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I have been travelling in California recently, and in a sorta-rural area I came across a confusing left-turn lane traffic light setup.

It seems there is no left-turn light on the overhead pole directly in front of the driver in the left turn lane, but instead on a separate pole on the left corner of the road, to the left of oncoming traffic.

That is bad enough, if you don't notice that separate pole you will think the intersection is unprotected. What's more confusing, though, is that there are two circular traffic lights on the overhead pole directly in front of the driver that can have two different colors. What is this setup, what should I do?

Here are two pictures of the intersection I encountered. The lights were like this down the entire road. Here is the Google Street View.

Confusing left turn signal:

Left turn traffic light on separate pole on the left corner of the road

Overhead lights:

Two circular traffic lights on the pole directly in front of the driver, two different colors

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    I guess i dont see why there is any confusion. I dont live in California Im in michigan and to me I dont find this confusing at all. Youre sitting on the lane to turn left why wouldnt you think the light right above your lane is for turning left?
    – JonH
    Jan 3 at 16:43
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    This light layout can exist because the lights on the corner predate the overhead lights, somewhat common in older areas where the overhead lights are significantly more expensive to deploy; left behind because the existing populace expects it at this location. Older intersection are often smaller and this places signals high above the view of the driver, where the drive might have to lean forward to view the signal, the lower signal is easier to view. The red arrow makes it explicit that it is commanding left-turning traffic.
    – RomaH
    Jan 3 at 16:50
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    Not completely "common", but by no means is this weird. Also, it doesn't matter which one you actually look at, the two left-turn signals will be wired together and they'll always stay in sync.
    – FreeMan
    Jan 3 at 17:28
  • @RomaH thanks, interesting! Any idea why they use a circular red light on the overhead light instead of a red arrow? Jan 3 at 19:56
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    @FranckDernoncourt Not certain, if I had to guess mostly cost. Red arrow in the US states I have been usually have a more 'strict' interpretation. In some states your can make a right on red at an intersection, but only if it does not have red arrow; you can make a right on a full lens red if state law permits. I have seen red arrows pointing ahead/straight but not often. I work with a City's road department but not in it, so much is just gleaned from working alongside and as a US driver.
    – RomaH
    Jan 3 at 20:13

3 Answers 3

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Use the light that corresponds to your left turning lane based on the sign beside the light:

red left turn signal on Desert Knoll intersection

Or, to answer the question more precisely, you can use either light - they indicate the same cycle. The shorter one could be there for a number of reasons (tall vehicles, the lovely California sunshine in your face, legal requirements) and I agree that having both can be confusing if you're not used to it.

The overhead red light in this situation is also commonly a red arrow rather than a red circle, as mentioned in the discussion on Franck's answer.

Even if the red light is a circle, the green light will normally be an arrow, to indicate that the left turn is protected from oncoming traffic. If it's still a green circle, I would treat this as a regular unprotected left turn!

Here's another example, from the next intersection north on Seventh & Victor Street:

red light circle on Victor St street view Left turn lane light, red circle

green light arrow on Victor St street view Left turn lane light, green arrow

Update: Funnily enough, your street view link also shows that there's a green arrow instead of a dot on that very light, though it's hard to see from the side street's angle:

enter image description here

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  • My local driver's ed place said whaddup. Jan 4 at 7:04
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Follow the light with the arrow if you're turning left (i.e., the light on the separate pole on the right corner of the road, on the oncoming traffic's right).

enter image description here

In California:

A driver facing a steady red arrow signal shall not enter the intersection to make the movement indicated by the arrow.

It should have the same color as light 1 below (notice the black-and-white arrow sign next to it):

enter image description here

Lights 2 and 3 are for going straight. What a mess ✞

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    @Coffee'dUpHacker Yes, supposed to be an arrow but sometimes in the US they use a circle. No idea why. Jan 3 at 6:13
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    The circular red light has the arrow posted NEXT to it indicating it is for cars that are turning. I am more surprised that there seem to be two lanes going straight ahead and yet light 3 is on the side rather than on the gantry next to light 2
    – Dragonel
    Jan 3 at 13:54
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    @FranckDernoncourt A green arrow and a green circle do not mean the same thing. In Canada (BC at least), they also have flashing green arrows Jan 3 at 15:37
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    @Coffee'dUpHacker red arrows have a complicated history in the US. They didn't exist prior to the 1980s, then they were added, then proposed for removal, then made optional, then made mandatory (that last in 2009), but existing signals are grandfathered as long as they last. Plus I suspect many states are tired of the whole thing and willing to just ignore it.
    – hobbs
    Jan 3 at 21:29
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    @user3067860 it was for left, but you've brought up another thing that's been through changes. Some states allow right turns on a red arrow after stopping unless there is a NO TURN ON RED sign. Others don't. Which is why there is now a RIGHT ON RED ARROW AFTER STOP sign in MUTCD.
    – hobbs
    Jan 3 at 22:06
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They are the same. Obey the non-broken one.

The bulbs are hard-wired in parallel and are driven off the same controller ports. The controller doesn't even know there are 2 signal heads. (Maybe).

As implied, they are there to provide redundancy both for bulb failure and sight lines (truck blocking view of forward one).

If there's only one signal and it fails, it requires an immediate response from maintenance, or traffic will be snarled. Two heads mean "fix it in a day or two". That's the real reason forward has 2 heads.

Those are the best two places to put two left-turn heads.


I say "maybe" because newer controllers can sense current draw changes, and will "phone home" to report a bulb out. Depending on design it may need 1 bulb per port. (This is also a hindrance in LED adoption, ask anyone who tried LED turn signals and had their blinker go crazy or the console report bulbs out).

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