California Traffic signals

[jeffandnicole]

There are places in CA where I'll still only see two green balls for three lanes of thru traffic.

Heh.  You wouldn't like driving in NJ then.  It wasn't unusual to find situations like this: One overhead signal beyond the stop line for FOUR lanes of traffic!  https://goo.gl/maps/n8gJJK4Bif92  (Well, the unusual thing would be finding a road with 4 lanes in one direction to begin with!  But a single overhead signal like shown above was quite common no matter how many lanes existed)

That is being phased out though.  The GSV linked above is from 2013.  The more recent ones show the traffic lights were upgraded to the standard one-per-lane.

[freebrickproductions]

There are places in CA where I'll still only see two green balls for three lanes of thru traffic.

Heh.  You wouldn't like driving in NJ then.  It wasn't unusual to find situations like this: One overhead signal beyond the stop line for FOUR lanes of traffic!  https://goo.gl/maps/n8gJJK4Bif92  (Well, the unusual thing would be finding a road with 4 lanes in one direction to begin with!  But a single overhead signal like shown above was quite common no matter how many lanes existed)

That is being phased out though.  The GSV linked above is from 2013.  The more recent ones show the traffic lights were upgraded to the standard one-per-lane.

Technically, there was two.

[SignBridge]

As jakeroot pointed out above, California uses their older configuration of a combination of post and overhead signal heads, not the current MUTCD recommendation of one overhead signal per lane.

We need to emphasize that is only a suggestion in the Manual. The actual standard still reads the same as it has for many years. Only one signal head is required in the driver's cone-of-vision; the second head is preferred in the cone, but not required. So California's configuration still meets Manual standards, and in my opinion is the better way to go. I've always thought that Calif's combination of post and overhead mounts gave the best visibility to all approaching traffic, especially when you're behind a large truck that blocks your view of the signals over the lanes. There is still a lot to be said for eye-level pole mounted heads.

[Revive 755]

Truthfully, backplates are really only necessary on overhead signals because that's where the sun is located.

Strongly disagree - a backplate can be a necessity on eastbound and westbound signals if there are no buildings or other permanent obstructions to the sun - deciduous trees don't count during the winter months.  Sunrise and sunset can be a problem for non-overhead mounted signal heads.  Backplates can also become necessary if the bracket mounted/post mounted heads are mounted high enough, mounted in front of a drop off, or mounted in front of a highly reflective building.

As jakeroot pointed out above, California uses their older configuration of a combination of post and overhead signal heads, not the current MUTCD recommendation of one overhead signal per lane.

We need to emphasize that is only a suggestion in the Manual. The actual standard still reads the same as it has for many years. Only one signal head is required in the driver's cone-of-vision; the second head is preferred in the cone, but not required. So California's configuration still meets Manual standards, and in my opinion is the better way to go. I've always thought that Calif's combination of post and overhead mounts gave the best visibility to all approaching traffic, especially when you're behind a large truck that blocks your view of the signals over the lanes. There is still a lot to be said for eye-level pole mounted heads.

I'm curious how that plays out in the courts in California.  Given how much some places try to obey all of the "should" statements in the MUTCD, I have to wonder if they lost in court for not following a "should" statement without adequate justification.

There are also Paragraphs 01 and 02 in 4D.12 to consider, from it which it may be possible to argue for better visibility than the minimum required by Figure 4D-4.

The primary consideration in signal face placement, aiming, and adjustment shall be to optimize the visibility of signal indications to approaching traffic.

Road users approaching a signalized intersection or other signalized area, such as a midblock crosswalk, shall be given a clear and unmistakable indication of their right-of-way assignment.

[jakeroot]

Not all drivers approaching an intersection have the same cone of vision. You can assume the front cars can see all signals, except near-side signals. Cars behind them, assuming they can't see over the front cars (quite common for me, driving a small hatchback), rely on near-side and corner signals to see. California, along with other states that I previously mentioned (AZ, NV, MN, WI, IL, CO, plus other states and several Canadian provinces) are the only places that really have the whole "cone of vision" thing down for more than just the drivers up front. Too many states place signals just overhead. Which is fine, if you're in the front. But it's no good for everyone else, especially if the car up front is tall.

Truthfully, backplates are really only necessary on overhead signals because that's where the sun is located.

Strongly disagree - a backplate can be a necessity on eastbound and westbound signals if there are no buildings or other permanent obstructions to the sun - deciduous trees don't count during the winter months.  Sunrise and sunset can be a problem for non-overhead mounted signal heads.  Backplates can also become necessary if the bracket mounted/post mounted heads are mounted high enough, mounted in front of a drop off, or mounted in front of a highly reflective building.

Fair points. From my experience driving in BC (where, for the most part, secondary signals do not have backplates), I've never struggled to see post-mounted signals. When the sun was an issue, I generally just looked at the signal that was easier to see (sun near horizon?...overhead; sun overhead?...post-mounted). If only one type of signal was provided, certainly backplates would be necessary, because there would be times where none of the signals would be visible, for various reasons. But when both overhead and side/post mounted signals are provided, I'm generally fine with only using backplates overhead, because during most of the day (assuming the sun is out), they are the harder of the signals to see. There's also a crowding issue, where closely spaced post-mounted signals sometimes can't have backplates because they are placed too close together.

[SignBridge]

Jakeroot, many of your points are well taken. But the "cone-of-vision" that we speak about in the Manual is very specific. If you look at the MUTCD on the FHWA website, there is a detailed diagram in Sec. 4D-13, Fig. 4D-4, that shows all the distances, angles, etc.

[jakeroot]

Jakeroot, many of your points are well taken. But the "cone-of-vision" that we speak about in the Manual is very specific. If you look at the MUTCD on the FHWA website, there is a detailed diagram in Sec. 4D-13, Fig. 4D-4, that shows all the distances, angles, etc.

I see. Judging by the diagram, a mast-mounted through signal, in addition to one overhead signal, should satisfy the requirements, assuming the road isn't too wide...

[mrsman]

My only gripe about California's signals is that their signal heads aren't as abundant as they could be at some intersections.  I know the MUTCD specifies that there should always be at least two green balls for thru traffic, and I'm not aware of anything specifically requesting multiple signal heads for turning traffic.  But it still bothers me when I only see one signal head with left arrows, even if there's only one left turn lane.  Same goes for right arrows.  There should be a backup signal head for all movements in case one dies out, in my opinion.  I also think there should be one signal head for each thru lane...There are places in CA where I'll still only see two green balls for three lanes of thru traffic.

I need some clarification here. California, evidently, requires a pole-mounted signal head for each movement, and a minimum of two signals per movement. A typical setup, assuming three through lanes, two left turn lanes (no u-turn permitted), and one right turn lane, would be to have one left turn signal overhead, one left turn signal mast/pole mounted on the far left, one or two through signals mounted overhead, and two 5-section towers mounted on the far-right and near-right side of the intersection (the near-side being pole mounted and the far side being attached to the mast usually). California does not prescribe to the signal-per-lane philosophy, instead opting for signals in other areas, such as in corners, and attached to poles or masts. It's not unusual to see one overhead signal (left or straight movement) for three lanes, with additional supplementary signals in the corners of the intersection.

Maybe you can provide an example.  As jakeroot mentioned: Every traffic signal with left turn arrows that I've come across in CA has the arrows facing traffic in at least two places.  Left turn signals are generally found on the mast arm, the far left corner on a pole, the far median, or the near-side median.  Every left turn that I can think of has the left signal on two of these places.  Right turn signals, which are a great help to keep traffic moving while the complementary left (u-turn prohibited) is in a protected phase, are almost always both on the near-side right corner and the far-side right corner.  I am struggling to think of any situation where a turning arrow is only shown once.

[calsignalfan85]

I do think it's strange that so many of their left turn signals are hung from the top, whereas the rest of the signals are mast-arm mounted somewhere between the top-middle and/or middle.

From what I saw when I was out there last summer, I think California is moving away from hanging their outermost signal heads from the top. All of the new overheads I saw now have the plumbizer mounted between the amber and red sections. Here's a newer example in Dana Point...

Protected Left turn signals have been mounted between the red and amber lights for decades, I mean from the 70s to present. They are mounted how ever the installer feels. I've seen them mounted from the top on one block and on the next block they are mounted between the red and amber. It can vary.

[jakeroot]

I do think it's strange that so many of their left turn signals are hung from the top, whereas the rest of the signals are mast-arm mounted somewhere between the top-middle and/or middle.

From what I saw when I was out there last summer, I think California is moving away from hanging their outermost signal heads from the top. All of the new overheads I saw now have the plumbizer mounted between the amber and red sections. Here's a newer example in Dana Point...

https://c1.staticflickr.com/3/2948/32805053304_3ee7d9e075_z.jpg

Protected Left turn signals have been mounted between the red and amber lights for decades, I mean from the 70s to present. They are mounted how ever the installer feels. I've seen them mounted from the top on one block and on the next block they are mounted between the red and amber. It can vary.

But, specifically, why is it that the left turn signal is/can be hung from the top, but never the through signal? I can't recall ever seeing a through signal hung from the top, except for visibility (see here). If the installer chose to hang the left turn signal, why did he mount the through signal with the "plumbizer" attached between the red and amber orbs (as is standard practice for most signal heads, except when those secondary half-inch-wide poles are attached in between the signal and the mast arm)?

[roadfro]

I do think it's strange that so many of their left turn signals are hung from the top, whereas the rest of the signals are mast-arm mounted somewhere between the top-middle and/or middle.

From what I saw when I was out there last summer, I think California is moving away from hanging their outermost signal heads from the top. All of the new overheads I saw now have the plumbizer mounted between the amber and red sections. Here's a newer example in Dana Point...

https://c1.staticflickr.com/3/2948/32805053304_3ee7d9e075_z.jpg

Protected Left turn signals have been mounted between the red and amber lights for decades, I mean from the 70s to present. They are mounted how ever the installer feels. I've seen them mounted from the top on one block and on the next block they are mounted between the red and amber. It can vary.

But, specifically, why is it that the left turn signal is/can be hung from the top, but never the through signal? I can't recall ever seeing a through signal hung from the top, except for visibility (see here). If the installer chose to hang the left turn signal, why did he mount the through signal with the "plumbizer" attached between the red and amber orbs (as is standard practice for most signal heads, except when those secondary half-inch-wide poles are attached in between the signal and the mast arm)?

Ultimately, I think it probably has just come down to agency preference or parts available.

One scenario I can think of is that perhaps a protected left turn was installed where originally there was a permitted left using a standard 3-section circular display. In this instance, maybe the agency installed the left turn signal hanging from the top to provide a visual distinction that the traffic control had changed. Just a theory, but plausible. Another theory could be that the agency got a big supply of left turn signal heads from a manufacturer that already had plumbizers attached to the top, and it wasn't worth the time and expense to deal with the supplier to get a new shipment with plumbizers between red and yellow.



Some Nevada examples of where signal heads are mounted differently than normal for no apparent reason:

Here's an older signal installation in Sparks, NV (McCarran Blvd & Victorian Ave/I-80 EB off ramp), which mimics the more traditional California setups with curved mast arms:
McCarran Blvd NB - Interestingly, this also uses the "left turn signal mounted from the top" approach. That installation style is not common around here.
McCarran Blvd SB - The right thru signal is actually mounted with plumbizer between yellow and green, which seems like an effort to equalize height between the three thru signals until you realize this *wasn't* done for the opposite direction (as seen in the other link). But this is something I've seen this done a couple times in California as well.

Another older installation in Sparks, NV (Sparks Blvd & Prater Way). This install uses straight mast arms.
Prater Way EB - left turn signal mounted with plumbizer between yellow and green sections, despite no obvious reason to do so and all other overhead signals at this intersection mounted normally.

[Amtrakprod]

California  Traffic signal  are most interest In the USA.

LGMS210

I love California traffic signals, but they have a severe lack of Permissive Left Turns, FYAs are coming to Cali but slowly


iPhone

[capt.ron]

Anaheim area has a few straight mast arms. They are becoming more rare these days, but in the 90s there were a bunch of installations that utilized straight mast arms in Anaheim around the Knott's Berry Farm area.

8500 S Knott Ave at Crescent.

https://goo.gl/maps/jZMTKVwM5A62

The old traffic signal at La Palma & Gilbert was a straight mast arm with one traffic light head. It has been replaced with a longer curved mast arm. I think there may be a few straight mast arms around LAX as well

[jakeroot]

Anaheim area has a few straight mast arms. They are becoming more rare these days, but in the 90s there were a bunch of installations that utilized straight mast arms in Anaheim around the Knott's Berry Farm area.

8500 S Knott Ave at Crescent.

https://goo.gl/maps/jZMTKVwM5A62

The old traffic signal at La Palma & Gilbert was a straight mast arm with one traffic light head. It has been replaced with a longer curved mast arm. I think there may be a few straight mast arms around LAX as well

Could you be more specific as to which "La Palma & Gilbert" you are referring to? The one in Anaheim has four mast arms that are clearly quite old, and all are curved. The signals themselves are quite worn. I don't get the impression these were the replacements for anything, anytime within the last 20 years at least.

edit: geography.

[FreewayDan]

Anaheim area has a few straight mast arms. They are becoming more rare these days, but in the 90s there were a bunch of installations that utilized straight mast arms in Anaheim around the Knott's Berry Farm area.

8500 S Knott Ave at Crescent.

https://goo.gl/maps/jZMTKVwM5A62

The old traffic signal at La Palma & Gilbert was a straight mast arm with one traffic light head. It has been replaced with a longer curved mast arm. I think there may be a few straight mast arms around LAX as well

Could you be more specific as to which "La Palma & Gilbert" you are referring to? The one in Buena Park has four mast arms that are clearly quite old, and all are curved. The signals themselves are quite worn. I don't get the impression these were the replacements for anything, anytime within the last 20 years at least.

The old traffic signal at La Palma Avenue & Gilbert Street in Anaheim had resembled this signal on northbound Euclid Street at Glenoaks Avenue: https://goo.gl/maps/CSsPuJzqFbBTkqW99

Buena Park has the majority of the straight mast arm traffic signals left in Orange County.  Other areas of Orange County where straight mast signals are (or were) utilized include:

• La Veta Avenue (east and westbound) at Main Street in Orange
  (no longer exists)
• Westbound Katella Avenue at Lexington Drive in Los Alamitos
  (no longer exists)
• Barranca Pkwy at Armstrong Avenue in Irvine
  https://goo.gl/maps/HcVyTDa38ubpEHyH7
• Orangethrope Avenue at Walker Street in La Palma
  https://goo.gl/maps/9y8Q48asMPi2MHB9A
• Eastbound Chapman Avenue at Victoria Drive in Fullerton
  https://goo.gl/maps/7sTNVqR4gTkJ4W7f9
• Newport Center Drive at Santa Rosa Drive in Newport Beach
  https://goo.gl/maps/1g3eZKTiitcT9ffr6

Brookhust Street in Anaheim at La Palma Avenue and Ball Road used to have straight mast arm traffic signals until around 20 years ago.

[SignBridge]

The last time I visited Los Angeles, back in 1997, there were straight mast arms in the downtown Glendale business district as I recall.

[jakeroot]

There are also some in Beverly Hills, although they are attached using guy wires as well.

Anaheim area has a few straight mast arms. They are becoming more rare these days, but in the 90s there were a bunch of installations that utilized straight mast arms in Anaheim around the Knott's Berry Farm area.

8500 S Knott Ave at Crescent.

https://goo.gl/maps/jZMTKVwM5A62

The old traffic signal at La Palma & Gilbert was a straight mast arm with one traffic light head. It has been replaced with a longer curved mast arm. I think there may be a few straight mast arms around LAX as well

Could you be more specific as to which "La Palma & Gilbert" you are referring to? The one in Buena Park has four mast arms that are clearly quite old, and all are curved. The signals themselves are quite worn. I don't get the impression these were the replacements for anything, anytime within the last 20 years at least.

The old traffic signal at La Palma Avenue & Gilbert Street in Anaheim had resembled this signal on northbound Euclid Street at Glenoaks Avenue: https://goo.gl/maps/CSsPuJzqFbBTkqW99
...
Brookhust Street in Anaheim at La Palma Avenue and Ball Road used to have straight mast arm traffic signals until around 20 years ago.

I gotcha. What you consider "old" is "very old" to me, since the current signal (20+ years old) already seem pretty old to me. I certainly wouldn't qualify it as "new" when you consider the current state of the intersection anyhow, with the faded and chipped paint, and the old signals with the raised dot in the middle (a brand that I know has been out of production for a while).

[capt.ron]

Anaheim area has a few straight mast arms. They are becoming more rare these days, but in the 90s there were a bunch of installations that utilized straight mast arms in Anaheim around the Knott's Berry Farm area.

8500 S Knott Ave at Crescent.

https://goo.gl/maps/jZMTKVwM5A62

The old traffic signal at La Palma & Gilbert was a straight mast arm with one traffic light head. It has been replaced with a longer curved mast arm. I think there may be a few straight mast arms around LAX as well

Could you be more specific as to which "La Palma & Gilbert" you are referring to? The one in Buena Park has four mast arms that are clearly quite old, and all are curved. The signals themselves are quite worn. I don't get the impression these were the replacements for anything, anytime within the last 20 years at least.

The old traffic signal at La Palma Avenue & Gilbert Street in Anaheim had resembled this signal on northbound Euclid Street at Glenoaks Avenue: https://goo.gl/maps/CSsPuJzqFbBTkqW99

Buena Park has the majority of the straight mast arm traffic signals left in Orange County.  Other areas of Orange County where straight mast signals are utilized include:

• La Veta Avenue (east and westbound) at Main Street in Orange
  (no longer exists)
• Westbound Katella Avenue at Lexington Drive in Los Alamitos
  (no longer exists)
• Barranca Pkwy at Armstrong Avenue in Irvine
  https://goo.gl/maps/HcVyTDa38ubpEHyH7
• Orangethrope Avenue at Walker Street in La Palma
  https://goo.gl/maps/9y8Q48asMPi2MHB9A
• Eastbound Chapman Avenue at Victoria Drive in Fullerton
  https://goo.gl/maps/7sTNVqR4gTkJ4W7f9
• Newport Center Drive at Santa Rosa Drive in Newport Beach
  https://goo.gl/maps/1g3eZKTiitcT9ffr6

Brookhurst Street in Anaheim at La Palma Avenue and Ball Road used to have straight mast arm traffic signals until around 20 years ago.

Yep. I'm guessing when they widened the La Palma bridge over I-5 in the late 1990's / early 2000's, the traffic signals at La Palma & Gilbert also got upgraded. Back when I was young, the old La Palma overpass (over I-5 and the RR) was 2 lane and curved. I remember it being the straight mast arm(s) in 1992 when I visited SoCal.

[CalMark123]

As someone who does not work in traffic engineering, I loved reading this discussion!  I never knew that anyone else paid such close attention to the design and engineering of traffic signals.   

I've lived in California for over 20 years and I still feel grateful that so much thought and considerations goes into the way the traffic signals are set up in this state.  The angled masts are the best, in my opinion!  Drivers should see an arc of lights as they approach a signaled intersection.  For the most part, California does this perfectly.  I also love that the signals are often set up with varying distances from the driver's perspective so that depth perception issues are covered as well.

I grew up in Florida and return to visit occasionally.  The old signals hanging from wires strung across the intersections are still common there.  They're so ugly, and so much less visually effective.  Seeing them in person always makes me appreciate California even more.

[SignBridge]

CalMark123, I agree with you about Calif. signal configuration.

And you're not the only one. I lived most of my life never knowing that so many other people were interested in this stuff the same as I've been since I was a kid. Thanks to the internet and forums like this it's been a real awakening!

[CalMark123]

CalMark123, I agree with you about Calif. signal configuration.

And you're not the only one. I lived most of my life never knowing that so many other people were interested in this stuff the same as I've been since I was a kid. Thanks to the internet and forums like this it's been a real awakening!

Agreed!     At least it's been a source of amusement for me from time to time.  I remember telling a friend years ago about all of the things I didn't like about Florida.  I finished my rant of complaints with, "And I don't even like the way they hang the traffic signals!"   I'm sure he thought I was a little unhinged.   

[UCFKnights]

CalMark123, I agree with you about Calif. signal configuration.

And you're not the only one. I lived most of my life never knowing that so many other people were interested in this stuff the same as I've been since I was a kid. Thanks to the internet and forums like this it's been a real awakening!

Agreed!     At least it's been a source of amusement for me from time to time.  I remember telling a friend years ago about all of the things I didn't like about Florida.  I finished my rant of complaints with, "And I don't even like the way they hang the traffic signals!"   I'm sure he thought I was a little unhinged. 

When I lived in South Florida, most of it was pretty good on the span wires about putting at least one signal per lane, plus an additional near signal centered on the road. If there were 2 left turn lanes, that would also almost always get a near signal as well. After the hurricanes, I was a little disappointed about the switch from hanging from wires to mast arms for most new installations, as we lost the near signal in the process most of the time.  When I moved to Orlando, I couldn't believe how awful they were at installing span wires. Then again, I also couldn't believe how awful they were at installing and maintaining mast arms as well

[SignBridge]

Don't many parts of Florida use mast-arms with horizontal signals similar to Texas practice?

[CalMark123]

Don't many parts of Florida use mast-arms with horizontal signals similar to Texas practice?

My recollection is that the downtowns of Florida's larger cities use mast-arms with horizontal signals, but I don't see much consistency in other areas.

Just as an example, here's an image from one of the busiest intersections in Hillsborough County (Tampa area):

https://goo.gl/maps/QBA6KdjAcGo6KFmt6

[SignBridge]

Wow, that may be the longest diagonal span-wire with the most signals heads I've ever seen.