What intersections do you think need them? Or which intersections do you think don't warrant having one?
This one is in dire need of one, imho.
http://www.youtube.com/watch?v=tcbhzisxHd4 (http://www.youtube.com/watch?v=tcbhzisxHd4)
Be well,
Bryant
The intersection of River Road and Knoll Road in my town certainly could use one, but it would tie up traffic too much. It would make it too congested, which is why I think they have avoided putting one there.
In Prince George County, VA:
VA 156 BUS/Prince George Dr at SR 646/Middle Rd
SR 630/Jefferson Park Rd at SR 646/Middle Rd
SR 630/Jefferson Park Rd at SR 1337/Crossings Blvd
VA 156 at SR 616/Laurel Spring Rd
VA 156 at SR 616/Pole Run Rd(to a lesser extent)
In Hopewell, VA:
S 6th Ave at LaPrade Ave
VA 10 at Hummel Ross Rd(there are plans to put one here)
In Petersburg, VA:
Graham Rd at ramp from I-95 South
In Colonial Heights, VA: Southpark Blvd at Southpark Cir(near VA 144)
Conduit Rd at Southpark Mall entrance
Southpark Blvd/W Roslyn Rd at ramps to/from I-95 South
Conduit Rd at E Westover Ave
Roundabouts work better than traffic signals up to a certain traffic volume, especially when there are a large number of conflicting vehicles (such as a large left-turn volume from one or more directions). At certain low volumes, you can just do a two-way or even four-way stop (or blinking light), which is cheaper and easier to navigate than a roundabout. At a certain range of high volumes, roundabout vs. traffic signal comes down to the actual expected traffic patterns and requires a traffic analysis.
SR 531:
25th Avenue
45 Road
E. Lake Goodwin Road/Lakewood Road
Quote from: ComputerGuy on May 04, 2009, 06:41:27 PM
SR 531:
25th Avenue
45 Road
E. Lake Goodwin Road/Lakewood Road
:confused: :confused: :confused:
Huh?
I was talking about the intersections on WA-531 that need traffic lights.
Quote from: froggieIMO, quite a few intersections which people think need traffic signals would work better with roundabouts instead...
I agree, but GDOT isn't currently doing multi-lane roundabouts.
Quote from: AlpsROADSRoundabouts work better than traffic signals up to a certain traffic volume, especially when there are a large number of conflicting vehicles (such as a large left-turn volume from one or more directions). At certain low volumes, you can just do a two-way or even four-way stop (or blinking light), which is cheaper and easier to navigate than a roundabout. At a certain range of high volumes, roundabout vs. traffic signal comes down to the actual expected traffic patterns and requires a traffic analysis.
Yeah, I contacted GDOT about a roundabout at Old National Highway (SR 279) and I-85/285, and they stated as much -- traffic lights can handle more traffic in certain situations, where roundabouts would breakdown, etc., etc.
Be well,
Bryant
Traffic lights can "handle more volume" if you have the lanes to handle the movements. At which point you probably have exceeded the amount of right-of-way a roundabout would require. Though in the case of a 6-lane road, a traffic signal is pretty much your only option anyway (though I have yet to see an upper ceiling for the capacity of a multi-lane roundabout, I can't imagine them operating well with more than 2 lanes).
Roundabouts only really work one two-lane highways, and sometimes on 4-lane highways, but not on 6-lane highways unless you want the craze of the Arc de Triomphe in Paris (http://maps.google.fr/maps?f=q&source=s_q&hl=nl&geocode=&q=Arc+de+Triomphe,+Paris&sll=48.863063,2.303739&sspn=0.009994,0.019312&ie=UTF8&ll=48.873614,2.295027&spn=0.002498,0.004828&t=h&z=18).
What I really do hate about roundabouts that they build it a lot on formerly uncontrolled intersections, so all traffic has to slow down, instead of only the minor street that intersects.
Bryant, how heavy is traffic on the side road you came off of?
P.S.: I think some intersections already with traffic lights need to be retimed.
P.P.S.: Where's I.C. in this thread?!
Quote from: MichaelBryant, how heavy is traffic on the side road you came off of?
I don't have exact numbers, but there is a lot of traffic that turns left and right onto the minor road (Old Bill Cook Road) from SR 279 (Old National Highway). There are two banks (Wachovia and Bank of America), a day care, a shopping plaza (Old National Village), a fast food restaurant (Checkers), and a school (Heritage E.S.) that use this road as one of their access points. During the day, there's a pretty good deal of traffic. At night, the traffic decreases, but there is still a fair amount of traffic.
There is another signal (Godby Road) about a 1/4 mile (?) north of this intersection, so it may cause a little bit of a jam; however, safety would be improved.
I went to a meeting at a local community center where some engineers were talking about ATMs, placing advance street name signage, illuminated traffic light-mounted street name signage and pedestrian crossing signals like were placed on Buford Highway (US 23/SR 13). So, maybe this intersection improvement will be included in their plan.
Be well,
Bryant
click here (http://www.dot.state.ga.us/statistics/TrafficData/Pages/TrafficCounts.aspx) for GDOT's traffic counts, note that all roads are represented as State Routes, also U.S. Highways and Interstate Highways.
I posted this video on YouTube last year and sent it to GDOT. An engineer called me, we talked, and he had the timing modified. The light on the minor streets (Convention Center Concourse/Conley Street) is still long, but isn't as long.
http://www.youtube.com/watch?v=sCpY9zFRfEE (http://www.youtube.com/watch?v=sCpY9zFRfEE)
Be well,
Bryant
I have to wonder if roundabouts are inferior to traffic signals in areas with heavy platooning, and if another coordinated traffic signal would work better. There are a few where you have to wait long enough for a gap that sometimes it seems a signal would be just as fast. Best example of this would be 40th Street at Sheridan Boulevard in Lincoln, Nebraska -which Google shows having a signal instead of the current roundabout - though that one would work better if people would signal when exiting
I used to live in a new suburban development, and the arterials were lined with single lane roundabouts, and they became jammed every rushhour, single lane roundabouts do not really work with traffic volumes over 10,000 - 15,000... (and they're still advertising that they work up to 20,000 AADT)
QuoteRoundabouts only really work one two-lane highways, and sometimes on 4-lane highways, but not on 6-lane highways unless you want the craze of the Arc de Triomphe in Paris
I would disagree with this statement. The intersection of Town Center Dr and Hualapai Way (http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=town+center+dr+and+hualapai+way+las+vegas+nv&sll=36.170031,-115.256882&sspn=0.192622,0.304871&ie=UTF8&ll=36.178538,-115.317669&spn=0.001505,0.002382&t=k&z=19) (both 6-lane arterials) in the Summerlin area of Las Vegas, NV works surprisingly well. The trick, though, is that the right hand lane for each entry is a separated right turn only lane.
San Angelo, Tx: Grape Creek Rd - N Chadbourne St
it's close to the San Angelo Colesium which gets busy during San Angelo Stampede Football season, Rodeo/Carnival, Lake View Basketball/Softball season, ect
Some lights should probably just revert to flashing at hours where traffic drops. Stamford, CT put a signal in a few years back at the entrance to a middle school and a library. But it still functions as a light even on Sunday, when there's no one in school and the library's closed. :pan:
And there are a couple of lights to office parks which stay blinking on Saturday and Sunday, so I know the city is capable of timing it to do that on the weekend.
Most of the lights in town do cut off to flashing from either 11 PM or midnight to 5 AM, though, so they're sane there.
Around here, many of the traffic lights in Nashville itself go to flasher after 11pm or midnight. But, I can't recall any outside the city in suburban and rural areas working that way.
Go figure. :confused:
I wish they'd install one at my high school's entrance... 1500 kids and several hundred staff members. I can get home faster on the bus than driving it takes so long to get out of the parking lot.
QuoteI wish they'd install one at my high school's entrance... 1500 kids and several hundred staff members. I can get home faster on the bus than driving it takes so long to get out of the parking lot.
Mine is only sightly less at about 1200 students and it takes 15 minutes for the parking lot to even be clear(and the congestion on SR 616/Laurel Spring Rd at VA 106 lasts even longer). My planned signals on VA 156 at SR 616 West/Laurel Spring Rd and at SR 616 East/Pole Run Rd are supposed to help to an extent(along with widening of VA 156 and SR 616/Laurel Spring Rd and the addition of left-turn lanes).
At my college, there is a traffic light that does more harm than good. It turns red for me, even when there are no cars coming! I don't think it has an underground sensor loop, though. I could go on and on about badly timed signals.
Well the problem is that my school's just down Woodland Rd. from Fox Hill Rd. (VA-169), and there's 4 lanes which are pretty busy during rush hour but dead otherwise (its the main feeder route into the HRBT from my area), and there are 3 entrances, 3 exits mornings, and 2 entrances, 4 exits afternoons, but not even a shared left turn lane on Woodland. It's just terrible...
http://maps.google.com/?ie=UTF8&ll=37.056179,-76.317848&spn=0.00613,0.009656&t=h&z=17 (http://maps.google.com/?ie=UTF8&ll=37.056179,-76.317848&spn=0.00613,0.009656&t=h&z=17)
Gluttening the country with too many traffic lights creates more red light running issues. The more lights you have, the more frustrated drivers get.
My local stretch of road gained three signals in the last 6 months. All of them serve neighborhood access roads and are not sequenced with one another. This creates frustration when traveling the mainline. This road is too wide for a roundabout, but I think using more u-turn lanes the way North Carolina does on U.S. 1 south of Cameron and U.S. 17 in Brunswick County may be a better way of handling some of these movements over installing a conventional traffic light.
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fwww.southeastroads.com%2Fnorth_carolina010%2Fus-017_nb_at_wire_rd.jpg&hash=c5aa2131afb8e487f4e821bae44a71a845e06bfa)
U-turn lanes would be a good idea, or if it's a congested area, do what Broward County does and use U-turn signals.
Interesting difference between the US and NL traffic lights seems to be that US traffic lights are often placed across the intersection, while the Dutch ones are always before the intersection.
The Dutch situation has it's pro's and con's, first, the traffic light before the intersection means there is like 15 - 20 meters (60 ft) less space for cars to wait. On the other hand, when the light turns green, and someone from another direction just crossed a red light, means the traffic has to drive like 1 - 2 seconds first before actually accessing the intersection, reducing the chance of a collision when the clearing time of the intersection is tight.
Well I would assume that American traffic lights are across the intersection so cars can stop right at the intersection and still have a good view of the signal. Though I've also noticed signals going diagonally across an intersection to save space... which can create a few visibility issues with the signals.
QuoteU-turn lanes would be a good idea, or if it's a congested area, do what Broward County does and use U-turn signals.
Exactly. I skimmed the U.S. 98 Corridor Management Report by Santa Rosa County, Florida and it indicates that there are 125 crossovers on the stretch of roadway through just that one county. Adding signals is all that they have done so far in dealing with the safety issues.
If and when they decide to six-lane the roadway, the narrow grass median that accommodates a one or two car queue will not exist and many more signals will have to be put in place. If u-turn lanes or some other innovative traffic concept is not implemented, it will be another U.S. 441 through Lake County with signal after signal, all not timed with one another...
In Michigan for the longest time we've has eagles (http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=Greenfield+Road+%26+Tireman+Avenue&sll=42.932296,-81.820679&sspn=2.384868,5.822754&ie=UTF8&ll=42.35117,-83.196609&spn=0,359.969101&z=16&iwloc=A&layer=c&cbll=42.351093,-83.196613&panoid=73TJiFLM7cwNOlBAg1LJGg&cbp=12,197.46,,0,0.33), but more recently we've been switching to these (http://maps.google.com/maps?f=q&source=s_q&hl=en&q=Orchard+Lake+RD.+%26+12+Mile+Rd,+Farmington+Hills,+Oakland,+Michigan+48334&sll=37.0625,-95.677068&sspn=41.139534,93.164063&ie=UTF8&cd=1&geocode=FRZ_iAIdngwI-w&split=0&ll=42.503585,-83.362627&spn=0,359.969101&z=16&iwloc=A&layer=c&cbll=42.498969,-83.358566&panoid=KNQniKeb8EfeZ7T6lArjmQ&cbp=12,348.04,,0,-1.26).
Also, how do you post street view images?
Quote from: Hellfighter06 on May 24, 2009, 02:37:27 PM
Also, how do you post street view images?
I simply copy+paste it into paint, and then save it as a jpg, and then upload it to tinypic or imageshack or some other image hosting site.
^^ On Google Maps, move the little orange man to the map. After that, click on the link button and then highlight the html link ("Paste link in email or IM"). That way, you'll be able to view the streetview, without having to use MS Paint. Just found that out recently.
Be well,
Bryant
Quote from: Bryant5493 on May 24, 2009, 03:10:40 PM
^^ On Google Maps, move the little orange man to the map. After that, click on the link button and then highlight the html link ("Paste link in email or IM"). That way, you'll be able to view the streetview, without having to use MS Paint. Just found that out recently.
What I actually was asking was is there any way to post the scene without making a link, like posting an image.
To do that you would need to print screen, save the image, and upload it to a hosting site such as imageshack.
And for the record, you posted your reply withing the quote. ;)
Quote from: deathtopumpkins on May 24, 2009, 09:45:13 PM
And for the record, you posted your reply withing the quote. ;)
What quote?
The one you edited it to fix. :colorful:
Quote from: MichaelP.S.S. Where is I.C. in this thread?!
Alright, I guess I'll take part in this. I din't want to since it didn't really have to do with traffic signals themselves rather than the intersections ;-). But I guess I can think of a few intersections.
-PA 252/Sawmill Rd in Newtown Square, PA. Getting onto PA 252 from Sawmill Rd is a complete nightmare. You'll be sitting at the stop sign at a minimum of like 5 minutes. It is that bad.
-Lang Rd (NH 109)/Tuftonboro Rd (NH 28)/Center St (NH 28-109) in Wolfeboro, NH. The intersection is in the middle of the lakefront town of Wolfeboro on Lake Winnepesaukee in New Hampshire. All it has is just one hanging 3 way flasher with one way getting a stop sign. During the winter, Wolfeboro is like a ghost town, but during the summer its PACKED. When summer comes around, the intersection is a total nightmare. Basically its like an intersection in the heart of New York City.
-NH 16-113/W. Main Street in Conway, NH. Conway is a really major mountain town in the middle of the White Mountains in New Hampshire. The intersection only has a flashing beacon and at a lot of times, it gets extremely crowded at that intersection plus the rest of the town.
These are the only places I can think of that need traffic signals that I know of.
There was also an intersection by me that was recently upgraded with a traffic signal not too long ago that badly needed it. Its kind of dangerous though because it is on a hill but I'm glad there is finally a signal there. Here is a pic of it:
http://picasaweb.google.com/Iansignal/PennsylvaniaTrafficSignalsAndRoadSigns#5338843580510065090 All that used to be there was a single flasher beacon.
Going back to roundabouts and traffic circles, you gotta think of where you are putting them. What I mean is that if you put a traffic circle in an area where they are not used to them, drivers going through them are going to know nothing about what to do when going through it. For example, Pennsylvania barely has ANY traffic circles. Just a few months ago, there was a new traffic circle that replaced a stop sign at the intersection of St. Davids Rd and Newtown St Rd in Newtown Square, PA. I went to go see what it looked like and I noticed that the drivers were totally oblivious to what they were doing when going through the circle. Goes to show that its better installing traffic circles in places where they are used to them like New York, New Jersey, or Massachusetts.
-i
Quote from: PennDOTFan on May 25, 2009, 05:26:02 PM
Going back to roundabouts and traffic circles, you gotta think of where you are putting them. What I mean is that if you put a traffic circle in an area where they are not used to them, drivers going through them are going to know nothing about what to do when going through it. For example, Pennsylvania barely has ANY traffic circles. Just a few months ago, there was a new traffic circle that replaced a stop sign at the intersection of St. Davids Rd and Newtown St Rd in Newtown Square, PA. I went to go see what it looked like and I noticed that the drivers were totally oblivious to what they were doing when going through the circle. Goes to show that its better installing traffic circles in places where they are used to them like New York, New Jersey, or Massachusetts.
I kind of like the idea of roundabouts in urban areas since they cut out waiting for stoplights. What baffles me is KDOT's pastime of randomly plunking them down in the sticks at godforsaken highway intersections. I encountered one around Garnett after driving across nearly the entire length of US 169 from the Oklahoma border to that point, and, not expecting it, nearly went over the island.
An updated video.
http://www.youtube.com/watch?v=8nn-x50J-NM (http://www.youtube.com/watch?v=8nn-x50J-NM)
Be well,
Bryant
Texas I think is a little too traffic signal happy if you ask me. I've noticed that lights in Texas seem to hold longer than most states. Lights at freeways (thanks to Frontage roads) hold forever. My least favorite is a light near my house at the intersection of TX-99 (Grand Parkway) and Westpark Tollway. That light will hold you for five minutes. And TX-99 hasn't been upgraded to limited access at that intersection yet, so you have no choice but to sit through it.
Here's an example of our new left-turn signal
http://www.youtube.com/watch?v=O-h7bPSAd1A
Quote from: Hellfighter on September 07, 2009, 11:31:30 PM
Here's an example of our new left-turn signal
I saw several of these a few weeks ago in San Antonio. I thought it was just something they were doing locally there. But I guess not.
Flashing Yellow Arrows started showing up here in Ft Smith about 2 years ago. Initially, there were only 5 or 6. Now, many new intersections with dedicated left turn lanes are receiving the signals and many existing intersections are being retrofitted.
Quote from: Marc on September 08, 2009, 12:11:37 AM
Quote from: Hellfighter on September 07, 2009, 11:31:30 PM
Here's an example of our new left-turn signal
I saw several of these a few weeks ago in San Antonio. I thought it was just something they were doing locally there. But I guess not.
Nope, the flashing yellow arrow is in use in quite a few places now. It has moved beyond experimental stage and now has interim approval; it will be the suggested method for controlling protected-permitted left turns in the next MUTCD (as opposed to the 5-section heads).
We've discussed it's use previously in other threads.
Is there any signage around the intersection to let drivers unfamiliar with this type of traffic light function know how to approach and utlize the signal?
Unrelated Note: Also, I've been confronted with several differing methods to approaching an intersection that has flashing yellow on two segements and flashing red on the other two legs -- treat it as an all-way stop. The other is to proceed with caution with the flashing yellows, which I think is correct. Also, I know that a totally blacked-out intersection is an all-way stop.
Be well,
Bryant
Quote from: Bryant5493 on September 08, 2009, 09:07:32 PM
Is there any signage around the intersection to let drivers unfamiliar with this type of traffic light function know how to approach and utlize the signal?
Generally, no. One of the things studied during the flashing yellow arrow research was various drivers' reactions upon seeing various left turn control types. One of the reasons for adopting this design was that drivers generally understood the meaning intuitively without additional explanatory signage.
Quote from: Bryant5493 on September 08, 2009, 09:07:32 PM
Unrelated Note: Also, I've been confronted with several differing methods to approaching an intersection that has flashing yellow on two segements and flashing red on the other two legs -- treat it as an all-way stop. The other is to proceed with caution with the flashing yellows, which I think is correct.
The only times a signal is treated as an all-way stop is if it is dark or if it is flashing red in all directions (assuming there are no other controls, such as police/flaggers directing traffic).
If a signal is operating in a red/yellow flash mode and you are approaching from the flashing red side, you must treat it as if you were approaching a stop sign. If you are approaching on a leg with flashing yellow, you should slow down and proceed with caution, yielding right of way to any vehicles which are already lawfully in the intersection.
Quote from: Bryant5493
Is there any signage around the intersection to let drivers unfamiliar with this type of traffic light function know how to approach and utlize the signal?
Quote from: roadfro
Generally, no. One of the things studied during the flashing yellow arrow research was various drivers' reactions upon seeing various left turn control types. One of the reasons for adopting this design was that drivers generally understood the meaning intuitively without additional explanatory signage.
Okay, thanks.
Quote from: Bryant5493
Unrelated Note: Also, I've been confronted with several differing methods to approaching an intersection that has flashing yellow on two segements and flashing red on the other two legs -- treat it as an all-way stop. The other is to proceed with caution with the flashing yellows, which I think is correct.
Quote from: roadfro
The only times a signal is treated as an all-way stop is if it is dark or if it is flashing red in all directions (assuming there are no other controls, such as police/flaggers directing traffic).
If a signal is operating in a red/yellow flash mode and you are approaching from the flashing red side, you must treat it as if you were approaching a stop sign. If you are approaching on a leg with flashing yellow, you should slow down and proceed with caution, yielding right of way to any vehicles which are already lawfully in the intersection.
That's what I thought and pretty much knew, but I see folks stopping on flashing yellows, so I, in turn, follow suit when a light's malfunctioning. Not all of the time, but on a wide heavily congested road.
*EDIT* Additionally, traffic reporters confuse matters with the way that they explain what to do in situations such as these. But the driver's manual does spell it out clearly. (Something nobody reads. :-D)
Be well,
Bryant
Quote from: Bryant5493
QuoteIs there any signage around the intersection to let drivers unfamiliar with this type of traffic light function know how to approach and utlize the signal?
The only signage I've seen is similar to the "Left Turn Yield on Green" signs, but with the legend "Left Turn Yield on Flashing
(<-- ) "
I really need a photo of one of those signs
Flashing yellows have been showing up all over Washington County, Oregon over the past couple years. The one at OR-10 (Beaverton-Hillsdale Hwy)/SW 110th Ave in Beaverton was one of the "pilot" ones, as I recall. ODOT's gotten fully on board with flashing yellow signals, and a recent technical document they published on signals stated that the 5-light "doghouse" setup was no longer to be used.
Washington County's Department of Land Use and Transportation (LUT) has also gone around eliminating a number of fully-protected left turn signals and replacing them with flashing yellows as well. I'm not really sure how I feel about that yet.
-Alex (Tarkus)
These new flashing yellow signals haven't shown up in Phoenix yet; at least I've not seen any.
Norman appears committed to the five-light doghouse signal. They're everywhere.
Haven't seen a FYA in Oklahoma at all yet.
On the subject of Flashing Yellow Arrows, I've noticed recently that Andrews AFB has a temporary Flashing Yellow RIGHT Arrow at an intersection, due to construction.
Not the first one in the region, though...there's a Flashing Yellow Right Arrow on Virginia Ave NW near the Watergate (yes, that Watergate).
Several Flashing Yellow Left Arrows in Alexandria, mainly along Duke St (VA 236), but also one on Washington St (VA 400/Hidden VA 90005).
I don't know how the city of Boston screens its traffic engineers, but they must not require any sort of expertise, because this city is the worst I've ever seen. It's usually not an issue of not having traffic signals where they're needed, but the city is at least 50 years behind the times in installing pavement sensors to trigger the signals. Every day on my commute I deal with at least half a dozen signals which turn red for the main road with no traffic whatsover waiting on the side street. Operating traffic signals on timers in that situation is so 1960.
Those are static traffic lights, they do the same cycle over and over again. They may be time programmed, but are fairly insufficient these days.
Quote from: SidS1045 on September 11, 2009, 09:43:10 AM
I don't know how the city of Boston screens its traffic engineers, but they must not require any sort of expertise, because this city is the worst I've ever seen. It's usually not an issue of not having traffic signals where they're needed, but the city is at least 50 years behind the times in installing pavement sensors to trigger the signals. Every day on my commute I deal with at least half a dozen signals which turn red for the main road with no traffic whatsover waiting on the side street. Operating traffic signals on timers in that situation is so 1960.
if you don't run 3 red lights each way on your commute, you're not truly driving in Boston!
I've noticed that problem around here too, but the lights seem to be affected by traffic levels, so I assume that there is some sort of sensor. Many entrances to now-dead shopping centers that are like this seem to change periodically just to go through the cycle. Nonexistent cross-traffic only has a green for a few seconds, while through traffic has it for several minutes.
As for flashing yellow arrows, I noticed a few of them on US-158 on the Outer Banks installed this summer, and might have a pic lying around somewhere.
What do you do on a yellow arrow? Yield to oncoming traffic when turning?
Quote from: deathtopumpkins on September 11, 2009, 11:41:58 PM
What do you do on a yellow arrow? Yield to oncoming traffic when turning?
Yes, that's it exactly. The flashing yellow arrow means the same thing as a doghouse with a green light but no green arrow.
-Alex (Tarkus)
That'd better be in the new MUTCD & some updated driving manuals, because that's gonna confuse a lot of people.
Quote from: burgess87 on September 14, 2009, 09:01:13 AM
That'd better be in the new MUTCD & some updated driving manuals, because that's gonna confuse a lot of people.
Given how much most people actually read these days, it will confuse a lot of people even if it's in the MUTCD and updated driving manuals. :banghead:
Quote from: burgess87 on September 14, 2009, 09:01:13 AM
That'd better be in the new MUTCD & some updated driving manuals, because that's gonna confuse a lot of people.
The meaning of a flashing yellow indication is already in the MUTCD Section 4D.04 (http://mutcd.fhwa.dot.gov/htm/2003r1r2/part4/part4d.htm#section4D04)
Quote from: MUTCD Section 4D.04
Standard:
The following meanings shall be given to highway traffic signal indications for vehicles and pedestrians:
(...)
D. Flashing signal indications shall have the following meanings:
1. Flashing yellow–When a yellow lens is illuminated with rapid intermittent flashes, vehicular traffic is permitted to proceed through the intersection or past such signal indication only with caution.
(...)
3. Flashing RED ARROW and flashing YELLOW ARROW signal indications have the same meaning as the corresponding flashing circular signal indication, except that they apply only to vehicular traffic intending to make the movement indicated by the arrow.
However, the meaning of a flashing yellow arrow as it relates to turns is not fully made clear from these definitions--especially as it relates to yielding to oncoming traffic or pedestrians. The current definition of circular green does a better job
Quote from: MUTCD Section 4D.04
Standard:
The following meanings shall be given to highway traffic signal indications for vehicles and pedestrians:
(...)
A. Steady green signal indications shall have the following meanings:
1. Traffic, except pedestrians, facing a CIRCULAR GREEN signal indication is permitted to proceed straight through or turn right or left except as such movement is modified by lane-use signs, turn prohibition signs, lane markings, or roadway design. But vehicular traffic, including vehicles turning right or left, shall yield the right-of-way to other vehicles, and to pedestrians lawfully within the intersection or an adjacent crosswalk, at the time such signal indication is exhibited.
It should be noted that the new version of the MUTCD has a proposed text revision that aligns the meaning of a flashing yellow arrow to that of the yield-when-turning condition of the circular green.
It's also shown in the 2007 MUTCD Figures Notice of Proposed Amendments, as Figure 4D-12.
ODOT's also got them codified in their "Traffic Signal Policy and Guidelines (http://www.oregon.gov/ODOT/HWY/TRAFFIC-ROADWAY/docs/pdf/Traffic_Signal_Policy_and_Guidelines.pdf)" document--see Figure E1 (page 63 of the PDF). If you'll scroll down, you'll notice that Figure E2 (the "doghouse") comes with the warning "Not acceptable for new designs on state highways". (Farther up in the document, they say that there are limited exceptions, but it's pretty clear they're "gung ho" on Flashing Yellows.)
The 2007-2009 Oregon Drivers' Manual (http://www.odot.state.or.us/forms/dmv/37.pdf) also describes Flashing Yellow lights on the section about protected/permitted signals (pages 22-23), but the illustration of a protected/permitted signal that they show is of a doghouse. I presume they'll be fixing that in the 2010 edition--especially since there's 188 of them (http://www.oregon.gov/ODOT/HWY/TRAFFIC-ROADWAY/docs/pdf/FYA.pdf) in operation as of August 6th, 2009.
-Alex (Tarkus)