Blinking yellow turn arrows (Dallas, San Antonio: dangerous, safe, suburb)

[cr1039]

I have noticed these along Wurzbach.

They are truly awful, instead of a solid green light - letting those who need to make a left turn know that they are able to go but are not protected - a blinking yellow arrow has taken it's place.

I have seen a few near accidents because I think that people think they are able to turn, as if on a yellow light, and the oncoming cars are coming to a stop at the intersection.

What I don't understand is, is this now an actual traffic signal - being taught in Driver's Ed and all?

I did not hear a word about it and again, think it is ridiculous.

[Bo]

It was in the news when this was introduced last month. It's a pilot program in SA that research has shown reduces accidents when it was used in other cities.

City Introduces Pilot Program For New Traffic Signals - Automotive News Story - KSAT San Antonio (http://www.ksat.com/automotive/17966149/detail.html?rss=ant&psp=news - broken link)

MySanAntonio.com Mobile Edition

SA Motorists Will See Something New at Some City Traffic Signals | WOAI.COM: San Antonio News

[smuboy86]

They are also using it in the Dallas suburb of Richardson. New yield on yellow blink signs also went up. I haven't seen any increase in accidents at the intersections that I go through every day due to the new turn signals.

[scuba steve]

They're awesome - I hate the red turn arrows that are all over this town. I can't think of all the times I've been stuck at a light, green light for going straight and a red to take a left where I can see way out to the horizon... no oncoming traffic. Completely safe to turn but no, you're not allowed to look ahead, think, and take a perfectly safe left turn.

I hope more of these things show up, at least on roads I travel on.

[cr1039]

Oh goodness, could not disagree more. I really don't like the yellow blinking turn lights.

Perhaps I am just so used to a solid green light in the turn lane meaning "unprotected left turn".

In other situations, when going straight, if you have a solid yellow light - that means the light will turn red soon so one would know that any car that is opposite of yours is coming to a stop at the intersection.

What I saw this morning was three cars ahead of me take the turn and a 4th car that then tried to - assuming that the oncoming traffic was not going to cross the intersection.

I think it is dangerous but what better place than SA to pilot it - where driver's pay no mind anyway

[TexHwyMan]

Originally Posted by cr1039

Oh goodness, could not disagree more. I really don't like the yellow blinking turn lights.

You are in a small minority. History showed that the circular green signal for a permissive left turn ("permissive" in traffic lingo means that a maneuver allowed but drivers making that maneuver must yield) resulted in driver confusion, so a study was done to determine the best new national standard signal for a permissive left. Here is a summary of that study; I've highlighted the key findings in bold red:

Traffic engineers around the country had implemented a variety of unique permissive only left-turn signal indications in an attempt to better communicate to the left-turn driver that they must yield to opposing through traffic before turning. It was perceived that drivers did not adequately comprehend the predominant permissive only display in use, the circular green (CG) permissive only left-turn indication, because of increases in left-turn crashes and decreases in operational efficiency. Therefore, a number of unique permissive only left turn indications were implemented in an attempt to resolve the problem including the flashing red arrow (FRA), flashing circular red (FCR), flashing yellow arrow (FYA), and flashing circular yellow (FCY). Research was needed to evaluate each of these and determine which was most effective and could be uniformly applied throughout the United States (U.S.). To complete this research, a comprehensive array of research studies and experiments were completed including driver behavior laboratory analyses, operational and behavioral field evaluations, and full-scale driving simulator analyses.

NCHRP Report 493 recommended the use of a flashing yellow arrow indication as the desired permissive only indication when using protected/permissive left-turn (PPLT) signal phasing. The report cited that the flashing yellow arrow had a high level of driver comprehension, overcame many of the human factors issues with permissive only left-turns, and was shown to have the most versatile characteristics of all the permissive only displays studied. Furthermore, the FYA had an important safety characteristic; drivers who did not understand the meaning of the FYA tended to yield, which is a desirable failure outcome. This was in contrast to drivers who did not understand the meaning of the CG, in which case drivers tended to assume right-of-way and go, a very undesirable outcome.

The source of the quote above is a more recent report that evaluted the safety of the FYA in various implementations. The report concluded that in cases where there previously was a protected/permissive phase using the CG permissive left signal, safety was indeed improved. In cases where there was previously a protected-only left turn signal, there was no immediate safety improvement, although this was attributed to the change from protected-only to protected-permissive rather than the change in display, and safety at those intersections did improve over time. There was inconclusive data for intersections that were previously permissive-only. Overall, the report showed that safety was improved at intersections that used a FYA.

This is not a San Antonio thing. This was a national study and the signal has been approved for national use. Google "flashing yellow arrow" and you'll see it's being used in many places, including Oregon, Michigan, Washington state, and Charlotte, just to mention a few. Another type of permissive left turn phasing being evaluated by the City of San Antonio is something called "Dallas phasing", which is being tested at various intersections in the Medical Center. This uses the same phasing techniques the the FYA intersections do, namely that the permissive left turn can be shown even when the adjacent through traffic has a red. But with Dallas phasing, the CG signal is used to indicate the permissive turn. To prevent the adjacent through traffic from seeing the circular green signal and thinking they can go, the left turn signal is fitted with louvers so that it is only visible to left-turning traffic. I have seen many accidents and near-accidents resulting from this signal configuration because the left-turning drivers see the green signal and think it is protected, even through there is a sign saying "LEFT TURN YIELD ON GREEN O". Meanwhile, I also drive a section of Wurzbach twice a day (sometime 4x a day) that has FYA signals and I have not seen any problems. Everyone I've seen seems to intuitively recognize that the signal indicates a need to use caution and yield if making a left turn.

FWIW, the FYA is also used in Germany and other areas of Europe as the permissive left turn signal.

[ShaneSA]

Have I been in a cave?
Today I saw 2 places with left turn arrows that at first were green arrows and then they began to flash yellow arrows.
Apparently, instead of only a green arrow to turn left, you can also turn on a yellow arrow, after yielding to oncoming traffic. I haven't seen this before.
It's a good idea, no more waiting for only the green arrow.

[LindaGrace]

I saw them first maybe 5 or 6 weeks ago. Freaked me out.

[Eleanor Rigby]

I saw these a few days ago...I actually sat there for a second trying to figure out what they mean, before someone started honking angrily at me. It's a clever idea.

[ShaneSA]

I too sat there staring at it trying to figure it out. I need to get out more if it's been around for 5 or 6 weeks. At least now I know and a few others who have not seen it who read this will know.