Forum Settings
       
Reply To Thread

Driving habitsFollow

#52 Aug 19 2014 at 1:00 PM Rating: Good
******
27,272 posts
Elinda wrote:
Rotaries and/or traffic circles. Everyone goes. No one stops. No light. No sound.

Nothing under the ground to maintain.
Wonderful in theory but they really don't always work, especially with heavy traffic. And then there's the double lane roundabouts that are just confusing as **** for everyone.
#53 Aug 19 2014 at 1:04 PM Rating: Good
*******
50,767 posts
Â
____________________________
George Carlin wrote:
I think it’s the duty of the comedian to find out where the line is drawn and cross it deliberately.
#54 Aug 19 2014 at 1:08 PM Rating: Good
Skelly Poker Since 2008
*****
16,781 posts
His Excellency Aethien wrote:
[quote=Elinda] And then there's the double lane roundabouts that are just confusing as **** for everyone.

They're really not. One of our main intersections here in our state capital city is a rotary - 3 lanes. It keeps traffic moving. Also it's very intimidating for people from away. It's no Arc de Triomphe, but during the holidays it's filled up with lighted x-mas trees. I like it.

____________________________
Alma wrote:
I lost my post
#55 Aug 19 2014 at 2:21 PM Rating: Decent
Encyclopedia
******
35,568 posts
Sir Xsarus wrote:
Generally car detection is on the stopped end to determine if there is a need to change the light, not on the moving cars. What are you basing this off of, speculation?


Observation. You've honestly never noticed this? I suppose it's possible that you've never lived in an area that uses loop sensors like this, but where I live nearly every light is equipped with them and it's incredibly obvious (if you pay attention) how the behavior works. In a quaint small town where a car rolling up to a light is a rare event, you could just use the sensors to trigger a change in the direction the car has arrived at. But in areas where there is constant traffic, this doesn't work (cause there's *always* a car on the cross traffic sensor). You have to have a method to determine if enough cars have passed through to let the other direction go for awhile. And the way they do this is to detect a gap in the traffic flowing through the intersection. The assumption is that cars that have been waiting at the light will not produce a gap (barring some idiot who doesn't notice the light change of course). So a gap (again, talking about a gap exceeding the duration the light is configured for) means that the initial traffic has passed through, and now we're into traffic rolling up to the light, and it's light enough that a gap has appeared, so it's time to change and let the traffic waiting to go in the other direction have a turn.


This is how sensor based signal lights work. Do people not actually know this?
____________________________
King Nobby wrote:
More words please
#56 Aug 19 2014 at 2:32 PM Rating: Decent
Encyclopedia
******
35,568 posts
Dread Lörd Kaolian wrote:
For what it's worth even after the cost of the pavement cutting and materials, induction loops are wayyy less expensive to install than the cost of maintaining and or replacing a pressure plate.


Yeah. Mechanical plates are absurdly expensive to maintain. Not even a comparison. I'm shocked anyone actually would use them (and kinda wonder if whomever said that was just pulling the earlier posters leg). The loops are just wires under the asphalt. Much more simple.

Oh. And the reason you might not see them (responding to someone who mentioned looking for them), is because they're just wires under the asphalt. They install them when they install the asphalt. You wont see lines unless the wires failed and had to be repaired/replaced. In that case, you may see circular patterns in the asphalt where they cut down to the wires. But if it's a newish roadway (or has been resurfaced since the wires were last installed or replaced), you wont see any indication they are there.

For those who don't know how these work, there's nothing complex about them. They are just loops of wire under the roadway. They use the same electromagnetic principle of a hand crank generator to produce a current in the loop when a large metallic object (like a car) passes over the wires. This current trips a sensor which can do a variety of things based on how complex or simple the programming is. And this could be as simple as a 3 second timer on the light change that resets every time the loop sensor trips. Super easy.

Elinda wrote:
Rotaries and/or traffic circles. Everyone goes. No one stops. No light. No sound.

Nothing under the ground to maintain.


And no traffic control. The whole "traffic lights versus roundabouts" is a topic of itself.
____________________________
King Nobby wrote:
More words please
#57 Aug 19 2014 at 5:20 PM Rating: Good
GBATE!! Never saw it coming
Avatar
****
9,957 posts
gbaji wrote:
And no traffic control.

____________________________
remorajunbao wrote:
One day I'm going to fly to Canada and open the curtains in your office.

#58 Aug 19 2014 at 5:58 PM Rating: Excellent
Avatar
******
29,919 posts
DOT's like those because they don't have to pay for the electricity for the lights or hire someone to maintain it. People on the other hand appear to be too damned stupid to know how to drive in them. I see people driving the wrong way around them or doing attempted merges that end up with cars occupying the same spacetime more often than I should.
____________________________
Arch Duke Kaolian Drachensborn, lvl 95 Ranger, Unrest Server
Tech support forum | FAQ (Support) | Mobile Zam: http://m.zam.com (Premium only)
Forum Rules
#59 Aug 19 2014 at 6:17 PM Rating: Excellent
Avatar
******
29,919 posts
gbaji wrote:
Sir Xsarus wrote:
Generally car detection is on the stopped end to determine if there is a need to change the light, not on the moving cars. What are you basing this off of, speculation?


Observation. You've honestly never noticed this? I suppose it's possible that you've never lived in an area that uses loop sensors like this, but where I live nearly every light is equipped with them and it's incredibly obvious (if you pay attention) how the behavior works. In a quaint small town where a car rolling up to a light is a rare event, you could just use the sensors to trigger a change in the direction the car has arrived at. But in areas where there is constant traffic, this doesn't work (cause there's *always* a car on the cross traffic sensor). You have to have a method to determine if enough cars have passed through to let the other direction go for awhile. And the way they do this is to detect a gap in the traffic flowing through the intersection. The assumption is that cars that have been waiting at the light will not produce a gap (barring some idiot who doesn't notice the light change of course). So a gap (again, talking about a gap exceeding the duration the light is configured for) means that the initial traffic has passed through, and now we're into traffic rolling up to the light, and it's light enough that a gap has appeared, so it's time to change and let the traffic waiting to go in the other direction have a turn.


This is how sensor based signal lights work. Do people not actually know this?


Most of the lights just have more than one induction loop. An induction loop is literally just a fancy loop of wire, so they aren't expensive. Usually you'll have at least 3 per light per lane. One at the stop bar, one somewhere behind that one. usually fairly close (3-4 car lengths) so that one can operate as a failsafe in the event the main one fails. and one way back down the lane (8-12 car lengths). One change of signal from red, to yellow, to green again for all lights is one Cycle. Depending on where the car enters that cycle, the response of the light to the various sensors and what the light does varies. In the simplest scenario you are approaching a red light. Your car passes over the rearmost sensor, telling the controller box that there is at least one car present. Often the newer ones will count the cars that go over. It then looks at the first two sensors to determine how many cars are present and determine signal change priority. if there is just one car on the front sensor, it tells the controller to finish out it's normal time routine, and change whenever the sensor for the other side thinks there are no cars. If there is a car on the front sensor and one on the middle, it tells the controller that there are a bunch of cars over here, please expedite the change if possible and will sometimes change the light faster. If all three sensors are covered, it sends the "lane full" signal to the controller and puts it in "change signal as soon as possible if the other cross lane isn't also full" mode. For signalization at a green light, it reverses the sensor priority. the rear sensor once it is idle with no cars on it for a time tells the controller "ok, go ahead and think about changing the lights" The if there are no cars on the rear or the middle, it expedites that, and if there are no cars at all it switches to red sooner than later. The loops are timed so that the system knows what the speed limit is, and sometimes they can identify different masses and compensate. Your car has a different magnetic signature than the one behind you, and the newer smart controllers can track that as it goes over each sensor. if it takes you 20 minutes to get from the rear one to the front one, it knows the intersection is blocked and to try and let more traffic through in the blocked area to clear it. Then you have the networked signals where several interchanges can talk to each other and share sensor data.

In cities with constant traffic, they often just have them on a timer rather than worry about the sensors.
____________________________
Arch Duke Kaolian Drachensborn, lvl 95 Ranger, Unrest Server
Tech support forum | FAQ (Support) | Mobile Zam: http://m.zam.com (Premium only)
Forum Rules
#60 Aug 19 2014 at 7:13 PM Rating: Decent
Encyclopedia
******
35,568 posts
Dread Lörd Kaolian wrote:
if there is just one car on the front sensor, it tells the controller to finish out it's normal time routine, and change whenever the sensor for the other side thinks there are no cars. If there is a car on the front sensor and one on the middle, it tells the controller that there are a bunch of cars over here, please expedite the change if possible and will sometimes change the light faster. If all three sensors are covered, it sends the "lane full" signal to the controller and puts it in "change signal as soon as possible if the other cross lane isn't also full" mode. For signalization at a green light, it reverses the sensor priority. the rear sensor once it is idle with no cars on it for a time tells the controller "ok, go ahead and think about changing the lights" The if there are no cars on the rear or the middle, it expedites that, and if there are no cars at all it switches to red sooner than later.



Yup. Point being that if you leave a gap sufficiently large so that the sensor detects a "no car crossing the loop during X time period" condition, it affects the "time to change which side gets the green" decision. Hence, my original point about clueless people leaving overly large gaps causing the light to change, usually resulting in the people behind them having to stop for a light they would otherwise have been able to make it through.

It's really easy to see this in effect. Again, maybe other places don't do this (or other people aren't that observant), but around here pretty much all lights behave like this. I can't think of any that don't (maybe some of the ones downtown, but I avoid driving there like the freaking plague).
____________________________
King Nobby wrote:
More words please
#61 Aug 19 2014 at 8:21 PM Rating: Excellent
*****
10,601 posts
gbaji wrote:

This is how sensor based signal lights work. Do people not actually know this?
Did you read my second post? It's not generally how sensors work. This is sourced from the traffic planning and infrastructure development of SF for reference, so it's not like I'm just making it up because I talked to a civil engineer once, or observed roads as I drove along them.

I thought your description sounds interesting, if unrealistic from my admittedly limited knowledge from a few civil engineering classes so I investigated further.

Edited, Aug 19th 2014 9:26pm by Xsarus
____________________________
01001001 00100000 01001100 01001001 01001011 01000101 00100000 01000011 01000001 01001011 01000101
You'll always be stupid, you'll just be stupid with more information in your brain
Forum FAQ
#62 Aug 20 2014 at 10:53 AM Rating: Good
We have pressure plates, or what appears to be them, or we have standard timers. The timers change throughout the day to match expected traffic conditions, though.

While we do have cameras on a few intersections, all they're doing is photographing morons who run the red light.

I've never seen circular cutouts for induction loops, but it could be that they're just adding them in on the new roads or when they resurface the ones with pressure plates. Or something.

#63 Aug 20 2014 at 11:59 AM Rating: Decent
Encyclopedia
******
35,568 posts
Sir Xsarus wrote:
gbaji wrote:

This is how sensor based signal lights work. Do people not actually know this?
Did you read my second post? It's not generally how sensors work.


Yes, I did read it. I just disagree with your conclusion. And your statements don't really support your conclusion anyway:

Quote:
1) The extend the green light idea applies to minor streets crossing larger streets. The idea is that the smaller street will generally have a shorter light, but in the event there is an unusually large number of people it will extend the light by a small amount. Certainly not infinite, and the context is backed up traffic, not fast moving traffic on a main street.


This is you basically agreeing with me. Unless you have some alternative explanation as to how lights managed to detect "backed up traffic" other than being able to sense when cars are in a continuous unbroken line (which is *exactly* what I've been talking about). This is why I've been talking about "gaps" and not "speed". You don't speed up because going faster makes the light stay green. You speed up to catch up to the car in front of you, so that the sensor sees you as being in one unbroken line of cars with that car. Once someone leaves a gap, the light will change.

Quote:
2) Most intersections wouldn't have this, and will just use sensors to trigger the aforementioned minor street, or to trigger a turning light.


Most is a relative term. So "some" do, right? So there's no harm in closing the gap between you and the car in front of you, just in case, right? If a light has sensors at all, there's little reason not to have it programmed to detect traffic density when making cycle decisions. Programming is cheap. Making the lights smarter saves massive amounts of money.

Quote:
3) there are fully automated intersections that monitor continuously, and certainly there could be a case where both streets are monitored and could be extended either way, but it would be rare and not worth closing a gap to do.


And here you acknowledge what I'm talking about, but then claim it's not worth closing a gap. Um... Why not? And how would it be "rare"? What exactly do you think a fully automated intersection is doing? So we fully automate everything except the ability to detect the flow of traffic to determine whether to change the light? That seems like "not really automated at all". What conditions do you think a "fully automated" light should use to make cycle choices? I'm honestly curious here.

Quote:
This is sourced from the traffic planning and infrastructure development of SF for reference, so it's not like I'm just making it up because I talked to a civil engineer once, or observed roads as I drove along them.


It's sourced? Then source it. Saying "this is sourced" doesn't mean anything. Doubly so when what you are saying directly contradicts direct observations I make virtually every single day. There's a light at an offramp/intersection I drive every single day. That light will stay green a very very long time (because one side is an offramp from the freeway), but only as long as traffic continues to flow unbroken up to the light. If there's a gap, it will change to yellow immediately. This is trivially easy to test. All I have to do is slow down to allow a few extra car lengths between me and the car in front of me than I would normally set and the light will change to yellow as I'm approaching. You can literally see that once the gap between two cars hits that sensor (well, a car fails to cross the sensor in a given period of time), the light will change. Every. Single. Time.

Quote:
I thought your description sounds interesting, if unrealistic from my admittedly limited knowledge from a few civil engineering classes so I investigated further.


Then link your investigation. Again, I can get in my car *right now* and within 10 minutes directly observe this behavior. Maybe it's different where you live, but this behavior is common around here. I see it every day. And not just at that one intersection. I see this at lots of intersections all the time. I see a gap between cars crossing the sensor and I see the light turn yellow. All the time. It's how lights around here have worked for years. If the lights are on sensors at all (which most in San Diego are), they tend to exhibit this behavior. Cause, why not? It's a smart way to operate your lights.
____________________________
King Nobby wrote:
More words please
#64 Aug 20 2014 at 12:15 PM Rating: Decent
Encyclopedia
******
35,568 posts
Catwho wrote:
We have pressure plates, or what appears to be them, or we have standard timers.


Probably just what appears to be plates. My understanding is that no cities in the US have used pressure plates as traffic sensors for decades. So unless you've got really old roads (and they're somehow still working), you almost certainly have loops. As others have pointed out, quite often the loops are installed by cutting away lines in the road, which can make it look like a plate (they're usually in diamond or hexagonal shapes).

It's possible there's a pressure sensor, but those are usually going to be the tube types (like you see when folks are doing traffic flow studies).

Quote:
While we do have cameras on a few intersections, all they're doing is photographing morons who run the red light.


Most red light cameras use loops sensors to detect when a car enters the intersection on the red. It's possible that they use video or laser sensors only, but those are kinda rare (loops are really cheap to install and much less prone to failure).

Quote:
I've never seen circular cutouts for induction loops, but it could be that they're just adding them in on the new roads or when they resurface the ones with pressure plates. Or something.


Maybe. Or what you think are pressure plates are really loops and have been all along.
____________________________
King Nobby wrote:
More words please
#65 Aug 20 2014 at 12:21 PM Rating: Decent
Encyclopedia
******
35,568 posts
Oh Xsarus, let me be clear on something: This is usually behavior seen in more suburban areas. Downtown lights tend to rely on timers rather than sensors, and even when they have sensors, tend to be "dumb" in that they just sense if something is on the cross street so as to trigger a cycle once the timed period has elapsed. That's somewhat unique to downtown "grid" designs. Get out into the suburbs and you'll see a lot more lights that are designed to be intelligent. So much so that in many cases, they'll detect you coming and turn the light green before you come to a complete stop at a formerly red light.

Oh. And since I forgot in my earlier post: I completely disagree that closing the gap is somehow dangerous. How can that be? I'm not talking about riding someone's bumper here. I'm talking about simply not leaving an abnormally large space between you and the car in front of you. The scenario I'm talking about is when you are approaching a light that is green and there's a line of cars in front of you traveling through the light. The cars will have a natural spacing between them. I'm saying you should close the gap to match the gaps between the other cars. Not sure how this could be dangerous given that it's the same spacing that everyone else in the line is using.

What I see happen (a lot, because of the aforementioned light that's on my commute), is that the light will turn green and people will start moving through the intersection. Meanwhile the car in front of me is rolling along at a leisurely pace. I notice that at this cars current speed, there will be a large enough gap between him and the last car in the line ahead of us that the light will change. And sure enough, it will (every single time). However, if I am in that cars position (say the next day, approaching a similar line of cars at a similar distance), and I close that gap? The light stays green, not just for me, but several more cars following me.

Edited, Aug 20th 2014 11:27am by gbaji
____________________________
King Nobby wrote:
More words please
#66 Aug 20 2014 at 1:33 PM Rating: Good
We do have some really old roads. We get 30+ years out of some of them. Benefit of not having hard freezes all that often, and the sun shining bright enough during the hottest days to let the filler tar melt in and close the cracks.

The reason I suspect pressure plates is because I can drive up, miss the outlined areas on the road, back up, drive back in, back and forth a few times, until I hit the sweet spot and trigger a light change. You'd think that any kind of sensor wouldn't be so picky about where the car lands in relation to the cutouts on the road. Sucks when there's a giant truck or van whose wheel base is too wide to hit over the plated areas, too.
#67 Aug 20 2014 at 11:50 PM Rating: Excellent
Avatar
******
29,919 posts
The old pressure plates spanned the entire width of the road and were at least 8 feet wide. If it's smaller than that, It's 100% not a pressure plate. An induction loop cutout often looks something like this: [img]http://cronkitezine.asu.edu/specialprojects/photoenforcement/pics/Images_sp-200-sensor.jpg[/img]

The newer cut in ones use a large circular cutting head about 4 feet in diameter, leaving a perfectly round hole with a single wire channel running from that hole to the controller. These are often under pavement so you can't see them.

The newest ones are tiny and look like the thingies in here: http://wsdotblog.blogspot.com/2013/01/by-guest-blogger-mike-allende-hockey-is.html

I can't find a picture of the old pressure plate signal controllers, but they look identical to a truck weigh station scale pad, only shorter. I'm not finding a good ppicture of one of those either though.
____________________________
Arch Duke Kaolian Drachensborn, lvl 95 Ranger, Unrest Server
Tech support forum | FAQ (Support) | Mobile Zam: http://m.zam.com (Premium only)
Forum Rules
#68 Aug 20 2014 at 11:55 PM Rating: Excellent
**
505 posts
gbaji wrote:


Oh. And since I forgot in my earlier post: I completely disagree that closing the gap is somehow dangerous. How can that be? I'm not talking about riding someone's bumper here. I'm talking about simply not leaving an abnormally large space between you and the car in front of you. The scenario I'm talking about is when you are approaching a light that is green and there's a line of cars in front of you traveling through the light. The cars will have a natural spacing between them. I'm saying you should close the gap to match the gaps between the other cars. Not sure how this could be dangerous given that it's the same spacing that everyone else in the line is using.




Because you never know when someone is going to slam on their brakes. The object in front of you suddenly decelerating as you're accelerating could most definitely become a dangerous situation as that "same spacing everyone else is using" becomes "Why the **** did you just rear end me?"




Edited, Aug 21st 2014 1:57am by CoalHeart
____________________________
Never regret.To regret is to assume.
#69 Aug 21 2014 at 9:56 AM Rating: Excellent
Meat Popsicle
*****
13,666 posts
gbaji wrote:
Yup. Point being that if you leave a gap sufficiently large so that the sensor detects a "no car crossing the loop during X time period" condition, it affects the "time to change which side gets the green" decision. Hence, my original point about clueless people leaving overly large gaps causing the light to change, usually resulting in the people behind them having to stop for a light they would otherwise have been able to make it through.
And they're also tons of fun if you're on the bus, and the stoplight is on a uphill slope, and your like 3ish cars back in line.

Hate. Smiley: glare

Edit: Really I wish they'd just add an extra second to the darn things sometimes. Is it really so much longer to wait? Would keep all those buses and trucks and stuff from clogging up the light.

Edited, Aug 21st 2014 8:57am by someproteinguy
____________________________
That monster in the mirror, he just might be you. -Grover
#70 Aug 21 2014 at 12:04 PM Rating: Decent
Encyclopedia
******
35,568 posts
CoalHeart wrote:
gbaji wrote:
Not sure how this could be dangerous given that it's the same spacing that everyone else in the line is using.


Because you never know when someone is going to slam on their brakes. The object in front of you suddenly decelerating as you're accelerating could most definitely become a dangerous situation as that "same spacing everyone else is using" becomes "Why the **** did you just rear end me?"


No more dangerous than any other time you are approaching a car from behind. This is basic driving skills at work. Learning how to time your approach to a slower moving vehicle ahead of you is something you should know how to do safely, or you'll eternally be rear ending people. You don't accelerate until the gap is closed, you accelerate to increase your speed relative to the car in front of you, then slow down to match speeds as you approach. If the car in front of you slows down, you slow down slightly faster to match speeds. You do this every day when driving, so I'm not sure how this magically becomes a problem just in this one case.

Edited, Aug 21st 2014 12:05pm by gbaji
____________________________
King Nobby wrote:
More words please
#71 Aug 21 2014 at 3:44 PM Rating: Good
**
505 posts
gbaji wrote:
CoalHeart wrote:
gbaji wrote:
Not sure how this could be dangerous given that it's the same spacing that everyone else in the line is using.


Because you never know when someone is going to slam on their brakes. The object in front of you suddenly decelerating as you're accelerating could most definitely become a dangerous situation as that "same spacing everyone else is using" becomes "Why the **** did you just rear end me?"


No more dangerous than any other time you are approaching a car from behind. This is basic driving skills at work. Learning how to time your approach to a slower moving vehicle ahead of you is something you should know how to do safely, or you'll eternally be rear ending people. You don't accelerate until the gap is closed, you accelerate to increase your speed relative to the car in front of you, then slow down to match speeds as you approach. If the car in front of you slows down, you slow down slightly faster to match speeds. You do this every day when driving, so I'm not sure how this magically becomes a problem just in this one case.

Edited, Aug 21st 2014 12:05pm by gbaji



There is no "matching" if a car suddenly slams on their brakes in front of you or another car zips from their lane into the gap between you and the car in front of you.

You're seriously Underestimating the distance a car travels even at "low" speeds and Overestimating Human reaction speed..


But whatever, I'm not going to argue with you as you contort the laws of physics.




Edited, Aug 21st 2014 5:46pm by CoalHeart
____________________________
Never regret.To regret is to assume.
#72 Aug 21 2014 at 7:38 PM Rating: Decent
Encyclopedia
******
35,568 posts
Is it that I'm just not explaining what I'm talking about clearly enough? Because I'm reading the responses and not getting why folks are responding so negatively. Let me repeat: I'm not talking about driving at an unsafe distance or speed at any point.

Imagine the car in front of you is traveling at some speed. Doesn't matter what it is. Let's pretend that at whatever speed that car is traveling at, you can safely follow him at the same speed at a distance of 50'. If he slams on the breaks, you are far enough back that you can react and not run into him. OK? Go it? Safe distance.

Now. Imagine that instead of driving at the same speed as this car at 50' distance, you are instead 150' behind it. Since this is a long enough gap that the traffic light that is a mile ahead of you will trigger a cycle change, you decide to close the distance. You speed up a bit, so that you are overtaking the car. Then, as you get closer you reduce your speed, so that you come to a smooth matching speed at a safe 50' distance behind the car. At no point are you ever driving too close to the other car. As you close to that 50' distance you are also slowing down, so there's no more danger doing this than just driving along down the road.

You're treating this like I'm proposing some crazy dangerous maneuver or something. I'm not. This is normal driving that most even semi-competent drivers manage to do every single day without getting into a collision. All I'm saying here is that if you pay attention to the road conditions up ahead of you, you can make minor adjustments to your speed so as to adjust the distance between you and the car ahead of you well ahead of the intersection and avoid leaving large gaps that may result in unwanted traffic light changes without putting anyone in danger. I'm not advocating roaring up at high speed to get right on someone's rear bumper. Just look ahead of you, notice the traffic pattens and avoid leaving overly large gaps between you and the car in front of you. It's not rocket science or anything.

Sheesh! You'd think I was proposing that people sacrifice babies or something.
____________________________
King Nobby wrote:
More words please
#73 Aug 21 2014 at 8:24 PM Rating: Excellent
*****
10,601 posts
Quote:
It's sourced? Then source it. Saying "this is sourced" doesn't mean anything. Doubly so when what you are saying directly contradicts direct observations I make virtually every single day
Smiley: dubious I did, I told you I asked an engineer who works with the department of transportation for SF, and knows what the various traffic light systems in place are. They would also be familiar with SD although not as intimately. I'm not going to give you their phone number, what the f*ck is wrong with you.

for the rest, apparently your reading comprehension is terrible, so I'm not going to bother re-posting what I wrote. I'm sure most of the posters had no trouble understanding exactly what I was saying, which was my purpose anyway, because experience has clearly shown me that discussing anything with you is about as fruitful as throwing limes into the air and hoping they turn into drinks.

For reference, aiming for a 1.5 second gap between cars is not safe, especially when you're watching a light hoping to make it through a light before it changes.

Edited, Aug 21st 2014 9:29pm by Xsarus
____________________________
01001001 00100000 01001100 01001001 01001011 01000101 00100000 01000011 01000001 01001011 01000101
You'll always be stupid, you'll just be stupid with more information in your brain
Forum FAQ
#74 Aug 25 2014 at 7:07 PM Rating: Decent
Encyclopedia
******
35,568 posts
Sir Xsarus wrote:
Quote:
It's sourced? Then source it. Saying "this is sourced" doesn't mean anything. Doubly so when what you are saying directly contradicts direct observations I make virtually every single day
Smiley: dubious I did, I told you I asked an engineer who works with the department of transportation for SF, and knows what the various traffic light systems in place are. They would also be familiar with SD although not as intimately. I'm not going to give you their phone number, what the f*ck is wrong with you.


That's not a source. That's an anecdote. A source requires that you provide *me* some information to verify the source of your information. Saying "I have a friend who says..." is just you saying that. That doesn't mean it's wrong or anything, but by no definition is that a source (at least in this context). I'll point out btw, that unlike other posters on this forum, I don't demand a source or cite for everything someone says. I'm perfectly fine with you just saying "I have a friend in the SF dot who says ...". Say that, and I'll place weight on it accordingly. But be honest about it.

Quote:
for the rest, apparently your reading comprehension is terrible, so I'm not going to bother re-posting what I wrote. I'm sure most of the posters had no trouble understanding exactly what I was saying, which was my purpose anyway, because experience has clearly shown me that discussing anything with you is about as fruitful as throwing limes into the air and hoping they turn into drinks.


Which is strange, because I haven't failed to understand anything you've written in this thread. You, on the other hand, seem to almost intentionally choose to misunderstand what I'm saying. Apparently, purely because I'm saying it and you want to disagree or something. It's pretty nutty. Nothing I'm saying is even remotely unusual or controversial. You're just choosing to argue against it anyway.

Quote:
For reference, aiming for a 1.5 second gap between cars is not safe, especially when you're watching a light hoping to make it through a light before it changes.


And here's a great example. I've said repeatedly that whatever distance you should seek is whatever the "safe distance" is. I don't even recall in what context I mentioned 1.5 seconds, but you managed to completely miss the point by focusing on made up example numbers. Let me say this again: I don't care what the actual distance is in feet, or in seconds. I'm talking about the normal safe distance you follow other cars. The lights are programmed to see gaps in a line of cars greater than that distance/time (whatever the **** it is for that particular light). It cannot possibly be dangerous for you to close the gap from a distance well larger than the safe distance up to the safe distance.

I've said this like 5 times now, but you keep managing to ignore it. You are driving behind another car at a distance that is twice the safe distance. If you fail to close that gap, many lights (at least around here) will trigger a light change. In that case you should close that gap so as not to ***** over the line of people behind you. Period. There's nothing unsafe about this. There can't be anything unsafe about this. Because at all times you are equal to or greater than the "safe distance" behind the other car.


Do you get this yet? Or do I need to repeat the same freaking thing 10 more times before it sinks in?

Sheesh! Willful ignorance is annoying as hell.

Edited, Aug 25th 2014 6:09pm by gbaji
____________________________
King Nobby wrote:
More words please
#75 Aug 26 2014 at 9:14 AM Rating: Excellent
*****
10,601 posts
No willful ignorance on my part, still unable to read, perhaps I'll clarify what happened.

1) I read your post, based on what I know of civil engineering design, I thought this seemed unlikely based on how you presented it at first especially.

2) I inquired and found that it actually was a realistic scenario, but fairly rare. I tried to explain exactly when it happened, and how in a more detail than you had or were able as you didn't have a direct source.

3) My only disagreement was that I thought the idea of closing a gap while going towards a light that may or may not change is dangerous, and given how often it will actually be useful is probably not worth it as a matter of course when approaching arbitrary light X, which is certainly how you presented it. You here seemed to think that because I posted I was saying you were wrong about everything.

The idea of closing a gap to prevent a light from changing is most likely only going to occur in a situation where a light has quite recently changed on a side street with a fair amount of traffic backed up behind it. This is the scenario these sensors are looking for and are put in place to ameliorate. From my perspective, this means that most lights won't behave this way, and I still find it dangerous to accelerate in case you can close the gap enough. It's setting you up to not be able to stop in time if the light changes, or if the person in front of you gets a yellow an decides to stop when he may have been able to go through, you're accelerating towards him, and it puts you at greater risk. why are you so far behind to begin with? Do you have to speed to close the gap? Given that you were most likely stopped, there shouldn't really be a gap. The scenario is where you're coming up to an intersection after most of the traffic has cleared and you accelerate hoping to get through before it changes. That's increasing your risk.

Quote:
That's not a source. That's an anecdote
I don't know if asking the person who knows exactly what the system does and has helped design it is an anecdote. If you asked me how something I wrote worked, I'd think I'd be the authoritative source. I mean you don't have to believe me, but it's not like I asked some random person, or I mentioned talking with a friend who had read an article or something. Take it or leave it, it is still true.

Edited, Aug 26th 2014 10:18am by Xsarus
____________________________
01001001 00100000 01001100 01001001 01001011 01000101 00100000 01000011 01000001 01001011 01000101
You'll always be stupid, you'll just be stupid with more information in your brain
Forum FAQ
#76 Aug 26 2014 at 10:16 AM Rating: Excellent
Meat Popsicle
*****
13,666 posts
I imagine the problem is probably pretty variable.

I know of 2 lights on my commute that have the "light changes when no one is crossing the sensor" thing. One of which is the previously mentioned hill where the bus has problems (still hate it with a passion). The other is a variable left-hand turn light. Most of the others are linked because it's a major roadway and they need the lights timed properly to keep traffic moving.

On the other hand I remember more of them growing up in my little town. There was only one section of road near the freeway where they linked the lights. Most of the cross-streets had little or no traffic and thinking back it made a lot of sense to do it that way. Also probably worth pointing out that many lights will link for part of the day, and go a different pattern later at night. Your commute at 2am can feel a lot different than at 5pm, for reasons other than the more obvious.

Also, something, something, my dad worked on that stuff when I was a kid so I'm an expert, etc.
____________________________
That monster in the mirror, he just might be you. -Grover
Reply To Thread

Colors Smileys Quote OriginalQuote Checked Help

 

Recent Visitors: 305 All times are in CST
Anonymous Guests (305)