Traffic light screwed up. Which sign/signal controls?

[1995hoo]

Background to question: See this Street View image of eastbound Constitution Avenue at 17th Street NW in Washington DC.

Notice the no-left-turn restriction from Constitution onto northbound 17th. It applies during the same hours as the one from southbound 17th onto eastbound Constitution (see the sign on the right side of the image). It's reinforced by a big light-up "No Left Turn" symbol (see the black box above the traffic light on the far left behind the burgundy Jeep).

This week, for whatever reason, the light is messed up during the evening rush hour such that the left-turn green arrow comes on even though the "No Left Turn" sign is lit; meanwhile, straight-ahead traffic still has a red light (so the result is nobody goes in any direction). What I'm wondering is, which sign/signal controls: If you're on Constitution and you wanted to go left there, can you go left because of the green arrow or must you instead obey the left-turn prohibition? Does the presence of the sign stating the no-left-turn hours make a difference in this equation (even though, quite frankly, the typeface is small enough that it's hard to read from across the intersection)–in other words, because there is a sign saying you can't go left between 4:00 and 6:30 Monday through Friday, does that mean the driver must obey that sign in preference to the green arrow that appears to authorize the turn?

My interest is primarily academic; I never turn left there even when it is allowed, and 99% of my trips through that intersection are en route to Verizon Center, which is well east of there, so there'd be no reason for me to use 17th Street. But when I saw the green arrow come on this past Tuesday afternoon en route to a game, and then again yesterday, I was first surprised (it's never done that before) and then intrigued by what might happen if tourist season rolls around, the light is still doing that, and a DC traffic cop decides to take advantage of tourists who follow the green arrow.

(I don't have a picture of the light cycle because the only camera I had with me was my iPhone camera and, since we were not the first car waiting on line at the red light, I would have had to zoom in too far for the image to be clear.)

[agentsteel53]

If you're on Constitution and you wanted to go left there, can you go left because of the green arrow or must you instead obey the left-turn prohibition?

I don't $ee any rea$on why any juri$diction could po$$ibly claim that the prohibition outweigh$ the green arrow.

[Duke87]

Well, given the details of the situation, it is perfectly safe to turn on the arrow so there is no practical reason not to do so.

But I'd be surprised if legally speaking the green arrow overrode two signs. Money is an obvious reason why, but it also makes sense from an engineering perspective to give prohibition precedence since then it's a safe failure. Better to have a situation where people are banned from doing something which is perfectly safe than to have a situation where people are permitted to do something which isn't.

Also worth pointing out that while you've observed the situation and know that oncoming traffic has a red there, a driver who isn't familiar with the situation couldn't be sure of that.

[Scott5114]

Can't say for sure legally, but I would be inclined to follow the most restrictive condition.

[roadman65]

The same may be said about certain intersections in NYC near the Queens- Midtown Tunnel.  You have traffic lights that are RED and have its green arrow going off at the same time.  The thing is,  there is no standard green as it is a one turn only situation where an arrow is used over the standard ball to show traffic the only way to go.  So it is like saying red and green at the same time.

My dad always said when I was driving as a young adult at the time I encountered it, to stop first.  Look! And then proceed when clear.  So I am assuming that this is the way New York allows a rare left turn on red.

Many states like Florida, allow in the law for left turns on red from one particular street to another if both are one way.  It cannot be made from a two way onto a one way or one way onto a two way!  Some states do not allow this type of turn at all, and then there is NYC with its unique default NTOR.

I am assuming my dad is correct on this matter, or was he guessing?  I always admired my dad and he is smart and he is well respected in his community with all looking up to him.  He usually is never wrong.

[kphoger]

How is no turn on red unique to New York?  Chicago has the same law.  I'm sure other large cities do as well, but haven't looked them up.

[NE2]

How is no turn on red unique to New York?  Chicago has the same law.

Nope. NYC is the only U.S. city that has a default no turn on red if no signs are posted.

[Duke87]

My dad always said when I was driving as a young adult at the time I encountered it, to stop first.  Look! And then proceed when clear.  So I am assuming that this is the way New York allows a rare left turn on red.

If you have a green arrow, it means there are no conflicting movements with greens, so you don't need to and shouldn't stop.

However, while it does also mean that the crosswalk you're turning into is in DON'T WALK phase, one cannot count on pedestrians to obey that and so some level of caution is necessary when in an area with pedestrian traffic as it would be for making any turn.


New York City has in recent years taken to using arrows for turns in areas with high pedestrian traffic even if there is no conflicting auto traffic to contend with. They let the pedestrians cross first and then give turning traffic the green. This is of course no guarantee that a car and a pedestrian won't find each other, but it reduces the risk.

[1995hoo]

How is no turn on red unique to New York?  Chicago has the same law.

Nope. NYC is the only U.S. city that has a default no turn on red if no signs are posted.

Yup. Only other place I know of in the USA and Canada that defaults to no turn on red is the Island of Montreal.

[Alps]

My dad always said when I was driving as a young adult at the time I encountered it, to stop first.  Look! And then proceed when clear. 

You would be run over in NYC. The only way to operate a motor vehicle is to move incessantly toward and through green and yellow lights, and only to stop on red. Notice no mention of pedestrians. That's intentional.

Re: the original question, if the sign says not to do it, don't do it. Signals can malfunction. (Static message) signs can not. They can be manufactured wrong, or become obsolete, but they cannot malfunction.

[roadman65]

My dad always said when I was driving as a young adult at the time I encountered it, to stop first.  Look! And then proceed when clear. 

You would be run over in NYC. The only way to operate a motor vehicle is to move incessantly toward and through green and yellow lights, and only to stop on red. Notice no mention of pedestrians. That's intentional.

Re: the original question, if the sign says not to do it, don't do it. Signals can malfunction. (Static message) signs can not. They can be manufactured wrong, or become obsolete, but they cannot malfunction.

Those light up signs that he was talking about in DC can.  He was not referring to a normal posted painted sign.

[Alps]

My dad always said when I was driving as a young adult at the time I encountered it, to stop first.  Look! And then proceed when clear. 

You would be run over in NYC. The only way to operate a motor vehicle is to move incessantly toward and through green and yellow lights, and only to stop on red. Notice no mention of pedestrians. That's intentional.

Re: the original question, if the sign says not to do it, don't do it. Signals can malfunction. (Static message) signs can not. They can be manufactured wrong, or become obsolete, but they cannot malfunction.

Those light up signs that he was talking about in DC can.  He was not referring to a normal posted painted sign.

True, but the "left turn hours" modifier to me is what would then govern.

[kphoger]

Sorry, I was thinking of U turns, not right on red.  I don't know why I got those two mixed up.

How is no turn on red unique to New York?  Chicago has the same law.

Nope. NYC is the only U.S. city that has a default no turn on red if no signs are posted.

[1995hoo]

My dad always said when I was driving as a young adult at the time I encountered it, to stop first.  Look! And then proceed when clear. 

You would be run over in NYC. The only way to operate a motor vehicle is to move incessantly toward and through green and yellow lights, and only to stop on red. Notice no mention of pedestrians. That's intentional.

Re: the original question, if the sign says not to do it, don't do it. Signals can malfunction. (Static message) signs can not. They can be manufactured wrong, or become obsolete, but they cannot malfunction.

Those light up signs that he was talking about in DC can.  He was not referring to a normal posted painted sign.

True, but the "left turn hours" modifier to me is what would then govern.

Yes, if you look at the Street View link in my original post, you'll see that intersection has both a metal sign with the no-left-turn symbol listing the hours, as well as a light-up sign up above the regular traffic light. In this case it's the green arrow signal that is–or was; I haven't driven that way since last Thursday–malfunctioning. We don't have another Caps game until February 28, so hopefully by then it will be fixed.

I think I'd probably come down to obeying the sign with the hours, but I also think that if someone not from the DC area saw the green arrow and turned anyway, it would be unreasonable for a cop to give a ticket (not that such things ever bother DC cops, of course).

What annoys me about the whole thing is that because the left-turn arrow comes on and nobody can go straight while it's on, we all wind up wasting our time sitting there waiting for this stupid light to change when nobody's turning.

[Duke87]

You would be run over in NYC. The only way to operate a motor vehicle is to move incessantly toward and through green and yellow lights, and only to stop on red. Notice no mention of pedestrians. That's intentional.

Why yield to pedestrians when you can just drive around them?

[agentsteel53]

in Europe, one occasionally sees traffic lights with STOP signs on them.  I never did quite figure out what to do at a green light.

[Ian]

in Europe, one occasionally sees traffic lights with STOP signs on them.  I never did quite figure out what to do at a green light.

That's odd. May be the STOP sign is there just in case the lights go out?

[agentsteel53]

That's odd. May be the STOP sign is there just in case the lights go out?

they were in Italy and south France, where traffic control devices are suggestions at best, so I just passed through green at low but nonzero speed, while keeping an eye out for anything that would need me to slam the brakes.