaBigE on July 24, 2012, 01:34:09 PM
It's not exactly the same case, but Wisconsin makes an allowance for 2-wheeled vehicles:
Quote from: Wisconsin SS §346.37(1)(c)4Notwithstanding subd. 1., a motorcycle, moped, motor bicycle, or bicycle facing a red signal at an intersection may, after stopping as required under subd. 1. for not less than 45 seconds, proceed cautiously through the intersection before the signal turns green if no other vehicles are present at the intersection to actuate the signal and the operator of the motorcycle, moped, motor bicycle, or bicycle reasonably believes the signal is vehicle actuated. The operator of a motorcycle, moped, motor bicycle, or bicycle proceeding through a red signal under this subdivision shall yield the right-of-way to any vehicular traffic, pedestrian, bicyclist, or rider of an electric personal assistive mobility device proceeding through a green signal at the intersection or lawfully within a crosswalk or using the intersection. This subdivision does not affect any authorization for a bicyclist under subd. 2.
This is common - I remember Virginia passed such a law a few years before I moved.
Good to know... after the fact. I had a situation (in VA) last week in a left-turn lane with a left-turn signal. I knew my bicycle would not activate it, so I just turned left when there was no oncoming traffic (and cross-traffic still had a red). I wasn't sure if there was a law/regulation dealing with that, but wasn't going to wait for someone else to turn left behind me.
Fixed your quote - DTP
The RYG in a certain part of Aiken County is downright awful. At CHARLESTON HY's (US 78's) westernmost terminus stays red for about two minutes before it changes. That absolutely snarls up traffic on EAST PINE LOG RD & RUDY MASON PKWY (SC 118/302) at their shared intersection with WAGENER RD (SC 4/302).
No wonder why so many people who are short on time go to WILLISTON RD (US 278) and then turn right in New Ellenton on SOUTH WHISKEY RD (SC 19) to go to Aiken.
After a minute. No car, no cop, no stop.
I believe it's actually legal for motorcycles to run reds in some states if they've waited at an empty light for more than a minute. The coil detectors don't always pick up motorcycles, and the IR detector is relatively new (and doesn't work well in weather).
Most signals, if designed by a decent engineer, should have 20 second timer to change if it doesn't recognize any vehicles.
Quote from: KEK Inc. on August 05, 2012, 04:36:15 PM
Most signals, if designed by a decent engineer, should have 20 second timer to change if it doesn't recognize any vehicles.
Wait, what? You're saying the signal should change if there's no detection? The whole idea behind full actuation is the ability to skip unused phases and "rest in green" if uncalled.
I think he's talking about having loops on both roads and having the signal change every so often anyway if it detects no vehicles in either place.
Don't think that's typical, though. Usually there are no loops on the main road.
What you do want to do, however, is set it up so that if one of the loops breaks, it constantly triggers rather than going dead. Better to have a phase every cycle than to eternally skip it.
Quote from: Duke87 on August 06, 2012, 09:14:51 PM
I think he's talking about having loops on both roads and having the signal change every so often anyway if it detects no vehicles in either place.
Don't think that's typical, though. Usually there are no loops on the main road.
What you do want to do, however, is set it up so that if one of the loops breaks, it constantly triggers rather than going dead. Better to have a phase every cycle than to eternally skip it.
Yes, and that is good traffic engineering, absolutely. But still, proper engineering for actuation when circuits are working is to rest in one phase, not cycle through. (Fixed timing doesn't get much use anymore - I'd say mainly if you're talking about a circuit of urban signals with central management.)
Few traffic signals use loops embedded in the road anymore. The ones in Texas use optic motion sensors mounted on the crossbar the last 10 years. A lot cheaper to replace when they malfunction. Doesn't reduce the rate of malfunction, unfortunately.
Quote from: Road Hog on August 07, 2012, 06:36:30 AM
Few traffic signals use loops embedded in the road anymore. The ones in Texas use optic motion sensors mounted on the crossbar the last 10 years. A lot cheaper to replace when they malfunction. Doesn't reduce the rate of malfunction, unfortunately.
Huh? Most traffic signals around here use loops, even the new ones.
loops here in CA as well.
but that's because no new roads have been built in the last 10 years. :pan:
More jurisdictions are switching to video, but loops are still cheaper. Loops make more sense in warm areas like California or the South and Southwest, because it's the freeze/thaw cycles that buckle the pavement and break the loops. Without that, a loop will easily last for the life of the pavement, and then you just have to replace the loop every N years. All in all, as much as we like to see new, better technology be employed, cost is the 40,000 lb gorilla.
The loop is the tried and true method for vehicle detection. Loops are cheap, simple, and effective and outperform more expensive technologies like video detection, radar, wireless pucks etc.. This is a fact that a lot of jurisdictions don't want to admit because they've been suckered into investing in some advanced vehicle detection technology that doesn't work very well.
Quote from: tradephoric on August 07, 2012, 08:25:59 PM
The loop is the tried and true method for vehicle detection. Loops are cheap, simple, and effective and outperform more expensive technologies like video detection, radar, wireless pucks etc.. This is a fact that a lot of jurisdictions don't want to admit because they've been suckered into investing in some advanced vehicle detection technology that doesn't work very well.
Tried and true isn't always best. I have looked a lot more than you have into these technologies - I can tell by the way you've phrased this - as part of my work. As I said, each one has its own application. You have to look at all of the circumstances, particularly weather cycles and types of vehicles, to select the appropriate technology. Loops do not "outperform." Don't spread misinformation.
Quote from: Steve on August 08, 2012, 08:16:02 PM
Tried and true isn't always best. I have looked a lot more than you have into these technologies - I can tell by the way you've phrased this - as part of my work. As I said, each one has its own application. You have to look at all of the circumstances, particularly weather cycles and types of vehicles, to select the appropriate technology. Loops do not "outperform." Don't spread misinformation.
You've got me curious now. What might be some scenarios where video detection might be a better option than loops? I've noticed a handful of camera-controlled intersections here in the Columbus area but the vast majority have loops, so I'm wondering what's different about the intersections that get video.
Quote from: Central Avenue on August 08, 2012, 08:30:53 PM
Quote from: Steve on August 08, 2012, 08:16:02 PM
Tried and true isn't always best. I have looked a lot more than you have into these technologies - I can tell by the way you've phrased this - as part of my work. As I said, each one has its own application. You have to look at all of the circumstances, particularly weather cycles and types of vehicles, to select the appropriate technology. Loops do not "outperform." Don't spread misinformation.
You've got me curious now. What might be some scenarios where video detection might be a better option than loops? I've noticed a handful of camera-controlled intersections here in the Columbus area but the vast majority have loops, so I'm wondering what's different about the intersections that get video.
Check my post upstream. Weather can fatigue loops and require them to be replaced every year. Heavy truck traffic, same issue. NJDOT got tired of having to constantly send crews out and maintain loops, so they've gone camera for everything. (That's not necessarily the right approach, but I'm sure they did the math, because they don't have the money to waste.)
Additionally, loops can't detect plastic bikes. Obviously a huge concern.
Quote from: NE2 on August 08, 2012, 09:12:10 PM
Additionally, loops can't detect plastic bikes. Obviously a huge concern.
Loops can't detect bicycles in general - too small a magnetic footprint - unless they're tuned to be so sensitive that they pick up other magnetic noise as well. The problem is that loops don't even pick up motorcycles.
One other reason that loops are sometimes not favored - concrete pavement. DOTs don't like to go digging - it's expensive and messes with structural integrity.
Let's focus on the effectiveness of video detection. A 1992 study by MacCarley compared the performance of eight video detection systems and found that detection was inaccurate during transitional lighting periods. A 2009 study entitled "Evaluation of Video Detection Systems Volume 2 — Effects of Illumination Conditions in the Performance of Video Detection Systems" came up with the following conclusions (the cameras used included Autoscope, Iteris, and Peek)
QuoteDuring sunny morning, false calls increased in greater proportion in zones where vehicle shadows were more prominent (up to 21% at stop bar and up to 43% at advance zones). Results during the dusk condition followed trends similar to the dawn, but with higher increases in false calls (ranging from no change to about 50% increase); and higher increases in the missed calls observed for one VDS.
After 20 years of research the same problems persist; in this case highly inaccurate counts during transitional lighting conditions. A 50% false call rate can have crippling effects on an adaptive signals system. Keep in mind 99% of all traffic signals are basically non-adaptive. A high false call rate won't have much effect on the operations of a signal that runs a preset timing with limited adaptive operations (ie. simple side-streets gapping or skipping phases). Basically the shortcomings of any technology can be masked when it isn't being used to its full potential (don't need the security system in your house to work if you never get robbed).
Adaptive signal systems (SCOOTS, SCATS, INSYNC, RHODES ) are the future when it comes to providing efficient signal operations but these systems require accurate counts or they can create more problems than they solve. A camera that is over-counting (bright sunny morning) can soak up the green time from the main-street even though there may be little or no traffic on the side-street. Similarly, it's not uncommon for a camera to provide multiple cycles of zero counts (bad filter or Autoscope unit in the cabinet) and may cause the main-street to vote for a minimum green time. It doesn't look pretty when a major 6-lane boulevard is voting for 10 second greens because the main-street camera isn't picking up any counts for multiple cycles. When you manage a signal system of 600 signals, half with video detection and half with loops, and the major problems described above only occur at the intersections with cameras it becomes a no-brainer which detection system to choose.
Here's one last finding from a study Perdue did in 2006 that may be impractical for most agencies to adhere to and lead to serious pause when considering the use of video detection. Intersection with loops can chug along for 10 years with the crew barely opening the cabinet:
Quote
The accuracy of all three systems appears to degrade with time and it appeared that a re-calibration was necessary only 4 months after the initial installation by factory representatives.
The misinformation often comes from the mouths of aggressive vendors trying to sell a product. The fact remains that the studies have shown the same problems that were around with video detection in 1992 are still around today. Loops outperform video detection when it comes to false calls, missed calls, stuck-on calls, or dropped calls at an intersection.
Quote from: DaBigE on July 24, 2012, 01:34:09 PM
Quote from: deathtopumpkins on July 24, 2012, 01:03:14 PM
This brings up an interesting question. Do any states have a specific time limit after which a motorist is legally allowed to assume a signal is malfunctioning and disobey it?
It's not exactly the same case, but Wisconsin makes an allowance for 2-wheeled vehicles:
Quote from: Wisconsin SS §346.37(1)(c)4Notwithstanding subd. 1., a motorcycle, moped, motor bicycle, or bicycle facing a red signal at an intersection may, after stopping as required under subd. 1. for not less than 45 seconds, proceed cautiously through the intersection before the signal turns green if no other vehicles are present at the intersection to actuate the signal and the operator of the motorcycle, moped, motor bicycle, or bicycle reasonably believes the signal is vehicle actuated. The operator of a motorcycle, moped, motor bicycle, or bicycle proceeding through a red signal under this subdivision shall yield the right-of-way to any vehicular traffic, pedestrian, bicyclist, or rider of an electric personal assistive mobility device proceeding through a green signal at the intersection or lawfully within a crosswalk or using the intersection. This subdivision does not affect any authorization for a bicyclist under subd. 2.
Other than that, I can't seem to find anything related to a malfunctioning signal in our statutes. One would hope to assume common sense would prevail, Read: Check for conflicting traffic and go when the way is clear.
I recall a discussion on that several years ago and from what I gathered, that Wisconsin law applied to all motor vehicles.
I wonder if it was changed at some point.
Mike
QuoteWeather can fatigue loops and require them to be replaced every year. Heavy truck traffic, same issue.
To suggest loops will only last a year in states that experience cycles of frost heave or states with high weight limits on trucks is highly inaccurate. Loops can easily last 15 years with little maintenance (replacing a loop rack, etc). even in harsh weather states.
QuoteNJDOT got tired of having to constantly send crews out and maintain loops, so they've gone camera for everything. (That's not necessarily the right approach, but I'm sure they did the math, because they don't have the money to waste.)
You've never heard the phrase "wasteful government spending" before?
Tradephoric, can you come out and say which company you work for that manufactures loops? Because this is getting very tiresome. For the record, it's better to have false calls - which video systems are designed with intentionally - than to miss calls, which loops have been known to do (broken connection, for example). Better to have the side street turn green too much than never.
QuoteFor the record, it's better to have false calls - which video systems are designed with intentionally - than to miss calls, which loops have been known to do (broken connection, for example).
That's inaccurate. A detector unit provides a continuous call in the controller if the loop circuit is incomplete (broken connection).
There's undoubtedly problems with both loops and video. I may have been a bit harsh with video detection in my initial post but I'm not the only guy who has seen the problems that exist with video detection. This is an abstract that was written by the Texas Transportation Institute:
QuoteDue to the well-documented problems associated with inductive loops, most jurisdictions have replaced many intersection loops with video image vehicle detection systems (VIVDS). While VIVDS have overcome some of the problems with loops such as traffic disruption and pavement degradation, they have not been as accurate as originally anticipated. The object of this project is to conduct evaluations of alternative detector technologies for application into the state's traffic signal systems. The research will include investigating the available detectors that could replace loops or VIVDS through a literature search and agency contacts, followed by field and/or laboratory investigations of promising technologies. (FHWA/TX-09/0-5845-1)
Video detection has always had potential but has never been able to achieve the accuracy needed for most agencies to be a viable long-term solution.
Well I've witnessed loops miss calls, so take that for what it's worth. Also, TTI is a lot more reasonable than you are about other technologies. In particular, you gloss over "well documented problems with inductive loops." Kinda sinks your feeble ship there, donnit?
Below is the listed weaknesses of inductive loops according to the FHWA Traffic Control Systems Handbook:
-Installation requires pavement cut.
-Improper installation decreases pavement life.
-Installation and maintenance require lane closure.
-Wire loops subject to stresses of traffic and temperature.
-Multiple detectors usually required to monitor a location.
-Detection accuracy may decrease when design requires detection of a large variety of vehicle classes.
It's clear when you read my posts that the accuracy of vehicle detection systems is of critical importance. Video detection that outputs 50% false calls in transitional light conditions, prolonged cycles of zero counts, and missed calls in low-light conditions is unacceptable performance. Based on the studies, TTI's findings, and personal experience video detection is not the most accurate. I welcome differing points of view but they are most effective when they are backed by facts.
Is it really that troublesome to have traffic signals that cycle every time, even if it is only for two seconds for the minor street? As a bicyclist, there are plenty of intersections that are "hit or miss" regarding detection.
Quote from: tradephoric on August 14, 2012, 11:24:40 PM
Below is the listed weaknesses of inductive loops according to the FHWA Traffic Control Systems Handbook:
-Installation requires pavement cut.
-Improper installation decreases pavement life.
-Installation and maintenance require lane closure.
-Wire loops subject to stresses of traffic and temperature.
-Multiple detectors usually required to monitor a location.
-Detection accuracy may decrease when design requires detection of a large variety of vehicle classes.
It's clear when you read my posts that the accuracy of vehicle detection systems is of critical importance. Video detection that outputs 50% false calls in transitional light conditions, prolonged cycles of zero counts, and missed calls in low-light conditions is unacceptable performance. Based on the studies, TTI's findings, and personal experience video detection is not the most accurate. I welcome differing points of view but they are most effective when they are backed by facts.
As a moderator, I will ask you for the last time why you are so pro-loop and anti-video. Do you work for someone in the industry or is this just your strong opinion?
I'm pro-vehicle detection that is accurate and inductive loops are more accurate than video detection.
QuoteTradephoric, can you come out and say which company you work for that manufactures loops?
It's not appreciated that a moderator on this forum would be making baseless accusations.
Quote from: tradephoric on August 15, 2012, 07:56:31 AM
I'm pro-vehicle detection that is accurate and inductive loops are more accurate than video detection.
QuoteTradephoric, can you come out and say which company you work for that manufactures loops?
It's not appreciated that a moderator on this forum would be making baseless accusations.
Well look around the forum, most people aren't as vehement as you are on such a picayune topic.
Quote from: Steve on August 15, 2012, 08:22:59 AM
Well look around the forum, most people aren't as vehement as you are on such a picayune topic.
wtf? we've never seen a strong opinion before?
I don't like traffic lights on freeway-to-freeway connections, preferring instead long flyover ramps, so I must be working for a concrete company.
Quote from: Steve on August 08, 2012, 08:35:02 PM
(That's not necessarily the right approach, but I'm sure they did the math, because they don't have the money to waste.)
they don't? you mean flying the governor around in a helicopter was a judiciously considered reaction based on fiscal prudence?
Quote from: agentsteel53 on August 15, 2012, 12:25:59 PM
Quote from: Steve on August 08, 2012, 08:35:02 PM
(That's not necessarily the right approach, but I'm sure they did the math, because they don't have the money to waste.)
they don't? you mean flying the governor around in a helicopter was a judiciously considered reaction based on fiscal prudence?
The NJDOT did not do that.
Quote from: tradephoric on August 14, 2012, 11:24:40 PM
-Installation requires pavement cut.
-Improper installation decreases pavement life.
-Installation and maintenance require lane closure.
-Wire loops subject to stresses of traffic and temperature.
-Multiple detectors usually required to monitor a location.
-Detection accuracy may decrease when design requires detection of a large variety of vehicle classes.
-The loops can be damaged by brine that can seep in as a result of winter maintenance
-If there is a lot of traffic with heavy axle loadings (laden trucks and two-axle six tire transit buses) and the pavement is flexible (asphalt), then pavement can get rutted, which can damage the loops.
Quote from: agentsteel53 on August 15, 2012, 12:23:20 PM
Quote from: Steve on August 15, 2012, 08:22:59 AM
Well look around the forum, most people aren't as vehement as you are on such a picayune topic.
wtf? we've never seen a strong opinion before?
I don't like traffic lights on freeway-to-freeway connections, preferring instead long flyover ramps, so I must be working for a concrete company.
Better yet: all the folks on here who are vehement about hydraulic concrete being better than asphalt must work for the cement companies.
Quote from: kphoger on August 16, 2012, 01:30:31 PM
Quote from: agentsteel53 on August 15, 2012, 12:23:20 PM
Quote from: Steve on August 15, 2012, 08:22:59 AM
Well look around the forum, most people aren't as vehement as you are on such a picayune topic.
wtf? we've never seen a strong opinion before?
I don't like traffic lights on freeway-to-freeway connections, preferring instead long flyover ramps, so I must be working for a concrete company.
Better yet: all the folks on here who are vehement about hydraulic concrete being better than asphalt must work for the cement companies.
I've never seen someone here argue that concrete is best in every application.
Those who argue against bikes on the road work for the car companies.
I looked and looked and I could not find a single Texas statute that covered what one should do at a malfunctioning red light. I did find lots of discussion about it, however.
I guess you're either supposed to turn right on red and then do a U-turn, or just patiently sit and wait for TxDOT to get off its duff and fix it. Or just damn the torpedoes and hope if there is a cop, he or she is reasonable.
Quote from: NE2 on August 16, 2012, 10:36:05 PM
Those who argue against bikes on the road work for the car companies.
No, we're just the type of people who think of driving as fun rather than a chore.
And we don't object to bikes being on the road... we object to bikes being given a higher priority on the road than us and being inconvieienced (however that word's spelled... chrome's spell check is no help here) by them.