Traffic signal

[roadman65]

^^ MUTCD allows for 2 kinds of drawbride signals - the standard RYG signal that shows green when the bridge is not in operation, and 2 vertical red beacons separated by a stop here on red sign which flash alternately when the drawbridge is in operation and dark when not.

And Newark, NJ used to used standard red yellow green heads, but flashed them when the bridges were lowered. Don’t know if they still flash. Heck don’t even know if large vessels use the Passaic River anymore through Newark as the NJ 3 drawbridge in Clifton ( 5 or so miles upstream from Newark) was removed for a fixed span a while ago. 

[SignBridge]

Don't forget about rail road signals. They rest in dark while having no amber either.

Some older drawbridges in Florida used red flashers similar to railroad flashers. They would be dark until the bridge tender operates the bridge raising procedures.

Railroad signals are a separate category of signals. Yes, they rest-in-dark but are completely different in appearance from standard traffic signals.

[roadman65]

I see the gate lowering process on CSX crossings require separate lowering of opposing gates. The right side comes down before the left.  I’m guessing that’s either CSX or FDOT, and not the MUTCD implementing this to avoid vehicles getting trapped between gates, especially when many drivers are trying to spare shock absorbers abuse or wheel alignment costs by creeping across the tracks.

I live in Florida and been noticing this new process ar local grade crossings.

[chrisg69911]

^^ MUTCD allows for 2 kinds of drawbride signals - the standard RYG signal that shows green when the bridge is not in operation, and 2 vertical red beacons separated by a stop here on red sign which flash alternately when the drawbridge is in operation and dark when not.

And Newark, NJ used to used standard red yellow green heads, but flashed them when the bridges were lowered. Don't know if they still flash. Heck don't even know if large vessels use the Passaic River anymore through Newark as the NJ 3 drawbridge in Clifton ( 5 or so miles upstream from Newark) was removed for a fixed span a while ago.

There's usually a 30ft clearance under the bridge, but it doesn't even matter since the union ave bridge after that is a low fixed span. The commerical traffic on the passaic river is zero, especially after the industry in Passaic slowed down

[roadman65]

^^ Georgia requires 2 red turn arrows for protected left turns, but is usually done by 2 signal heads, though a single T-head with 2 red arrows is occasionally used to meet that requirement.  And MUTCD calls for a minimum 8' separation (center to center).

I believe the eight-foot separation rule between signal heads only applies to the two circular-green heads for the thru movement. I checked this out after observing several installations in New York City where the left or right turn signal head was hung right next to the thru movement head on mast-arms, separated by only a couple of feet. It's getting to be a common sight in Midtown Manhattan. 

https://goo.gl/maps/brfS4P9euJtUestH6
They got it right at this intersection. The two heads are at least 8 feet apart.

[roadman65]

https://www.flickr.com/photos/54480415@N08/52082265243
What are these pole bases called?

In NJ and NYC they seem to be the norm. I always assumed they're breakaway just like freeway light poles are to break free if a vehicle hits one.

[jakeroot]

Could anyone say for sure if this new signal is compliant? The shared signal seems odd.

WSDOT resignalized the intersection of US-101 and WA-105, just south of the Chehalis River in Aberdeen. The project added a crosswalk (the one in the foreground).


US-101 / WA-105 traffic signal by Jacob Root, on Flickr

[Big John]

The side signal counts toward the 2-signal requirement.

[SkyPesos]

Could anyone say for sure if this new signal is compliant?

WSDOT resignalized the intersection of US-101 and WA-105, just south of the Chehalis River in Aberdeen. The project added a crosswalk (the one in the foreground).


US-101 / WA-105 traffic signal by Jacob Root, on Flickr

What's the reason for a protected left turn using an option lane here? Sounds counterintuitive to me (though MoDOT does it a bit in the STL area too).

[jakeroot]

The side signal counts toward the 2-signal requirement.

I was thinking the shared signal, sorry. Should have been more specific in my OP.

What's the reason for a protected left turn using an option lane here? Sounds counterintuitive to me (though MoDOT does it a bit in the STL area too).

This was my confusion with the setup. I don't know why they don't use either a double left with a single through lane on the right, or a single left (probably FYA) with two through lanes on the right. The whole thing could have still been signalized to allow for a pedestrian crossing. But instead they create this weird middle lane situation where literally zero people will ever use it. Unless they get lucky and time it perfectly.

[mrsman]

The side signal counts toward the 2-signal requirement.

I was thinking the shared signal, sorry. Should have been more specific in my OP.

What's the reason for a protected left turn using an option lane here? Sounds counterintuitive to me (though MoDOT does it a bit in the STL area too).

This was my confusion with the setup. I don't know why they don't use either a double left with a single through lane on the right, or a single left (probably FYA) with two through lanes on the right. The whole thing could have still been signalized to allow for a pedestrian crossing. But instead they create this weird middle lane situation where literally zero people will ever use it. Unless they get lucky and time it perfectly.

My only response to the middle lane is that perhaps there are times when traffic is heavy enough that warrant the two lanes.  There could be one part of the day when the left turn is the heavier movement, and one time of day when the striaght is the heavier movements.

So under normal operation, it seems that the middle lane is mainly useful for left turning traffic, since a person waiting to turn left will need to wait for the green, and straight traffic will just take the right lane which will always be green, except when a pedestrian is crossing.  However, if there is a backup in the right lane - will it not be better to sty in the middle lane (to flow straight into the left lane of WA 105) even if you are behind someone turning left?  How about if there is noboby in front of you?

The situation can speak to any situation where there is a middle option lane that is not split phasing.  (Obviolulsy with split phasing, green stragiht and green arrow are lit at exactly the same time.)  There will be some times when people traveing in the option lane will be blocked by people ahead of them, but having the option helps to even out the flow of traffic.

Now in this specific situation, it doesn't seem necessary as the 101 movement is much heavier, so it might as well be: Left, left, straignt.  But down below on Bowery at Manhattan Bridge, with far heavier traffic and a heavy left movement in the afternoon and a heavy straight movement in the mornings (and no room to widen the street), the option lane (with a permissive left) is the only reasonable compromisse:

https://www.google.com/maps/@40.7167779,-73.995796,3a,33.3y,216.92h,88.73t/data=!3m6!1e1!3m4!1sya5VTAlXavIA-jf4cwtNtw!2e0!7i16384!8i8192?entry=ttu

Now it is true that with permissive lefts, it is possible for someone in the middle lane to make their left on a regular green (and not hold up traffic behind them) but realistically with NYC traffic, that is rare and so effectively people are only turning at the lagging left arrow.  And if you are in the middle lane, you can go either left or straight.

[roadfro]

Could anyone say for sure if this new signal is compliant? The shared signal seems odd.

WSDOT resignalized the intersection of US-101 and WA-105, just south of the Chehalis River in Aberdeen. The project added a crosswalk (the one in the foreground).


US-101 / WA-105 traffic signal by Jacob Root, on Flickr

I don't think the MUTCD envisions scenarios like this, so compliance might not be achievable... But I would think that it's not really compliant, because you have a through movement (the shared lane) where there is only one signal head for the through movement–the right lane signals being controlled separately doesn't count (in my opinion). Perhaps if both the shared signal and the left turn signal were both using circular red indications, it would be closer to compliant...


The setup is a bit odd though. With the crosswalk on this near side, all vehicular traffic has to stop when a pedestrian is crossing. I keep thinking that they could have put the pedestrian crossing on the far side instead–this would have allowed both directions of US 101 to go at the same time as pedestrians crossing the WA 105 leg.

It appears the only reason that the crosswalk was put on the near (west) side is to provide a signalized crossing for the Chehalis River Trail. However, it seems like maybe they could have routed the trail to cross underneath the bridge instead, which would likely be better for the trail users than needing to cross the highway at grade.

[jeffandnicole]

Could anyone say for sure if this new signal is compliant? The shared signal seems odd.

WSDOT resignalized the intersection of US-101 and WA-105, just south of the Chehalis River in Aberdeen. The project added a crosswalk (the one in the foreground).


US-101 / WA-105 traffic signal by Jacob Root, on Flickr

I don't think the MUTCD envisions scenarios like this, so compliance might not be achievable... But I would think that it's not really compliant, because you have a through movement (the shared lane) where there is only one signal head for the through movement–the right lane signals being controlled separately doesn't count (in my opinion). Perhaps if both the shared signal and the left turn signal were both using circular red indications, it would be closer to compliant...


The setup is a bit odd though. With the crosswalk on this near side, all vehicular traffic has to stop when a pedestrian is crossing. I keep thinking that they could have put the pedestrian crossing on the far side instead–this would have allowed both directions of US 101 to go at the same time as pedestrians crossing the WA 105 leg.

It appears the only reason that the crosswalk was put on the near (west) side is to provide a signalized crossing for the Chehalis River Trail. However, it seems like maybe they could have routed the trail to cross underneath the bridge instead, which would likely be better for the trail users than needing to cross the highway at grade.

Per https://mutcd.fhwa.dot.gov/htm/2009/part4/part4d.htm#figure4D09 , Standard 01 C, "The shared signal face shall always simultaneously display the same color of circular indication that the adjacent through signal face or faces display.

So if I understand this correctly, this light *shouldn't* be compliant because the option lane must have a green thru signal whenever the thru lane has a green signal.

Why I highlight shouldn't: In the standard they state "circular indication".  At the intersection, the right lane is using a straight up arrow.  I think Washington is trying to sidestep the intent of the guidance here by claiming the standard doesn't apply since the right lane is using a straight arrow green, not a circular green.

[roadfro]

^ I think you're right, both with the citation of the shared signal face standard that applies (which I was too lazy to look for yesterday) and the interpretation on how WA is sidestepping the intent of the standard.

[jakeroot]

Thanks for the replies, everyone.

Now in this specific situation, it doesn't seem necessary as the 101 movement is much heavier, so it might as well be: Left, left, straignt.  But down below on Bowery at Manhattan Bridge, with far heavier traffic and a heavy left movement in the afternoon and a heavy straight movement in the mornings (and no room to widen the street), the option lane (with a permissive left) is the only reasonable compromisse:

https://www.google.com/maps/@40.7167779,-73.995796,3a,33.3y,216.92h,88.73t/data=!3m6!1e1!3m4!1sya5VTAlXavIA-jf4cwtNtw!2e0!7i16384!8i8192?entry=ttu

Now it is true that with permissive lefts, it is possible for someone in the middle lane to make their left on a regular green (and not hold up traffic behind them) but realistically with NYC traffic, that is rare and so effectively people are only turning at the lagging left arrow.  And if you are in the middle lane, you can go either left or straight.

I think this kind of setup (Bowery approach to Manhattan Bridge) would have been a good solution here. Unfortunately, WSDOT would be unlikely to ever intentionally use a permissive setup with more than one lane; I say intentionally because double left turns on red are common for on-ramps, and I've never seen any signed for no-turn-on-red.

The setup is a bit odd though. With the crosswalk on this near side, all vehicular traffic has to stop when a pedestrian is crossing. I keep thinking that they could have put the pedestrian crossing on the far side instead–this would have allowed both directions of US 101 to go at the same time as pedestrians crossing the WA 105 leg.

It appears the only reason that the crosswalk was put on the near (west) side is to provide a signalized crossing for the Chehalis River Trail. However, it seems like maybe they could have routed the trail to cross underneath the bridge instead, which would likely be better for the trail users than needing to cross the highway at grade.

I noticed this as well, it is pretty frustrating. I hope it's an all-way walk, at least.

^ I think you're right, both with the citation of the shared signal face standard that applies (which I was too lazy to look for yesterday) and the interpretation on how WA is sidestepping the intent of the standard.

I'm going to agree with this assessment as well.

Reminds me of how Japan will signalize a protected turn: red orbs, but with green arrows for the directions that can go. Example.

[roadman65]

https://www.flickr.com/photos/54480415@N08/53179253649
Check this one out on the NB I-49 Exit 86 ramp in Bentonville, AR. Two mast arms in opposing directions.

[freebrickproductions]

https://www.flickr.com/photos/54480415@N08/53179253649
Check this one out on the NB I-49 Exit 86 ramp in Bentonville, AR. Two mast arms in opposing directions.

You see that on occasion. University Drive/US 72 here in Huntsville, AL, used to have a 4-way mast-arm in the median of it just east of Research Park Boulevard/AL 255 prior to the site of Madison Square Mall being redeveloped into MidCity Huntville.

[jakeroot]

University Drive/US 72 here in Huntsville, AL, used to have a 4-way mast-arm in the median of it just east of Research Park Boulevard/AL 255 prior to the site of Madison Square Mall being redeveloped into MidCity Huntville.

Kind of unrelated, but I find it quite peculiar how the left turn (slightly west of the original signal) was unsignalized, despite its very close proximity to the main signal.

[Dirt Roads]

University Drive/US 72 here in Huntsville, AL, used to have a 4-way mast-arm in the median of it just east of Research Park Boulevard/AL 255 prior to the site of Madison Square Mall being redeveloped into MidCity Huntville.

Kind of unrelated, but I find it quite peculiar how the left turn (slightly west of the original signal) was unsignalized, despite its very close proximity to the main signal.

It is even stranger how the left turn signals (slightly east of the original signal) are mounted on the mast that is entirely over the opposing lanes.  One of those signal does line up with the leftmost turn lane, but this doesn't look Kosher.

[steviep24]

^
Then there's this strange assembly in downtown Rochester, NY. They could have used one mast arm for that. Both signal heads are for the same approach.

[PColumbus73]

https://www.flickr.com/photos/54480415@N08/53179253649
Check this one out on the NB I-49 Exit 86 ramp in Bentonville, AR. Two mast arms in opposing directions.

In North Carolina, they seem to like using the butterfly mast arms for their superstreet intersections.

https://www.google.com/maps/@34.2158859,-78.0189599,3a,89.9y,352.37h,91.42t/data=!3m6!1e1!3m4!1swZdVPr4678ep7z1QXKbDfg!2e0!7i16384!8i8192?entry=ttu

[roadman65]

https://www.flickr.com/photos/54480415@N08/53199779885/in/dateposted-public/
Here is one in Hutchinson, KS using all three direction arrows rather than a green ball.  Though the side mount is a green ball.

Although I know what is being done here using the right overhead the way they are, but it still seems odd seeing it this way.

[SignBridge]

https://www.flickr.com/photos/54480415@N08/53199779885/in/dateposted-public/
Here is one in Hutchinson, KS using all three direction arrows rather than a green ball.  Though the side mount is a green ball.

Although I know what is being done here using the right overhead the way they are, but it still seems odd seeing it this way.

That looks ridiculous. A green-ball would have been better for the right-overhead.

[kphoger]

https://www.flickr.com/photos/54480415@N08/53199779885/in/dateposted-public/
Here is one in Hutchinson, KS using all three direction arrows rather than a green ball.  Though the side mount is a green ball.

Although I know what is being done here using the right overhead the way they are, but it still seems odd seeing it this way.

That looks ridiculous. A green-ball would have been better for the right-overhead.

Perhaps.  Yet it wouldn't convey the same information.  A green left arrow tells the driver that his turn is protected.  If we assume the driver is only paying attention to the signal in front of his lane (which a policy of signal head per lane seems to assume), then a green ball wouldn't convey that same information.

Which makes me wonder...  Is this split-phasing only?  I don't see how, given the stoplight set up, opposing traffic could have a green light at the same time.

[roadman65]

https://www.flickr.com/photos/54480415@N08/53199779885/in/dateposted-public/
Here is one in Hutchinson, KS using all three direction arrows rather than a green ball.  Though the side mount is a green ball.

Although I know what is being done here using the right overhead the way they are, but it still seems odd seeing it this way.

That looks ridiculous. A green-ball would have been better for the right-overhead.

Perhaps.  Yet it wouldn't convey the same information.  A green left arrow tells the driver that his turn is protected.  If we assume the driver is only paying attention to the signal in front of his lane (which a policy of signal head per lane seems to assume), then a green ball wouldn't convey that same information.

Which makes me wonder...  Is this split-phasing only?  I don't see how, given the stoplight set up, opposing traffic could have a green light at the same time.

It's split phased. I drove the set up last week.

Also a green ball with green left would suffice in the right lane. Being it's split phased, it would convey that both lanes are indeed protected.

In my home state a doghouse would be used in this set up for the right signal head. Even with the yellow left and yellow balls working together, it wouldn't matter the redundant use of two different ambers.