Best / worst region-specific practices?

[vdeane]

No more so than a five lamp tower.  You still can't tell what signal opposing traffic is getting.  A simple solution is to simply not allow the left turn if opposing traffic has a green light and a green left arrow instead of the Dallas phasing bullshit.

Agreed.  The FYA is only necessary because of stupid signal phasing in some states combined with stupid drivers.  A properly phased signal has no such thing as yellow trap, especially if the laws are properly set to legally allow vehicles to be in an intersection with a red light provided that they entered when the light was not red and leave at the earliest opportunity.  If Dallas phasing produces these problems, the solution is not FYAs, but to outlaw Dallas phasing.

[Ace10]

No more so than a five lamp tower.  You still can't tell what signal opposing traffic is getting.  A simple solution is to simply not allow the left turn if opposing traffic has a green light and a green left arrow instead of the Dallas phasing bullshit.

Agreed.  The FYA is only necessary because of stupid signal phasing in some states combined with stupid drivers.  A properly phased signal has no such thing as yellow trap, especially if the laws are properly set to legally allow vehicles to be in an intersection with a red light provided that they entered when the light was not red and leave at the earliest opportunity.  If Dallas phasing produces these problems, the solution is not FYAs, but to outlaw Dallas phasing.

Dallas Phasing and the FYA are supposed to prevent the yellow trap, not produce it. The problem with Dallas Phasing, however, is that the permissive left turn is shown as a green ball while the through movement is shown as a red ball.

Depending on traffic patterns, a FYA being displayed at the same time that the through movement has a red light can be beneficial. If the vehicles turning left can still make it through the intersection on a FYA, there's no reason to prevent them by displaying red on all signals. At a certain time of day, there just may be a lot of people in the opposing direction turning left, but not much through traffic.

Dallas Phasing and the FYA both allow the subject left-turning vehicles to turn, but the FYA has the added benefit of not displaying conflicting signals at the same time for left-turn and through traffic, and also does not require special modifications to the signals to prevent through traffic from seeing the left-turn signal. The arrow itself also clearly communicates what direction the lane is for - unfamiliar drivers in a heavy rainstorm may not see the "Left Turn Signal" and "Left Turn Yield on Green" signs, and try to go straight through the intersection, for instance. The FYA removes this kind of ambiguity and, in my opinion, doesn't introduce more ambiguity than it removes.

This being said, there's already a thread about the FYA with a ton of information and opinion about it.

[vdeane]

That's why you're supposed to have a doghouse, and not a left turn signal, in that situation.  Left turn signals should only be used for fully protected left turns, and those should be avoided wherever possible.

All of these problems could be avoided by ending the overuse of dedicated left turn signals.  Upstate NY gets it right: doghouses if a protected left turn phase is needed, left turn signal as a last resort only.

[sipes23]

Wisconsin:
Like: Many Milwaukee traffic signals go to flashing yellow/red when traffic dies down.
Like: Passing areas on the right when the left turn is taking too long on rural roads.
Like: The increasing number of roundabouts.

Michigan:
Like: As described in a previous post, two lane roads have passing zones every few miles.
Not sure: Michigan left.

Illinois:
Like: Generous interpretation of speed limits on Chicago area interstates (generally).
Dislike: Roads seem to be designed to generate the maximum number of stops via traffic signals (IL 59, I'm looking at you).
Dislike: General poor quality of pavement. Particularly noticeable after a trip to Wisconsin.

[DandyDan]

In Nebraska:
1.  I like the diagrammatic intersection signs, even if only for the uniqueness, although they seem inconsistently applied even in rural areas. (I've never seen one in a town.)
2. I'm not a fan of the link and spur numbering (lettering?) system.  should just be all numbers.
3. I work overnights, and there is no rhyme or reason to which traffic signals at night are blinking and which ones you have to sit thru, plus there is no logic to how they work, either.  One of them at night I have to pass through on the way home automatically gives a left-turn signal to oncoming traffic even when there is no left-turning traffic, which is pretty much every time. (This may be strictly an Omaha problem, or an Omaha area problem.)

[roadfro]

That's why you're supposed to have a doghouse, and not a left turn signal, in that situation.  Left turn signals should only be used for fully protected left turns, and those should be avoided wherever possible.

All of these problems could be avoided by ending the overuse of dedicated left turn signals.  Upstate NY gets it right: doghouses if a protected left turn phase is needed, left turn signal as a last resort only.

I believe you're confusing terminology here...  A "doghouse" is a type of left turn signal. The doghouse allows for protected-permitted left turns, whereas a 3-section all-arrow display (your standard left turn signal display) is only used for protected turns.

You seem very rigid on the use of doghouse displays versus a standard left turn signal. Maybe it works well in upstate NY and other places, but there are instances elsewhere where using a doghouse alone for controlling left turns either isn't feasible or can be confusing. The FYA display helps mitigate that.

[vdeane]

I believe you're confusing terminology here...  A "doghouse" is a type of left turn signal. The doghouse allows for protected-permitted left turns, whereas a 3-section all-arrow display (your standard left turn signal display) is only used for protected turns.

The 3-section all-arrow display is not standard here.  We don't do fully protected left turns very often, and that's the way it should be.

You seem very rigid on the use of doghouse displays versus a standard left turn signal. Maybe it works well in upstate NY and other places, but there are instances elsewhere where using a doghouse alone for controlling left turns either isn't feasible or can be confusing. The FYA display helps mitigate that.

I cannot think of any situation where a doghouse isn't feasible except fully protected left turns, which would not use a FYA, and it is in no way confusing.

[NE2]

Please read up on the left turn trap and why a doghouse doesn't solve it (unless you use a confusing green on the doghouse when other lights have a red ball): http://projects.kittelson.com/pplt/LearnAbout/Learn3.htm

[Mr_Northside]

http://projects.kittelson.com/pplt/LearnAbout/Learn3.htm

It seems the phasing/timing that allows for the "Left Turn Trap" is the true problem.  PennDOT (in my experience) is very good in avoiding such nonsense.

[NE2]

http://projects.kittelson.com/pplt/LearnAbout/Learn3.htm

It seems the phasing/timing that allows for the "Left Turn Trap" is the true problem.  PennDOT (in my experience) is very good in avoiding such nonsense.

You most likely pay for that in the form of excessive red arrows or badly-timed arterials. Lead-lag phasing is an integral part of a well-timed signal progession that lets drivers get a number of greens in a row.

[PHLBOS]

PA dislikes

1.  Use of STOP signs as speed control on non-PennDOT roads (a MUTCD no-no).  One road near me was once a PennDOT road but was stripped of its designation (SR 2016 IIRC along Franklin Ave. in Ridley Township, Delaware County) back ing the mid-to-late 90s so that the township could erect 3 (later 4) sets of STOP signs facing the main thoroughfare; one of them is even for a Dead-End road entrance.

2.  Speed limits of 15 mph for both side streets and school zones.

3.  Innaugural use of the now-infamous Clearview font.

likes

MA's use of paddle LGS'

[Brandon]

Please read up on the left turn trap and why a doghouse doesn't solve it (unless you use a confusing green on the doghouse when other lights have a red ball): http://projects.kittelson.com/pplt/LearnAbout/Learn3.htm

Easily avoidable by having both directions go yellow at the same time.  That's how InDOT, IDOT, MDOT, and WisDOT all do it when they use a leading left turn and a permissible left turn signal (be it a tower or doghouse).  The FYA is superfluous and unnecessary when the permissive phase is used correctly as the yellow trap never exists in the first place.

[NE2]

Easily avoidable by having both directions go yellow at the same time.  That's how InDOT, IDOT, MDOT, and WisDOT all do it when they use a leading left turn and a permissible left turn signal (be it a tower or doghouse).  The FYA is superfluous and unnecessary when the permissive phase is used correctly as the yellow trap never exists in the first place.

You most likely pay for that in the form of excessive red arrows or badly-timed arterials. Lead-lag phasing is an integral part of a well-timed signal progession that lets drivers get a number of greens in a row.

[national highway 1]

I kind of like Arizona's exit tabs, i.e. square corners with rounded borders:

[agentsteel53]

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

[mcdonaat]

Guess I'll put it here, and see if people agree - Louisiana has a laissez-faire approach to state shields. Some 3di and 4di roads are on a 30x24 shield with Series D, some 3di and 2di roads are on 24x24 with either Series D or C, and some are on a cartoonish version of the state. One contractor signed the entire LA 1 corridor with the 30x24 shields, except for one intersection, where the normal 24x24 is used. The state said that the contractors have the freedom to put up any shield they would like; that proved true, as a brand new green and white shield has been put up, with the Interstate state shield design (green and white with a widened generic outline), on a highway that doesn't even go anywhere near an Interstate.

Also, the signing of new routes with a new number instead of a spur of an old number.

[roadfro]

The state said that the contractors have the freedom to put up any shield they would like;

I sure hope that really isn't the case. LaDOT should have some uniformity and expect contractors to follow specs.

[Roadsguy]

PA dislikes
3.  Innaugural use of the now-infamous Clearview font.

Depends on where you go in the state, but yeah, PennDOT and the PTC both abuse Clearview. Philadelphia has lately been replacing their iconic blades with ugly mixed-case Clearview ones. They are the same shape, though. The worst are at the newly-two-way Cottman Ave/PA 73 near I-95, and on the Boulevard at the new pedestrian signals. Clearview 1s. >.<

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

[agentsteel53]

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? 

[Takumi]

other states replace signs with Clearview for no reason at all

*coughVDOTcough*

[vdeane]

Please read up on the left turn trap and why a doghouse doesn't solve it (unless you use a confusing green on the doghouse when other lights have a red ball): http://projects.kittelson.com/pplt/LearnAbout/Learn3.htm

Easily avoidable by having both directions go yellow at the same time.  That's how InDOT, IDOT, MDOT, and WisDOT all do it when they use a leading left turn and a permissible left turn signal (be it a tower or doghouse).  The FYA is superfluous and unnecessary when the permissive phase is used correctly as the yellow trap never exists in the first place.

Or adding an all-red phase.  Yellow does not mean "stop unless you can't".  It means "you can still go if you want, but I'm just warning you that the light will turn red soon, so be prepared for that".  As such, phases with yellow trap are just plain irresponsible and should get the engineers who designed them fired.

[agentsteel53]

wait, just to clarify... "yellow trap" means "vehicle intending to turn right and getting yellow assumes oncoming traffic also gets yellow and will roll to a stop"?  correct?

anyone getting yellow trapped has never driven in Los Angeles, where the correct and expected behavior on a yellow is to floor it.

[PHLBOS]

PA dislikes
3.  Innaugural use of the now-infamous Clearview font.

Depends on where you go in the state, but yeah, PennDOT and the PTC both abuse Clearview. Philadelphia has lately been replacing their iconic blades with ugly mixed-case Clearview ones. They are the same shape, though. The worst are at the newly-two-way Cottman Ave/PA 73 near I-95, and on the Boulevard at the new pedestrian signals. Clearview 1s. >.<

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

My point is that the Clearview font originated in PA roughly 7 to 8 years ago.

[kphoger]

Re:  yellow trap...

I always thought 'yellow trap' meant pulling into the intersection during a solid green phase with the intention of turning left, still being there when the light turns red, but being unable to clear the intersection due to oncoming traffic's still having a green light (and thereby becoming an obstacle to oncoming, left-turning traffic, as well as looking to any cop like you're running the red light).  In that situation, a flashing yellow left arrow would alert the driver that it's still OK to turn left, but only after yielding to oncoming traffic which still has a green light.

You might call these situations poor planning, but the fact remains that they exist in many locations; especially where there are stoplights in close proximity to a railroad crossing, stoplight phases can get complicated.  Requiring all stoplights with a yellow trap to change their timings is not a more reasonable solution than simply allowing a FYA to be used.

Re:  yellow lights...

In some states, a yellow light does indeed mean STOP.  By law.  Minnesota, I'm looking at you.

[NE2]

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.

Please read up on the left turn trap and why a doghouse doesn't solve it (unless you use a confusing green on the doghouse when other lights have a red ball): http://projects.kittelson.com/pplt/LearnAbout/Learn3.htm