Multiple traffic signals on road

[formulanone]

Here's 5 for 1 left turn lane:
https://www.google.com/maps/@29.6175871,-82.3850285,3a,73.6y,318.69h,80.84t/data=!3m7!1e1!3m5!1sJPVdKe-fBfs8RkAIObKCDA!2e0!5s20110401T000000!7i13312!8i6656!6m1!1e1

They did move the right turn lane from that ramp with a stop sign to meet at the signal. Sadly, still no second left turn lane, it needed it back then (as seen in the picture), still needs it today, and they're building a Bass Pro Shops to the left now, but still no second left in sight. Anything beat 5 per lane?

Archer Road at I-75 gets extremely backed up for two reasons: University of Florida and/or Butler Plaza.

I'm guessing the fifth light is to aid eastbound right-turning traffic, so it knows when to yield to through traffic on FL 24.

[roadfro]

7 signal heads for two left turn lanes:
I-80 WB off ramp at Keystone Ave (exit 12). Reno, NV

This being a SPUI contributes somewhat to the high head count, but not entirely...
2 overhead on the bridge and 1 near-side post mount? Makes sense
2 overhead underneath the bridge? Good for the cars at the stop line.
2 way-far-side post mounts? Were they both really necessary...?

[tradephoric]

It just seems like the conventional suburban intersection isn't working anymore.  To increase capacity, turn lanes are added which increases the pedestrian crossing distance, which increases the required cycle length, which increases driver and pedestrian delays.   It's a vicious cycle.   

The way to fix it is to get pedestrian crossing distances under control.   Pick intersection designs where pedestrians only cross one direction of the street at a time (whatever design that may be).

[NE2]

It just seems like the conventional suburban intersection isn't working anymore.  To increase capacity, turn lanes are added which increases the pedestrian crossing distance, which increases the required cycle length, which increases driver and pedestrian delays.   It's a vicious cycle.   

The way to fix it is to get pedestrian crossing distances under control.   Pick intersection designs where pedestrians only cross one direction of the street at a time (whatever design that may be).

How does making peds wait for each direction decrease pedestrian delays?

[tradephoric]

If the cycle is too short, it'll just lead to major congestion. Gotta time it appropriately for the traffic out there.

If pedestrians are dictating how long the cycle length needs to run, then the pedestrian crossing is too long.  This is what you see when you drive around Florida.  Florida has massive intersections with long pedestrian crossing lengths.  To fit the peds, the signals run extremely long cycle lengths.  The longer the cycles, the longer the queue space needed and the harder it becomes to provide good signal progression along a corridor (there becomes a lot less flexibility when cycle lengths are too high).

So much improvement could be made to the standard suburban intersection design.  Florida is a good example on how NOT to design a suburban intersection.  Perhaps urban designs (such as one-way couplets) are more efficient than suburban intersections (that feature inefficient left-turns).  Urbanizing a suburban intersection isn't a bad thing. 

Ultimately, find a way to eliminate left-turn phases at suburban intersections and everyone would be better off.

[jakeroot]

Ultimately, find a way to eliminate left-turn phases at suburban intersections and everyone would be better off.

I've thought about removing left turn phases at single left turns. Eventually, traffic would get so bad that people would just give up.

[Brandon]

Ultimately, find a way to eliminate left-turn phases at suburban intersections and everyone would be better off.

I've thought about removing left turn phases at single left turns. Eventually, traffic would get so bad that people would just give up.

That doesn't work.  You'll have them blowing the red just to make the left turn.

[jakeroot]

Ultimately, find a way to eliminate left-turn phases at suburban intersections and everyone would be better off.

I've thought about removing left turn phases at single left turns. Eventually, traffic would get so bad that people would just give up.

That doesn't work.  You'll have them blowing the red just to make the left turn.

Disclaimer: I wasn't being completely serious. However, just get three or four people out in the intersection to wait. Guaranteed three or four left turns -- no left turn phase. Yes people will jump the red, but traffic will be so bad, the speeds will be safe.

[Jet380]

Five signals for a single lane at the interchange of National M1 and State Route 32 in Belmont, Queensland. There's a red light camera there so I guess you can't say you didn't see the red light! 


https://www.google.com.au/maps/place/Belmont+QLD+4153/@-27.5026767,153.1239439,3a,75y,99.83h,79.94t/data=!3m7!1e1!3m5!1skDjdD8W7JkyO0D_gbZdBOA!2e0!6s%2F%2Fgeo1.ggpht.com%2Fcbk%3Fpanoid%3DkDjdD8W7JkyO0D_gbZdBOA%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D299.08386%26pitch%3D0!7i13312!8i6656!4m2!3m1!1s0x6b915be60a5d3845:0x502a35af3de8030!6m1!1e1

[roadman65]

https://www.google.com/maps/@40.7414747,-74.3657327,3a,75y,35.35h,76.58t/data=!3m6!1e1!3m4!1sbzZfc3P4RG9x23R7gw4Zww!2e0!7i13312!8i6656

Three signal heads for a single turn lane.  Pan around to the right to see em all.  The right turn lane has three (two on the mast arm, and one side mounted at the stop bar) and only two left turn signal heads for two lanes devoted to turning left.
https://www.google.com/maps/@40.7416565,-74.365271,3a,75y,106.68h,96.65t/data=!3m6!1e1!3m4!1sosvFIAmxnje52UcewGcfsg!2e0!7i13312!8i6656

Whats wrong with this picture??

[Big John]

^^ There is also a near-side stop bar signal for the left turn, along with the median mast arm signal and the far-side post mounted signal.

[roadfro]

Here's a set right next to each other in Reno, NV that I've always been confused by:

Keystone Ave at California Ave
https://www.google.com/maps/@39.5161558,-119.8256675,3a,75y,163.8h,75.93t/data=!3m6!1e1!3m4!1sqY6BgWKRNrwHgAa7yxCiEQ!2e0!7i13312!8i6656!6m1!1e1
Keystone ends in a T intersection here. There are 3 signal heads for the right turn lane (a third is on the far side, somewhat hidden in bushes), only 1 for the left turn lane.

Booth St at California Ave
https://www.google.com/maps/@39.5154388,-119.8264639,3a,75y,180.15h,80.61t/data=!3m6!1e1!3m4!1sQhdtnoiS6jv6qRC1Z0q4hQ!2e0!7i13312!8i6656!6m1!1e1
Same situation: 3 right turn heads and 1 left turn head.


These are older signals that don't conform to current Nevada standards. But these still confuse me because the right turn has one extra signal head while the left turn has one less–even older signals in Nevada usually had a redundant signal head for a left turn lane, but these two intersections do not.

[PColumbus73]

At Keystone and California, the signal at the far back could be removed without an issue, since it was already obscured by the bushes

[roadfro]

Long term, City of Reno had plans to reconstruct these intersections as part of a greater project to rehab/replace the Keystone Ave bridge over the Trucker River. They were looking at several concepts for these and adjacent intersections that would mean reconstructing these signals.

[paulthemapguy]

Four?  Hahahahahahahaha!  That's not many.  I've seen six or seven at some intersections.

How about five for the through lane: https://goo.gl/maps/WhENUH6Cg8w

To be fair though, IDOT requires a minimum of three for the through movement and a minimum of two each for each turning movement.

You are right in my neck of the woods.  IDOT District 3 really goes ham with their signals. [kendall, grundy, lasalle, dekalb, and several other counties]

https://www.google.com/maps/@41.7032069,-88.3094446,3a,68.9y,27.26h,92.08t/data=!3m6!1e1!3m4!1sxM-xyhzEA--sn_RyuX1Y-A!2e0!7i13312!8i6656

This image is especially funny because the sixth signal head (on the right) doesn't even work.  Why bother to fix it when you have FIVE OTHER SIGNAL HEADS doing the job just fine?   

And here's an overkill signal in Kane County IL.  Five signal heads on one mast arm.  Plus 2 gives 7:
https://www.google.com/maps/@42.0852759,-88.3352641,3a,75y,356.56h,85.47t/data=!3m6!1e1!3m4!1svoEhS52xUTEsuuSDz8q0lA!2e0!7i13312!8i6656

[jakeroot]

Four?  Hahahahahahahaha!  That's not many.  I've seen six or seven at some intersections.

How about five for the through lane: https://goo.gl/maps/WhENUH6Cg8w

To be fair though, IDOT requires a minimum of three for the through movement and a minimum of two each for each turning movement.

https://www.google.com/maps/@41.7032069,-88.3094446,3a,68.9y,27.26h,92.08t/data=!3m6!1e1!3m4!1sxM-xyhzEA--sn_RyuX1Y-A!2e0!7i13312!8i6656

This image is especially funny because the sixth signal head (on the right) doesn't even work.  Why bother to fix it when you have FIVE OTHER SIGNAL HEADS doing the job just fine?   

In my opinion, mast-mounted signals should always supplement arm-mounted signals. If anything, the right-most arm-mounted signal could go. My thinking is that if you are behind a tall vehicle in the right-most lane, you may not be able to see the arm-mounted signals. In Washington State, mast-mounted signals are only used if the geometry of the intersection is slightly askew. Driving a small hatchback, I sometimes have issues seeing the signals (which are usually only on the overhead arm). IMO, California and Wisconsin do signals right: One near-side signal, at least two far-side, and always a combination of mast- and arm-mounted heads.

[Brandon]

Four?  Hahahahahahahaha!  That's not many.  I've seen six or seven at some intersections.

How about five for the through lane: https://goo.gl/maps/WhENUH6Cg8w

To be fair though, IDOT requires a minimum of three for the through movement and a minimum of two each for each turning movement.

https://www.google.com/maps/@41.7032069,-88.3094446,3a,68.9y,27.26h,92.08t/data=!3m6!1e1!3m4!1sxM-xyhzEA--sn_RyuX1Y-A!2e0!7i13312!8i6656

This image is especially funny because the sixth signal head (on the right) doesn't even work.  Why bother to fix it when you have FIVE OTHER SIGNAL HEADS doing the job just fine?   

In my opinion, mast-mounted signals should always supplement arm-mounted signals. If anything, the right-most arm-mounted signal could go.

However, as per IDOT policy, it cannot go.  One of the three-lamp signals could go, but not that tower.  IDOT requires a minimum of two signals per turning direction.

[jakeroot]

Four?  Hahahahahahahaha!  That's not many.  I've seen six or seven at some intersections.

How about five for the through lane: https://goo.gl/maps/WhENUH6Cg8w

To be fair though, IDOT requires a minimum of three for the through movement and a minimum of two each for each turning movement.

https://www.google.com/maps/@41.7032069,-88.3094446,3a,68.9y,27.26h,92.08t/data=!3m6!1e1!3m4!1sxM-xyhzEA--sn_RyuX1Y-A!2e0!7i13312!8i6656

This image is especially funny because the sixth signal head (on the right) doesn't even work.  Why bother to fix it when you have FIVE OTHER SIGNAL HEADS doing the job just fine?   

In my opinion, mast-mounted signals should always supplement arm-mounted signals. If anything, the right-most arm-mounted signal could go.

However, as per IDOT policy, it cannot go.  One of the three-lamp signals could go, but not that tower.  IDOT requires a minimum of two signals per turning direction.

And that's fine by me. I was simply stating that, in general, and particularly in this case, the arm-mounted signal should be the one to go, if one were to go (Paul was suggesting that the mast-mounted signal need not be fixed because of its redundancy, but in my opinion, the mast-mounted signal would be the better of the two to have functioning).

[paulthemapguy]

Four?  Hahahahahahahaha!  That's not many.  I've seen six or seven at some intersections.

How about five for the through lane: https://goo.gl/maps/WhENUH6Cg8w

To be fair though, IDOT requires a minimum of three for the through movement and a minimum of two each for each turning movement.

https://www.google.com/maps/@41.7032069,-88.3094446,3a,68.9y,27.26h,92.08t/data=!3m6!1e1!3m4!1sxM-xyhzEA--sn_RyuX1Y-A!2e0!7i13312!8i6656

This image is especially funny because the sixth signal head (on the right) doesn't even work.  Why bother to fix it when you have FIVE OTHER SIGNAL HEADS doing the job just fine?   

In my opinion, mast-mounted signals should always supplement arm-mounted signals. If anything, the right-most arm-mounted signal could go.

However, as per IDOT policy, it cannot go.  One of the three-lamp signals could go, but not that tower.  IDOT requires a minimum of two signals per turning direction.

And that's fine by me. I was simply stating that, in general, and particularly in this case, the arm-mounted signal should be the one to go, if one were to go (Paul was suggesting that the mast-mounted signal need not be fixed because of its redundancy, but in my opinion, the mast-mounted signal would be the better of the two to have functioning).

IDOT requires one signal per lane, and IDOT requires at least 2 signals per turning movement.
Here we have a left only, two through-lanes, and a right only.
As is common in the rest of the state, this could be accomplished by two 5-section heads with left arrows, and two 5-section heads with right arrows, a total of 4 (which works because 4 lanes).  Basically, take out the two 3-section heads and we're golden!  Like in this case just down the road to the west:

https://www.google.com/maps/@41.6721921,-88.3766748,3a,75y,255.58h,84.8t/data=!3m6!1e1!3m4!1sJYXguz95njLrkvK1BHtYkQ!2e0!7i3328!8i1664

[jakeroot]

While reading the British Columbia Signal Design Manual, I stumbled upon ~ 402.6.4, which covers where signals shall be placed. I found it rather interesting. While protected/permissive left turns need only two signal heads, protected-only left turns shall have at least three signal heads, if not more (dual turn lanes, for example). The signals shall be mounted as follows...

- One primary head shall be located in the far side raised median mounted at a height of 2.5m.
- One secondary head shall be located at the far left side of the intersection at a height of 2.5 m.
- One auxiliary head shall be located in the near side median mounted at a height of 1.25 m.
- If there is no raised median, then the primary head shall be mounted overhead on the signal pole arm. If there are no raised medians, the auxiliary head cannot be installed.

AFAICT, no overhead signals are required, lest the median is too narrow to accommodate a signal head.

https://goo.gl/a4pBEn (see page 82).

Here's an example of a protected left turn along the South Frasier Perimeter Road. This installation is roughly three to four years old (note that the left turn lane is to the left of the median).

[SignBridge]

I'll add my vote of approval to California's configuration and those states like Nevada and Illinois that are similar. A standard set-up of both overhead and post-mounted heads is the best combination, for good visibility under any and all traffic conditions. States that only follow the basic MUTCD standards have many installations that are barely adequate. And that includes my native New York.

[paulthemapguy]

I'll add my vote of approval to California's configuration and those states like Nevada and Illinois that are similar. A standard set-up of both overhead and post-mounted heads is the best combination, for good visibility under any and all traffic conditions. States that only follow the basic MUTCD standards have many installations that are barely adequate. And that includes my native New York.

Agreed.  With this approval, though, I'd also like to voice my dissent toward any regulations that are TOO specific.  That stuff from BC looks like it pigeon-holes things too much.  Not every intersection is a basic 4-way on flat terrain.  Laws and typical designs should be allowed room to shift, in order to adjust to the various sets of conditions you encounter.  That's what engineering is for!

[cl94]

I'll add my vote of approval to California's configuration and those states like Nevada and Illinois that are similar. A standard set-up of both overhead and post-mounted heads is the best combination, for good visibility under any and all traffic conditions. States that only follow the basic MUTCD standards have many installations that are barely adequate. And that includes my native New York.

Agreed.  With this approval, though, I'd also like to voice my dissent toward any regulations that are TOO specific.  That stuff from BC looks like it pigeon-holes things too much.  Not every intersection is a basic 4-way on flat terrain.  Laws and typical designs should be allowed room to shift, in order to adjust to the various sets of conditions you encounter.  That's what engineering is for!

There are many times when Illinois signals get quite excessive. A single-lane approach does not need 3 signals. 2 for 3-4 lanes isn't enough, but you don't need over 2 times as many signals as there are lanes.

[paulthemapguy]

There are many times when Illinois signals get quite excessive. A single-lane approach does not need 3 signals. 2 for 3-4 lanes isn't enough, but you don't need over 2 times as many signals as there are lanes.
[/quote]

Word.  When Illinois does go minimalist, this is what it looks like: 
https://goo.gl/maps/ihYjY2skout

If you want two signals for the left turn movement, and two signals for the straight movement, just put two 5-section heads up and you're done!  2 signals for 2 lanes, and 2 for each movement.  Done.  (You don't even need the 3-section head in the back, but IDOT puts those on all their cable-suspended signals anyway.  Even though they're usually useless.)

[signalman]

When Illinois does go minimalist, this is what it looks like: 
https://goo.gl/maps/ihYjY2skout

If you want two signals for the left turn movement, and two signals for the straight movement, just put two 5-section heads up and you're done!  2 signals for 2 lanes, and 2 for each movement.  Done.  (You don't even need the 3-section head in the back, but IDOT puts those on all their cable-suspended signals anyway.  Even though they're usually useless.)

I wouldn't say that the near-side signals are useless.  It helps motorists approaching the intersection see what color the signal is; especially if there's a large vehicle in the queue.  I'd agree that a 5 section tower would be overkill, but not a basic 3 section one.