Combining Traffic Arrows

[Zmapper]

I was mapping out a fictional redesign of 42nd and 8th ave in New York when I realized something; I need combined traffic arrows! So to replace the 4 head signal in use today I created a 3 head one.



Any opinions or comments?

[6a]

I saw one around here that uses a single head for the yellow and green arrows.  I actually went back and stared at it to make sure I wasn't seeing things, haha.  I think a red arrow is a no-no in the MUTCD (but don't tell North Carolina.)

[Alps]

I've seen multi-arrow lenses like that on old signals (such as one in Bergen County), where because they were incandescent you couldn't have this possibility.  My concern is that for older drivers or drivers with poorer vision (still within legal limits), they will see two lights and may not be able to tell which arrow is which.  The idea behind separate lenses is to try to distinguish them - note that the MUTCD does not allow straight arrows anymore, presumably so that you can tell (based on placement) whether something is a left or right arrow, and then the big shiny ball becomes the overall or straight signal.

[Zmapper]

To clarify what I was saying, I do not mean for the lights to come on at separate times. I mean for them to replace the 4 head signal commonly in use today. So all of the green would light up at once, all of the yellow would light up at once, and all of the red would light up at once.

[Alps]

In that case, as I said, it was done years ago, and probably abandoned due to the difficulty of seeing the arrows - but LED technology may help now.  I understand that unlike a green ball, this signifies left turns are protected - but here's where I say "use the flashing green from Canada."

[froggie]

IMO, the 4-lens signal with the green arrow still fits the bill.  The dual arrows on this idea would to me be difficult to see, even with LED lenses.

[blue lightning]

There's an intersection near Strongsville that has a setup where the left two lights are 3 light stacks, but the yellow and green light also have yellow and green arrow, so in some phases you have a red ball with a green arrow, which then turns to red ball yellow arrow, then red ball only. During a full forward its just a green ball.

EDIT: Something like this (not sure if the 2nd right lane is a both thru and right, it might be just a right only)

[froggie]

All of which is very wrong.  Though Ohio may be blazing their own trail here, the Federal MUTCD explicitly prohibits having both a circular red and a green arrow lit on the same signal at the same time.

Looking at your graphic, the only signal that is even remotely allowable given the lane configuration is the one in the far right lane.  Though if the second lane is a right-turn only, then that signal would also be allowable.  The two on the left should be swapped, with the far left lane having a green arrow instead of a circular green....assuming that left turns are protected here and coincide with the through (straight ahead) green phase.

[agentsteel53]

the Federal MUTCD explicitly prohibits having both a circular red and a green arrow lit on the same signal at the same time.

I see this all the time in California.  What is the correct way to allow a right turn given that there is left-turning traffic in the exactly opposite arc?  (Traffic from the right has the green left arrow and is turning left.)

[iwishiwascanadian]

I don't know if this is pertinent to the thread, but couldn't it possible to put two lights together like what they do in the Washington, DC or Australia?  I could be totally wrong though so...

[TheStranger]

the Federal MUTCD explicitly prohibits having both a circular red and a green arrow lit on the same signal at the same time.

I see this all the time in California.  What is the correct way to allow a right turn given that there is left-turning traffic in the exactly opposite arc?  (Traffic from the right has the green left arrow and is turning left.)

My guess - and I think this is how I've usually seen it - is that the mainline straight lanes get the red circular lights, while only the rightmost lane has the right green arrow in its own signal assembly.

[froggie]

I see this all the time in California.  What is the correct way to allow a right turn given that there is left-turning traffic in the exactly opposite arc?  (Traffic from the right has the green left arrow and is turning left.)

There are two ways to do it.  One is as Chris mentions.  The other (which coincidentally I see every day on my commute) is to have the rightmost signal be a 5-lens signal...whether it be a doghouse, horizontal, or vertical...where the right green arrow coincides with the "opposite arc" movement, but the circular red remains lit (*see below*).

* I should clarify my previous statement.  Having a circular red and a green arrow at the same time is prohibited only if it's a 3-lens signal.  A 5-lens signal with both lights on is allowed.

[Scott5114]

I see this all the time in California.  What is the correct way to allow a right turn given that there is left-turning traffic in the exactly opposite arc?  (Traffic from the right has the green left arrow and is turning left.)

I would be inclined to say don't signal it at all, allow people to synthesize "right turn on red + no traffic coming this way = I can turn right".

[mightyace]

^^^

There is a simple reason to signal a right turn with a green arrow.

If I have a red light and no right turn arrow, by law, I'm supposed to stop before continuing.  If there is a green arrow, I do not have to stop.

[Scott5114]

But one must weigh the cost of the extra wiring/programming and such against the time savings of not having to stop. Since you're only going to be stopped briefly, is it really worth it?

[froggie]

Depends on three things:

- Traffic levels....if there is a large amount of right-turning traffic, it makes sense.  My commute route has four such examples.

- Whether the signal has a circular red or a red arrow.  This is important because there are 9 states (plus DC and PR) that prohibit a right turn on a red arrow.

- Some municipalities...notably New York City and Montreal...expressly prohibit "No Turn On Red" period, unless signed/signaled otherwise.

[realjd]

You'll occasionally see a combined arrow like that in Mexico:

http://maps.google.com/?ie=UTF8&ll=20.478276,-86.972955&spn=0.003739,0.006866&t=h&z=18&layer=c&cbll=20.478177,-86.972981&panoid=HDaBwhrTixGre8Cr_0OAFw&cbp=12,201.59,,0,1.48

[agentsteel53]

But one must weigh the cost of the extra wiring/programming and such against the time savings of not having to stop. Since you're only going to be stopped briefly, is it really worth it?

the wiring is minimal.  The state of the intersection already exists (green left arrow), it's just a matter of activating one more signal (corresponding green right arrow). 

really, anything that prevents a stop-and-go is a win in my book. 

[codyg1985]

Some traffic signals in Madison County, AL and in Huntsville, AL have two three-lens signal heads that allow for left turns and straight movements at the same time. The left signal head has a green arrow while the right one has a green ball.

This configuration is used a lot at intersections of a smaller road or shopping center and an arterial. It allows for each approach of the smaller road to go one at a time.

[countysigns]

There's an intersection near Strongsville that has a setup where the left two lights are 3 light stacks, but the yellow and green light also have yellow and green arrow, so in some phases you have a red ball with a green arrow, which then turns to red ball yellow arrow, then red ball only. During a full forward its just a green ball.

EDIT: Something like this (not sure if the 2nd right lane is a both thru and right, it might be just a right only)

Downtown Toledo used to be full of red light and green arrow signals.  In the link I've posted, the 1970  "traffic safety law" is noted that ends this type of setup.

http://news.google.com/newspapers?id=VXEUAAAAIBAJ&sjid=_gEEAAAAIBAJ&dq=traffic%20signals&pg=6671%2C1457191

[mightyace]

But one must weigh the cost of the extra wiring/programming and such against the time savings of not having to stop. Since you're only going to be stopped briefly, is it really worth it?

the wiring is minimal.  The state of the intersection already exists (green left arrow), it's just a matter of activating one more signal (corresponding green right arrow). 

really, anything that prevents a stop-and-go is a win in my book. 

Agreed, Jake.

Plus, since most people who drive in TN don't stop before making a right turn on red, having a green arrow reduces the amount of time that some yo-yo will rear-end my vehicle.  And, that is definitely worth it, IMHO.

[Hot Rod Hootenanny]

Going back to Zmapper's starting post.  What about LEDs?  Dublin (NW Columbus suburb) has several signals that the arrow changes color (Green to Yellow) within one lense or "ball."  Been in existance for close to a decade now.

[mightyace]

^^^
My first thought on this is, "What about color blind people?"

With multiple balls, you can deduce the aspect from position even if you can't discern the color.

[Brandon]

Going back to Zmapper's starting post.  What about LEDs?  Dublin (NW Columbus suburb) has several signals that the arrow changes color (Green to Yellow) within one lense or "ball."  Been in existance for close to a decade now.

We used to have a ton of 3Ms like that at one time (20 years ago).  All of them were the squared off polarized, directional type ones.  They'd start at green arrow and then change to yellow arrow.  The last one of those bit the dust about 3 years ago.

[US71]

Going back to Zmapper's starting post.  What about LEDs?  Dublin (NW Columbus suburb) has several signals that the arrow changes color (Green to Yellow) within one lense or "ball."  Been in existance for close to a decade now.

We used to have a ton of 3Ms like that at one time (20 years ago).  All of them were the squared off polarized, directional type ones.  They'd start at green arrow and then change to yellow arrow.  The last one of those bit the dust about 3 years ago.

Never saw any in Arkansas, but I think Missouri had a few. I remember a couple that were 5  phases in 4 signals:

O  Red
[ ] Yellow Arrow, Yellow Ball
O  Green
O  Green Arrow

I haven't seen any in a while, though