Best / worst region-specific practices?

[roadman65]

Texas with their urban freeway frontage roads.  It allows you to access all cross streets ecspecially the ones that do not interchange.

New Jersey jughandles are good at keeping slow traffic to the right.  Not good on two lane roads, though.
Jersey Freeways are good as it keeps traffic signals out of urban areas, Paramus, Hackensack, Clifton,etc.

DE, CA, NJ, IL are all good with two left turn signal heads and spacing out through signal heads so the light can be seen when behind a truck.  Even at 300 feet behind a delivery truck, the view of the signal is blocked, especially here in Florida.

Florida stinks with signals and timings.  Too many of them in Orlando and no signal in Florida is state operated even on state highways!  They are run locally and local engineers do not look at highways as such, but as another street and therefore time the lights to short wait times on side streets during off peak hours thus causing stop and go on large arteries like John Young Parkway, and Orange Blossom Trail.

Plus, in Florida you cannot proceed across the stop bar unless you can make the left turn.  New Jersey allows left turn motorists to pull out into the intersections to make a left in heavy traffic, so if the signal turns you can still go on yellow or red.  Florida, we have to wait for the next green to try again.  Luckily most signals here have a protected left arrow or else you would have to wait four or five changes to turn.

[1995hoo]

....

Plus, in Florida you cannot proceed across the stop bar unless you can make the left turn.  New Jersey allows left turn motorists to pull out into the intersections to make a left in heavy traffic, so if the signal turns you can still go on yellow or red.  Florida, we have to wait for the next green to try again.  Luckily most signals here have a protected left arrow or else you would have to wait four or five changes to turn.

Hmmm, I've had people in Florida honk at me when I waited behind the stop bar while waiting to turn left. I had no idea what Florida law might be, I just seldom pull out into the intersection anymore (even though I used to do it) because over the years I've found that as large SUVs and pickups become more and more common, I can see better if I stay back behind the stop line and pull farther to the left in the turn lane.

I seem to recall reading a list of states in which it is illegal to be in the intersection when the light turns red (meaning the "wait in the intersection" move would be illegal if you clear it after the light is red), but I can't find that list now.

[NE2]

Plus, in Florida you cannot proceed across the stop bar unless you can make the left turn.

[citation needed]
I don't see anything clearly stating this:
http://www.leg.state.fl.us/Statutes/index.cfm?App_mode=Display_Statute&Search_String=&URL=0300-0399/0316/Sections/0316.075.html
http://www.flhsmv.gov/handbooks/EnglishDriverHandbook.pdf (p. 41)

And note this: http://www.dot.state.fl.us/safety/ped_bike/laws/ped_bike_pedLaws2.shtm "For a driver still waiting in the intersection to make a permitted left turn..."

[roadman65]

....

Plus, in Florida you cannot proceed across the stop bar unless you can make the left turn.  New Jersey allows left turn motorists to pull out into the intersections to make a left in heavy traffic, so if the signal turns you can still go on yellow or red.  Florida, we have to wait for the next green to try again.  Luckily most signals here have a protected left arrow or else you would have to wait four or five changes to turn.

Hmmm, I've had people in Florida honk at me when I waited behind the stop bar while waiting to turn left. I had no idea what Florida law might be, I just seldom pull out into the intersection anymore (even though I used to do it) because over the years I've found that as large SUVs and pickups become more and more common, I can see better if I stay back behind the stop line and pull farther to the left in the turn lane.

I seem to recall reading a list of states in which it is illegal to be in the intersection when the light turns red (meaning the "wait in the intersection" move would be illegal if you clear it after the light is red), but I can't find that list now.

Funny. Here in Orlando almost everbody does it.  Only on Millenia Boulevard at Millenia Lakes Drive you must pull out as the median landscape prevents you from seeing on coming traffic when behind the line.

[national highway 1]

But I hear other states replace signs with Clearview for no reason at all, and still others, like MA and WI, shun it.

Also Utah and Colorado shun Clearview too. Unsure whether New Mexico uses Clearview at all.

Interstate state shield design (green and white with a widened generic outline)

I cannot visualize this.  got a photo?

if contractors have the freedom to put up whatever they want to, then why are there so few pelican shields? 

What is a pelican shield?

[kphoger]

Only on Millenia Boulevard at Millenia Lakes Drive you must pull out as the median landscape prevents you from seeing on coming traffic when behind the line.

Well that wasn't planned very well... 

[agentsteel53]

What is a pelican shield?

[Revive 755]

Plus, in Florida you cannot proceed across the stop bar unless you can make the left turn.  New Jersey allows left turn motorists to pull out into the intersections to make a left in heavy traffic, so if the signal turns you can still go on yellow or red.  Florida, we have to wait for the next green to try again.  Luckily most signals here have a protected left arrow or else you would have to wait four or five changes to turn.

I'm mixed on whether that is really such a good thing - I've seen many instances where two or three cars will get into the intersection then turn when the light changes.  Problem is they don't clear the intersection before the perpendicular movements get a green ball or arrow, and can start to significantly eat the green time for these movements.  The practice also leads to a number of left turn crashes where the vehicle turning left thinks the opposing through vehicle is going to stop for the yellow so they start their left turn.  Problem is the through vehicle is instead pushing the light so they cream the left turner.

The problem with a blanket ban on the practice is the case where a vehicle starts to turn left permissively but has to stop the turn due to an opposing vehicle that has turned out of a nearby driveway.

[myosh_tino]

'61 spec US-395 green and white shield for California?

That's the shield I requested and received from you.  Actually you sent me a white '61 spec US shield and I modified it to try to replicate the older outline US shield California used on guide signs.  I know it's not quite right but it was close enough for what I wanted it for.  Anyways, both shields (white and green) were added to my library.

[vdeane]

Sigh. What's so bloody hard about this? Yellow trap is for *left* turns at the end of a phase, when the other direction still has green (kphoger is correct). It happens whenever you have a lead-lag phase (which is often necessary for good signal progression), and other than signal modifications such as the FYA, the only solution is to change it to a protected left turn.

So next time you're sitting at a red arrow, knowing it's safe to turn but legally prohibited from doing so, remember that it could have been a flashing yellow. And that if it's on a busy corridor with many lights, there's a good chance that it could not have been a normal doghouse.

Doghouses work just fine in this situation here in upstate NY.  I don't see how the yellow trap is anything but badly timed signals.  Waiting two seconds to start the other side's green while the light is yellow and turning red won't kill signal progression.

Plus, in Florida you cannot proceed across the stop bar unless you can make the left turn.  New Jersey allows left turn motorists to pull out into the intersections to make a left in heavy traffic, so if the signal turns you can still go on yellow or red.  Florida, we have to wait for the next green to try again.  Luckily most signals here have a protected left arrow or else you would have to wait four or five changes to turn.

I'm mixed on whether that is really such a good thing - I've seen many instances where two or three cars will get into the intersection then turn when the light changes.  Problem is they don't clear the intersection before the perpendicular movements get a green ball or arrow, and can start to significantly eat the green time for these movements.  The practice also leads to a number of left turn crashes where the vehicle turning left thinks the opposing through vehicle is going to stop for the yellow so they start their left turn.  Problem is the through vehicle is instead pushing the light so they cream the left turner.

The problem with a blanket ban on the practice is the case where a vehicle starts to turn left permissively but has to stop the turn due to an opposing vehicle that has turned out of a nearby driveway.

At least in NY, our law is that only the first car in the left turn lane can pull forward; others have to wait behind the stop line.  Nobody follows it, though.

[roadfro]

Sigh. What's so bloody hard about this? Yellow trap is for *left* turns at the end of a phase, when the other direction still has green (kphoger is correct). It happens whenever you have a lead-lag phase (which is often necessary for good signal progression), and other than signal modifications such as the FYA, the only solution is to change it to a protected left turn.

So next time you're sitting at a red arrow, knowing it's safe to turn but legally prohibited from doing so, remember that it could have been a flashing yellow. And that if it's on a busy corridor with many lights, there's a good chance that it could not have been a normal doghouse.

Doghouses work just fine in this situation here in upstate NY.  I don't see how the yellow trap is anything but badly timed signals.  Waiting two seconds to start the other side's green while the light is yellow and turning red won't kill signal progression.

I don't think you're understanding the nature of what the yellow trap is. Yellow trap occurs when a permitted left turn (using standard doghouse) terminates with the adjacent green, but opposing through traffic is already green and is remaining green due to a lagging left turn in the opposite direction. The "trap" occurs when a driver pulling out to make the permitted left thinks the opposing through traffic will also be ending with the adjacent through traffic, turning to clear the intersection in front of oncoming traffic that is not stopping.

See the link NE2 posted in an earlier reply. The animation on the page demonstrates the yellow trap pretty clearly, alongside another animation which shows how an FYA signal avoids the problem.

[NE2]

Doghouses work just fine in this situation here in upstate NY.  I don't see how the yellow trap is anything but badly timed signals.  Waiting two seconds to start the other side's green while the light is yellow and turning red won't kill signal progression.

The other side's green *is not starting*. It's already green, and is staying green.

[agentsteel53]

That's the shield I requested and received from you.  Actually you sent me a white '61 spec US shield and I modified it to try to replicate the older outline US shield California used on guide signs.  I know it's not quite right but it was close enough for what I wanted it for.  Anyways, both shields (white and green) were added to my library.

yeah sometime I need to assemble the '57 spec outline shields.  I have the spec, but have been too lazy to turn a lengths-and-radii description into a working vector.

no one's ordered one from me yet... would be cool to make one, even if scaled down a bit!

[vdeane]

Sigh. What's so bloody hard about this? Yellow trap is for *left* turns at the end of a phase, when the other direction still has green (kphoger is correct). It happens whenever you have a lead-lag phase (which is often necessary for good signal progression), and other than signal modifications such as the FYA, the only solution is to change it to a protected left turn.

So next time you're sitting at a red arrow, knowing it's safe to turn but legally prohibited from doing so, remember that it could have been a flashing yellow. And that if it's on a busy corridor with many lights, there's a good chance that it could not have been a normal doghouse.

Doghouses work just fine in this situation here in upstate NY.  I don't see how the yellow trap is anything but badly timed signals.  Waiting two seconds to start the other side's green while the light is yellow and turning red won't kill signal progression.

I don't think you're understanding the nature of what the yellow trap is. Yellow trap occurs when a permitted left turn (using standard doghouse) terminates with the adjacent green, but opposing through traffic is already green and is remaining green due to a lagging left turn in the opposite direction. The "trap" occurs when a driver pulling out to make the permitted left thinks the opposing through traffic will also be ending with the adjacent through traffic, turning to clear the intersection in front of oncoming traffic that is not stopping.

See the link NE2 posted in an earlier reply. The animation on the page demonstrates the yellow trap pretty clearly, alongside another animation which shows how an FYA signal avoids the problem.

You're describing a situation that is completely different than what is shown in the animation you are citing.  In the animation, the doghouse is in the protected phase for the left along with a green for straight traffic in that direction; the other side is red, as is required for the protected left.  The light goes green for all traffic in the opposing direction at the same time as the light goes yellow for the direction the animation is using to illustrate "yellow trap".  That is when the accident to illustrate the yellow trap occurs.  Had the light waited to go green for the opposing direction until after the yellow phase was over, there would be no yellow trap, and no need for a FYA.

Doghouses work just fine in this situation here in upstate NY.  I don't see how the yellow trap is anything but badly timed signals.  Waiting two seconds to start the other side's green while the light is yellow and turning red won't kill signal progression.

The other side's green *is not starting*. It's already green, and is staying green.

That is not what is shown in the animation, and if you have a permissive left ending with the other end staying green like that, you have a poorly timed signal.

I think you mentioned cost earlier too, but isn't it cheaper to re-time a signal than it is to replace it completely with a FYA?  One requires the cost of changing one line of a database: $0.  The other involves the cost of new signal heads: $(a lot).

[NE2]

You're describing a situation that is completely different than what is shown in the animation you are citing.  In the animation, the doghouse is in the protected phase for the left along with a green for straight traffic in that direction; the other side is red, as is required for the protected left.  The light goes green for all traffic in the opposing direction at the same time as the light goes yellow for the direction the animation is using to illustrate "yellow trap".

The fuck? You're talking about this animation, right? http://projects.kittelson.com/pplt/LearnAbout/Learn3.htm I count 10 seconds between both directions getting a green and northbound turning yellow. That would probably be at least a minute in the real world.

if you have a permissive left ending with the other end staying green like that, you have a poorly timed signal.

You bloody well don't if the lead-lag is necessary for efficent progression with adjacent intersections.
http://midimagic.sgc-hosting.com/progreso.htm

(not the best animation, but the only one I could find; note how the center two intersections have offset green phases)

I haven't read the whole thing, but http://midimagic.sgc-hosting.com/lagtrap.htm looks like a good description of the problem and solutions.

[vdeane]

I think my computer botched the rendering the first time I saw it, because it now conforms to what you're saying.  That or my brain was spacing out.  Neither would surprise me.

I think this comes down to the fact that upstate NY doesn't use lead-lag, in fact, we don't place any kind of priority on efficient progression at all.  The theory is that if you want free-flow, you should quit complaining and get on the freeway, and tough if there aren't any around.  At one time the city plans for upstate included freeways parallel to every high traffic corridor of the type you describe.  It's normal for vehicles to sit at every light in such corridors here, and it's the accepted norm.  The only exceptions I can think of are NY 441 (which is a recent exception at that, and probably the reason why it's getting the first FYA in the state) and NY 332 (which accomplishes this by screwing over the side streets and giving them only two seconds of green for every five minutes NY 332 gets; this was probably done because NY 332 should have been made a freeway 20-30 years ago but probably never will be anything more than the expressway it is now).