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Old 01-07-2019, 11:14 AM
 
8,312 posts, read 4,009,469 times
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Quote:
Originally Posted by djsuperfly View Post
Not sure what you're trying to say. There are intersections where it works and intersections where it doesn't.

I'm saying you will never eliminate judgment from the driving equation as long as there are human drivers. The more you keep moving the goalposts of what "works" and "doesn't work" (it's always to the latter, control signals and signs are seldom removed) the less experience people get in making judgments and thus the less competent they are when they must make them.


And even in intersections where it "doesn't work" there are times when it does and times when it does not.
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Old 01-07-2019, 11:22 AM
 
8,312 posts, read 4,009,469 times
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Quote:
Originally Posted by djsuperfly View Post
I would guess money is probably the reason, eh?

It's really not necessary any more to spend $50K to rip up an intersection and bury pressure plates to detect traffic. Optical detection is cheap and accurate. They sure didn't need to do that to install red light cameras, did they? A cheap motion sensor can detect an approaching vehicle. The electronics that manage the intersection are simple. There's probably an app for that.


Better traffic management can delay or eliminate the need to spend millions to widen the road. Not to mention reducing cumulative driver frustration can reduce accidents.
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Old 01-07-2019, 11:26 AM
 
8,312 posts, read 4,009,469 times
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Quote:
Originally Posted by rstevens62 View Post
This also could be from the old days, when there was some corruption, in relation to timing traffic control devices, so drivers waste as much fuel as possible, I know this happened to some degree.

It seems to be much worse in small towns especially where a state highway passes through. It's like they resent traffic passing through and want to annoy them. Or figure the slower you make them go and more often you make them stop, the more likely they are to stop at a store or restaurant and contribute to the local economy.
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Old 01-07-2019, 12:33 PM
 
Location: Houston/Brenham
3,752 posts, read 4,342,191 times
Reputation: 6610
Quote:
Originally Posted by Steve McDonald View Post
Outlawing all left turns, is the better solution. Go a block past an intersection, make three right turns and then go straight across the intersection.
Quote:
Originally Posted by astrohip View Post
That's not a good universal solution. There are some very busy intersections that allow left turns, some from two lanes there is so much traffic. Putting all that traffic into a local neighborhood, or worse, into a corner shopping center, would create massive headaches--accidents and more.

Quote:
Originally Posted by RcHydro View Post
I guess some one missed the sarcasm that 3 rights make a left.
I apologize if the poster (which wasn't you) was being sarcastic. I completely missed it, and still don't see it.

Usually that's where a helps.
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Old 01-07-2019, 12:40 PM
 
1,871 posts, read 448,940 times
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Quote:
Originally Posted by rstevens62 View Post
Ive noticed alot more left hand turn traffic lights are now flashing yellow, instead of the red arrow, meaning, if its safe to make the left hand turn, go ahead and do it, instead of needlessly waiting for the light to cycle and get a green arrow.


Nothing bothers me more on the road than having to sit idle for no reason whatsoever, Ive been in plenty of left hand turn lanes, where you do have to wait for the green arrow to go, and majority of the time, the whole time you are sitting there with a red arrow, they are plenty of safe opportunities to make the turn.
Not exactly what that means... a yellow flashing arrow is the same as a yellow flashing caution light. Depending on the turn you are (or aren't) making, you may or may not have the right of way. If you have a flashing yellow arrow left, the oncoming (straight) traffic has a green light. Oncoming green still has the right of way, if you turn left on flashing yellow in front of someone going straight on green you're automatically at fault.
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Old 01-07-2019, 01:11 PM
 
Location: BFE
788 posts, read 197,056 times
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If nobody's coming, I just run them.
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Old 01-07-2019, 01:17 PM
 
8,312 posts, read 4,009,469 times
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Quote:
Originally Posted by Gatopescado View Post
If nobody's coming, I just run them.

And maybe these intersections that are not equipped to detect your car approaching the red and turn the signal green are well equipped to detect your car moving through the red and mail you a ticket!
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Old 01-07-2019, 02:53 PM
 
6,360 posts, read 6,749,407 times
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If you watch and pay attention to the news....you'd know that because there'd be a story on it.
Even if not, something like that doesn't stay a secret for long.

Unless they put the sensors at EVERY light, in EVERY direction you could still make your'e own decision about waiting for the light or not, at intersections where there's no sensor. Just like red light and speed cameras now....just don't do it where there's a camera.
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Old 01-07-2019, 10:25 PM
 
70 posts, read 253,670 times
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A Traffic Engineer here with some background....

In the distant past all signalized intersections consisted of usually two phases and left turns were made on a green ball (proper terminology), if safe. These were called permissive left turns.

As traffic volumes increased, accident rates went up, technology improved so left turn arrows were added. These are called protected left turns.

Protected left turns are the safest but they are also the least efficient. Permissive left turns are the least safe, but they are most efficient. So it's always been a balancing act between safety and efficiency. In the past it's always been, "pick one".

Protected/permissive left turn indications are an attempt to have the best of both worlds. They can work in several ways, but most common in the US is for left turning vehicles to initially see a green arrow (which gives them the right of way), which then goes to a green ball (requiring additional left turners to yield right of way). There are many ways to pull this off, and the Feds are trying to get all states to standardize on just how. Research has shown flashing yellow arrows are usually more safe than going to green balls as they grab drivers' attention more, although they mean the same thing. I will tell you that based upon my years of experience the average driver is pretty dense, usually driving on autopilot and not paying attention so "weird" indications like flashing yellow arrows are often used. However once people get familiar with them, they are quite effective. One of the frustrations of traffic engineering is you have to design for the least common denominator (i.e., the dumbest driver on the road)

There are a lot of other considerations before these can be implemented like traffic turning volumes and if there is any sort of traffic signal coordination going on. And these protected/permissive signals can also be run where there green ball comes on first, then towards the end of the approach's green, the left goes to a green arrow. These are called permissive/protected lefts. Traffic signals can even switch between the two modes during the day due to changing traffic patterns. This usually isn't a good thing as drivers get used to expecting certain patterns and don't handle change well.

So, TL;DR, left turns with green arrows going to green balls are a way to increase the throughput of an intersection without compromising safety too much.
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Old Yesterday, 09:11 AM
 
Location: Houston/Brenham
3,752 posts, read 4,342,191 times
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Quote:
Originally Posted by OtherHand View Post
A Traffic Engineer here with some background....
Thanks, really good info!
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