Traffic signal

[jakeroot]

Saw this earlier today in this video. Is Caltrans adding yellow reflective tape on their new signal installations, or is this a just a city/town decision?

Redwood City near YouTube headquarters

I've been seeing it sparingly, but doesn't appear to be coming from Caltrans. Other intersections nearby (that were also recently updated) have them too.

For the record, Youtube's headquarters are in San Bruno (indeed near this intersection), not Redwood City.

Oops my bad, meant to type San Bruno instead of Redwood City - running on little sleep this week!

The one on that Youtube video is at 4:50. It is in St Helena CA at this intersection. For some reason, they decided to keep the 8 inch (200 mm) signals. Wonder if that is a new installation, or if they just slapped on some reflective tape on the signals and kept the existing configuration like what some signals in New Hampshire are doing.

All good! Not like Redwood City isn't known for being the headquarters for other groups as well.

For the record, I'm not able to watch the video. "Bad Drivers of [Napa Valley]" banned me years ago. I told him he was a shit driver a while ago, and that his videos were boring for including stuff that everyone does all the time.

[jakeroot]

I think this is a decent-enough place to post this.

City of Tacoma recently installed a new RRFB outside Annie Wright School to better facilitate the heavy crossings that occur in this area during peak hours; it replaced(?) a permanent flashing beacon, of which I'm not a fan but which proliferate throughout Tacoma (and are probably the most common type of crossing). This RRFB was installed maybe six months ago, but the original beacon is still posted overhead and continues to flash.

Is it OK to combine RRFBs with permanent-flashing beacons? Or no? Part of me doesn't actually mind it, as it continues to remind passing drives that this is a crosswalk, so when it goes into rapid-flashing mode, drivers might be more prepared to stop.

There is nothing in FHWA's Interim Approval 21 document prohibiting a continuously flashing beacon from operating above a crosswalk with RRFBs in this manner. However, part of the draw for installing RRFBs is that it is a pedestrian-activated warning device which is only going to flash when the warning condition is relevant ("hey, a pedestrian is crossing right now"). Contrast this to a continuously-flashing beacon ("hey, there could maybe be a pedestrian here").

I believe there are studies out that show continuously-flashing beacons at crosswalks lose effectiveness over time because drivers get used to the beacon warning of a condition that is not always present. So from that perspective, I don't think a continuously-flashing beacon should be used in conjunction with RRFBs–if the crosswalk/school crossing signs and pavement markings aren't enough to indicate the crosswalk exists, an overhead beacon isn't going to help much more. The RRFB flash pattern is incredibly attention-grabbing by itself, which (at least in my experience) invokes a high driver yield rate.

I can understand the lack of effectiveness. I suspect that those around schools are fairly well observed, due to the sheer number of regular crossings, but those that are in seemingly-random locations with even more random pedestrian arrivals are probably less effective due to the constantly-flashing beacon.

I did not test the effectiveness of the crosswalk without hitting the RRFB; as someone who walks almost more than I drive, it's hard for me to wait at a crossing for cars to stop. 99% of the time, I find a gap and dash through it. But one of these days, I'm going back to that crossing and will be doing some field testing on how long takes for me to stand there before someone stops without hitting the RRFB button.

One thing I'm not totally keen on, and which can be seen in my photo, is the placement of the new post-mounted crossing signs. These are lovely, of course, but I wish they were placed further back from the road. Right now, drivers approaching the crosswalk may not be able to see a smaller person behind the pole on their side of the street.

[Rothman]

Isn't there a large Oracle complex near or in Redwood City?  Used to be when I lived in San Mateo.

[roadfro]

I think this is a decent-enough place to post this.

City of Tacoma recently installed a new RRFB outside Annie Wright School to better facilitate the heavy crossings that occur in this area during peak hours; it replaced(?) a permanent flashing beacon, of which I'm not a fan but which proliferate throughout Tacoma (and are probably the most common type of crossing). This RRFB was installed maybe six months ago, but the original beacon is still posted overhead and continues to flash.

Is it OK to combine RRFBs with permanent-flashing beacons? Or no? Part of me doesn't actually mind it, as it continues to remind passing drives that this is a crosswalk, so when it goes into rapid-flashing mode, drivers might be more prepared to stop.

There is nothing in FHWA's Interim Approval 21 document prohibiting a continuously flashing beacon from operating above a crosswalk with RRFBs in this manner. However, part of the draw for installing RRFBs is that it is a pedestrian-activated warning device which is only going to flash when the warning condition is relevant ("hey, a pedestrian is crossing right now"). Contrast this to a continuously-flashing beacon ("hey, there could maybe be a pedestrian here").

I believe there are studies out that show continuously-flashing beacons at crosswalks lose effectiveness over time because drivers get used to the beacon warning of a condition that is not always present. So from that perspective, I don't think a continuously-flashing beacon should be used in conjunction with RRFBs–if the crosswalk/school crossing signs and pavement markings aren't enough to indicate the crosswalk exists, an overhead beacon isn't going to help much more. The RRFB flash pattern is incredibly attention-grabbing by itself, which (at least in my experience) invokes a high driver yield rate.

I can understand the lack of effectiveness. I suspect that those around schools are fairly well observed, due to the sheer number of regular crossings, but those that are in seemingly-random locations with even more random pedestrian arrivals are probably less effective due to the constantly-flashing beacon.

I did not test the effectiveness of the crosswalk without hitting the RRFB; as someone who walks almost more than I drive, it's hard for me to wait at a crossing for cars to stop. 99% of the time, I find a gap and dash through it. But one of these days, I'm going back to that crossing and will be doing some field testing on how long takes for me to stand there before someone stops without hitting the RRFB button.

One thing I'm not totally keen on, and which can be seen in my photo, is the placement of the new post-mounted crossing signs. These are lovely, of course, but I wish they were placed further back from the road. Right now, drivers approaching the crosswalk may not be able to see a smaller person behind the pole on their side of the street.

Looking at the photo again and confirming with your street view link, it appears that this crosswalk was reconstructed with pedestrian bulb-outs. Having the crosswalk signs closer to the road helps increase the visibility of the crosswalk (which was one of your concerns), especially as there appears to be on-street parking on both sides of the road. Since the signposts also typically incorporate the actuation button, having the posts closer to the road minimizes the distance between the button and the actual crosswalk (which in turn allows the RRFB flash time to be shorter). But I don't think these posts are so thick that a kid would be completely hidden by them.

Speaking of the buttons: It appears the sign on the left does not have an actuation button, but the right side does. Odd...perhaps the installation wasn't finished yet at time of photo?

[jakeroot]

Looking at the photo again and confirming with your street view link, it appears that this crosswalk was reconstructed with pedestrian bulb-outs. Having the crosswalk signs closer to the road helps increase the visibility of the crosswalk (which was one of your concerns), especially as there appears to be on-street parking on both sides of the road. Since the signposts also typically incorporate the actuation button, having the posts closer to the road minimizes the distance between the button and the actual crosswalk (which in turn allows the RRFB flash time to be shorter). But I don't think these posts are so thick that a kid would be completely hidden by them.

Speaking of the buttons: It appears the sign on the left does not have an actuation button, but the right side does. Odd...perhaps the installation wasn't finished yet at time of photo?

I'm definitely for the bulb-outs, but I thought it was odd that the sign-posts weren't situated on the opposite sides of the curb ramp. I suppose it's a minor thing, but it was something I noticed.

The activation button is just out of view on the left. I have no idea why they decided to place it there.

Isn't there a large Oracle complex near or in Redwood City?  Used to be when I lived in San Mateo.

Huge, yeah.

[fwydriver405]

Does anyone have a clue why some intersections near Greater Boston use 4 section signals that look like they could be used for FYA when they are really only used for protected only phasing? These signals have been around before MA converted to FYA. This isn't to be confused with the new FYA signals that have popped up in Massachusetts statewide. These signals are RA-Y-YA-GA. The RA and GA are used like an FYA, but the SYA is where the FYA is and the spot where the SYA is isn't used. In fact, one intersection (marked with an *) I thought was a double protected/permissive left but it's really not.

Middlesex Tpke at 128 South* in Burlington MA
Middlesex Tpke at Burlington Mall in Burlington MA
Middlesex Tpke at Burlington Mall Rd in Burlington MA
Middlesex Tpke at Wheeler Rd in Burlington MA
Route 28 at William St in Burlington MA. You can see the yellow ball and arrow light up at the same time.

[roadfro]

^ My only guess is that they reused hardware from a previous installation or setup. Doesn't make sense otherwise, especially with two yellow indications in a protected-only phasing scheme.

[Amtrakprod]

Does anyone have a clue why some intersections near Greater Boston use 4 section signals that look like they could be used for FYA when they are really only used for protected only phasing? These signals have been around before MA converted to FYA. This isn't to be confused with the new FYA signals that have popped up in Massachusetts statewide. These signals are RA-Y-YA-GA. The RA and GA are used like an FYA, but the SYA is where the FYA is and the spot where the SYA is isn't used. In fact, one intersection (marked with an *) I thought was a double protected/permissive left but it's really not.

Middlesex Tpke at 128 South* in Burlington MA
Middlesex Tpke at Burlington Mall in Burlington MA
Middlesex Tpke at Burlington Mall Rd in Burlington MA
Middlesex Tpke at Wheeler Rd in Burlington MA
Route 28 at William St in Burlington MA. You can see the yellow ball and arrow light up at the same time.

These are so common everywhere. In my town they show the yellow ball and yellow arrow at the same time. In other spots it's just the yellow arrow lighting up. One spot was a 4 section with RB RA YA GA, and the red ball lighted up when the crosswalk was on.


iPhone

[jakeroot]

In Richmond, BC, the yellow arrow and yellow orb come on at the same time. This occurs at three-section protected-only signals; the bottom arrow is a bimodal green/yellow arrow, and the other indications are orbs.

[mrsman]

But why do New Hampshire traffic engineers even bother posting that sign next to a red left-turn arrow? It's not required by the Manual, and it's not needed. So in this case by posting an unnecessary/redundant sign, they outsmarted themselves and caused more confusion.

I've never understood this practice, and it's various equivalents (such as "LEFT ON LEFT/GREEN ARROW ONLY"). Left from two-way to two-way is prohibited on red in every state; the only time they make sense is in WA/OR/MI where left turns onto one-way streets are OK on red arrows (example of prohibition in Clark County, WA).

The only case for any supplemental signage (IMO) might be when the signal does not use red arrows. This practice isn't permitted anymore, so examples of this should be dwindling.

When signals at our new high school in Sanford ME were being designed, the signal configuration had protected-only left turns on the leading leg, and PPLT on the lagging leg. Although the sign was never installed, one traffic engineer told me that they were planning to put a "NO TURN ON RED ARROW" sign on the protected only-side entering the high school. The reason was to remind drivers about that turn into the high school being protected-only as the opposing direction had PPLT, which may result in drivers on the protected-only side being confused about why they can't proceed.

what intersection in Sanford is this?


iPhone

Main St and Old Mill Rd / Alumni Blvd. These signals were installed early January 2019 and activated on 26 Feb 2019. Google Maps doesn't have an up to date image so here is what the signals look like as of 15 March 2019 (still current as of today):


Intersection Phasing (sequential lead-lag)

The doghouse on the left will be replaced with a(n) FYA when Sanford replaces their traffic signals in 2020-2022.

EDIT: This is where the "NO TURN ON RED ARROW" sign was mentioned. City Council Meeting March 20, 2018. Skip to 47:35 for the signage explanation. 24:18 is where the entirety of the project begins.

Of course, having the lead signal protected left only is designed to prevent yellow trap.  the sign just reinforces it.

Yes, the sign is technically unnecessary with the red arrow signal, but we really don't want the cars here turning at any other time than green arrow.

[jakeroot]

Definitely haven't seen a mast-mounted signal configured this way.

Division & I Sts, Tacoma, WA

[SignBridge]

That's called a plumbizer mount and is standard in California and probably other Southwestern states.

[jakeroot]

That's called a plumbizer mount and is standard in California and probably other Southwestern states.

I don't know if that's right. Most pole-mounted signals that I've seen in California use some kind of split-arm mounting mechanism, like this. This is also the norm in WA (this is two blocks up from the image above), but this is an odd one from what I've seen.

Overhead signals are very often mounted using a plumbizer, but I don't believe it to be the standard for pole-/mast-mounted signals.

[SignBridge]

It's possible that older pole-plumbizer mounts have been replaced with the style in your photos. In fact the first one I ever noticed in Walnut Creek, Calif. in the mid-1990's had been replaced by 2010. Also the one in your first photo in Tacoma, Wa. looks like an old one, with its faded green paint.

[jakeroot]

It's possible that older pole-plumbizer mounts have been replaced with the style in your photos. In fact the first one I ever noticed in Walnut Creek, Calif. in the mid-1990's had been replaced by 2010. Also the one in your first photo in Tacoma, Wa. looks like an old one, with its faded green paint.

Weirdly, the one in my original post (reply #2785) was only installed about ten years ago, after the original 8-8-8 signal was replaced. The original used the two-arm type assembly (whatever the hell it's called). The current pole-mounted signal (seen in my photo) was only installed in 2013 or 2014.

[Ian]

One of the first FYA signals in District 6:

https://www.google.com/maps/@39.8873981,-75.4023402,3a,15y,288.15h,98.05t/data=!3m7!1e1!3m5!1sLVBFOAB_J8p78ngRvEXgSw!2e0!6s%2F%2Fgeo0.ggpht.com%2Fcbk%3Fpanoid%3DLVBFOAB_J8p78ngRvEXgSw%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D349.79083%26pitch%3D0%26thumbfov%3D100!7i16384!8i8192

This one happens to be two Econolite Buttonback 4-section signals.

There's a second intersection not too far away on US 1 with one facing each direction at the entrance to Thomas Chevrolet/Rocky Run YMCA that was installed within the last several months. It's too new to even be on street view.

[fwydriver405]

Apparently San Francisco is phasing out the "8-inch (200mm) traffic signal in a circle assembly" and installing new 12-inch (300mm) signals mounted on a pole-plumbizer mount. I wonder why...

There's a second intersection not too far away on US 1 with one facing each direction at the entrance to Thomas Chevrolet/Rocky Run YMCA that was installed within the last several months. It's too new to even be on street view.

Are the 8-inch (200mm) traffic signal on the sides meant for pedestrians, like what Connecticut does for ped signals at it's older installations?

[Ian]

There's a second intersection not too far away on US 1 with one facing each direction at the entrance to Thomas Chevrolet/Rocky Run YMCA that was installed within the last several months. It's too new to even be on street view.

Are the 8-inch (200mm) traffic signal on the sides meant for pedestrians, like what Connecticut does for ped signals at it's older installations?

You are correct. Connecticut is actually the only other state that I've seen this done consistently.

(also, hello fellow Black Bear!)

[jakeroot]

It's possible that older pole-plumbizer mounts have been replaced with the style in your photos. In fact the first one I ever noticed in Walnut Creek, Calif. in the mid-1990's had been replaced by 2010. Also the one in your first photo in Tacoma, Wa. looks like an old one, with its faded green paint.

Weirdly, the one in my original post (reply #2785) was only installed about ten years ago, after the original 8-8-8 signal was replaced. The original used the two-arm type assembly (whatever the hell it's called). The current pole-mounted signal (seen in my photo) was only installed in 2013 or 2014.

SignBridge:

Here's an example of what I find to be far more common. This is just up the street from my first image. It too was upgraded from 8-8-8 to 12-8-8 in 2013 or 2014, but used the same mounting mechanism as before (unlike my earlier image). I find this pole-mounting method to be far, far more common:

[SignBridge]

Right and that's definitely a better quality mounting. BTW, why does that city play around with 12-8-8 instead of just going with all 12-inch which is more common and better in my opinion.

[jakeroot]

Right and that's definitely a better quality mounting. BTW, why does that city play around with 12-8-8 instead of just going with all 12-inch which is more common and better in my opinion.

Their game-plan a few years ago was to replace almost all incandescent signals with LEDs, and upgrade all red indications to 12-inch (any that hadn't yet been replaced or installed new). I assume they would have replaced all indications with proper funding.

New signals use all 12-inch indications, with backplates and retroreflective borders. There was a period of time in the 2000s where backplates were installed without the retroreflective borders (this one dates to 2003). I believe the last 12-8-8 signal was installed in 2007, along S Hosmer St outside a new shopping center. Why exactly the new signal in 2003 got all 12-inch indications, yet the one in 2007 did not, I do not know nor understand. The city also no longer uses 4 or 5 section "yield on green" signals, opting for FYA signals now. This new practice replaces decades of "Tacoma Towers", which were basically just 5 section towers where two 12-inch arrows were tacked on to the bottom of the left-most signal. Newer 12-inch 5-section left turn signals used tower configurations, even when they weren't tacked on like before. Doghouses are very rare in Tacoma.

I don't know about the rest of the country, but 12-8-8 signals are very common in Pierce County, WA. I don't know why this is, but they are all over Tacoma and many surrounding municipalities. Pierce County made them the standard signal until around the early or mid 2000s, but have been upgrading them to all 12-inch indications over the last ten years. Tacoma has literally thousands of 8-inch displays. It would take a long time to replace them all. Recent initiatives to upgrade these signals have taken place, by replacing many protected-only left turn signals with FYAs, but this has been slow to happen because new computers are required to run them.

(I hope you were looking for a giant response! I've done a lot of research on Tacoma and it's very strange signal history.)

[mrsman]

Right and that's definitely a better quality mounting. BTW, why does that city play around with 12-8-8 instead of just going with all 12-inch which is more common and better in my opinion.

Their game-plan a few years ago was to replace almost all incandescent signals with LEDs, and upgrade all red indications to 12-inch (any that hadn't yet been replaced or installed new). I assume they would have replaced all indications with proper funding.

New signals use all 12-inch indications, with backplates and retroreflective borders. There was a period of time in the 2000s where backplates were installed without the retroreflective borders (this one dates to 2003). I believe the last 12-8-8 signal was installed in 2007, along S Hosmer St outside a new shopping center. Why exactly the new signal in 2003 got all 12-inch indications, yet the one in 2007 did not, I do not know nor understand. The city also no longer uses 4 or 5 section "yield on green" signals, opting for FYA signals now. This new practice replaces decades of "Tacoma Towers", which were basically just 5 section towers where two 12-inch arrows were tacked on to the bottom of the left-most signal. Newer 12-inch 5-section left turn signals used tower configurations, even when they weren't tacked on like before. Doghouses are very rare in Tacoma.

I don't know about the rest of the country, but 12-8-8 signals are very common in Pierce County, WA. I don't know why this is, but they are all over Tacoma and many surrounding municipalities. Pierce County made them the standard signal until around the early or mid 2000s, but have been upgrading them to all 12-inch indications over the last ten years. Tacoma has literally thousands of 8-inch displays. It would take a long time to replace them all. Recent initiatives to upgrade these signals have taken place, by replacing many protected-only left turn signals with FYAs, but this has been slow to happen because new computers are required to run them.

(I hope you were looking for a giant response! I've done a lot of research on Tacoma and it's very strange signal history.)

In my view, it makes sense for a city to prioritize replacing protected only lefts with FYAs because of the extra functionality that the new signal provides.  With a limited budget, I would certainly do that over changing 8-8-8 signals to 12-12-12.  And in many ways, converting 8-8-8 to 12-8-8 is a happy compromise.  It is a cheaper conversion.  It doesn't require changing the signal mounts in most cases.  And, it emphasizes the red.  Given the traffic calming trends in many places, it doesn't seem like DOTs want to convert signals to encourage people to drive faster, so no need to emphasize the green.

Of course, new signals are a different matter, as laws may require new installations of 12-12-12, but generally old signal hardware does not need to be converted under law unless there is a safety issue.

[jakeroot]

In my view, it makes sense for a city to prioritize replacing protected only lefts with FYAs because of the extra functionality that the new signal provides.  With a limited budget, I would certainly do that over changing 8-8-8 signals to 12-12-12.  And in many ways, converting 8-8-8 to 12-8-8 is a happy compromise.  It is a cheaper conversion.  It doesn't require changing the signal mounts in most cases.  And, it emphasizes the red.  Given the traffic calming trends in many places, it doesn't seem like DOTs want to convert signals to encourage people to drive faster, so no need to emphasize the green.

Of course, new signals are a different matter, as laws may require new installations of 12-12-12, but generally old signal hardware does not need to be converted under law unless there is a safety issue.

I can't help but think that the MUTCD still permits 8-inch signals because, at the distance from the stop line where it is permitted, it is sufficient. After all, lens sizes should be scaled appropriately for reach road. Low speed roads don't need huge signals, but freeways might benefit from signals even larger than 12 inches. Maybe.

Tacoma officials have told me, through school projects that I've been involved with, that they are not willing to widen any additional roads within city limits. To the extent necessary, they are focusing their efforts on improving intersection operations, and increasing multimodal connections through designating roads as primary routes for cycling, transit, freight, etc, or a combination of those. FYA signals have helped the city in this regard. Many of the FYAs that have been installed use leading pedestrian intervals, with automatic walk signals. The red arrow stays lit for about four seconds, before the FYA activates. The conversion of those 8-inch reds does meet the goal you mention. When you look at intersections like this one below, it seems to me that the 8-inch green signals are perfectly adequate for the low-speed environment (which describes most of Tacoma's roads):

[Amtrakprod]

Yellow signals? In California?
https://www.google.com/maps/@37.7030995,-122.4858098,3a,39.2y,334.05h,97.04t/data=!3m6!1e1!3m4!1s7R2T3iUgvaDP-fmGCg2UYw!2e0!7i16384!8i8192

[jakeroot]

Yellow signals? In California?
https://www.google.com/maps/@37.7030995,-122.4858098,3a,39.2y,334.05h,97.04t/data=!3m6!1e1!3m4!1s7R2T3iUgvaDP-fmGCg2UYw!2e0!7i16384!8i8192

That's definitely strange. Reminds me that I've not seen any yellow signals in Oregon either. Washington, on the other hand...

Fire station signals tend to be a little more unique than the average setup. I think they're one of the few situations where some municipalities call for red-colored signal housings. But California doesn't call for yellow signal housings in any particular situation that I've seen, so this is almost certainly a one-off setup. Well found.