Split Phasing With No Green Arrows

[Brian556]

I drove through this intersection the other day and was confused as [bleep]. I was turning left at a double left turn, but there was no green arrow, but the oncoming traffic remained stopped. This intersection is apparently split phased with no green arrows. TxDOT contractors installed this signal when the interchange was built, but the City Of Lewisville maintains it. There are several other errors at this intersection including: No DO NOT ENTER signs at the northbound ramp, street name signs say "SH 121", but don't mention that its a business route, route marker assembly on the SB ramp to Denton Tap Rd doesn't have business plagues, and the route marker sign on NB Denton Tap Rd at the split doesn't have a north sign on the right side.

Clearly, nobody knows what they are doing, and they have no business being in charge of traffic control

GSV ( spin around to see the signal issue as well as the signage issues):https://www.google.com/maps/@32.9988902,-96.993361,3a,50.3y,54.8h,89.45t/data=!3m7!1e1!3m5!1sRHrnryMzBWv-WLXtor6sbg!2e0!6s%2F%2Fgeo1.ggpht.com%2Fcbk%3Fpanoid%3DRHrnryMzBWv-WLXtor6sbg%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D318.5196%26pitch%3D0%26thumbfov%3D100!7i16384!8i8192

[jeffandnicole]

I was going to say NJ is famous for traffic lights like this. 

But then I realized instead of offering a solution, you just lumped thousands of professionals as idiots because of one small issue at one intersection that caused you no harm.

[STLmapboy]

I was going to say NJ is famous for traffic lights like this. 

But then I realized instead of offering a solution, you just lumped thousands of professionals as idiots because of one small issue at one intersection that caused you no harm.

From what he described there is a widespread haphazardness around the area.

[Revive 755]

Deerfield Road at the offset intersection with Kipling Place and Kenton Road in Deerfield, IL, has the north and south legs split phased.  The south leg (NB) does not have a green left arrow due to the adjacent crosswalk.

[jeffandnicole]

I looked at historical GSVs here.  They go back to 2007, and the same split phasing is still there.

13 years later, the intersection remains the same. 

When I've helped out with traffic control, I think of it this way: 

When one person screws up, that's their fault. 
When everyone screws up, that's my fault.

If the very same conditions have existed for 13 years, they're fine.  May not be totally ideal, but if at the time of construction the standards allowed for what is shown, they're grandfathered in.  The signage issues are ticky-tacky.  The plaques leading up to the intersection say "Business"  https://goo.gl/maps/3Mcsq4kPRviNXayq5 , and the regular 121 route is no where to be found.

Being that the intersection has existed for 13+ years, and he just found out about it yesterday, I'm inclined to think that the intersection performs well.

[roadman65]

I grew up in NJ I can testify it's the norm there left turns protected but no arrows is common at split phase intersections.


As far as name calling for the one as the many is a normal reaction these days. Not saying it's right but it is normal.

[mrsman]

This signal handles split phasing in a really interesting manner.

https://www.google.com/maps/@39.0154093,-77.0788723,3a,37.5y,298.51h,96.07t/data=!3m7!1e1!3m5!1sOJ_3NcRYWtBk2pDTQtd8Sw!2e0!5s20180801T000000!7i13312!8i6656

Saul Rd and Connecticut Ave , Kensington, MD (2018 view)

WB, you see a doghouse with a sign that says left turn yield to pedestrians on green.  EB, you see the typical 4 aspect signal common for split phasing.  If there are no pedestrians crossing, you see a left arrow during the entire green phase, but where there are pedestrian crossing, you do not see a green arrow for WB phase (which IIRC comes after the EB phase).  This enables both sides of the split phase to be held while the peds are crossing, which saves time overall.  Furthermore, where its inappropriate to have a WB green arrow, the sign is at least an indication that opposing traffic does not have green, since the sign says yield to "pedestrians".

While not a fan of split-phasing generally, due to the inherent delay, this application is at least trying to make best use of the time when Connecticut has a red light.

[RestrictOnTheHanger]

This signal handles split phasing in a really interesting manner.

https://www.google.com/maps/@39.0154093,-77.0788723,3a,37.5y,298.51h,96.07t/data=!3m7!1e1!3m5!1sOJ_3NcRYWtBk2pDTQtd8Sw!2e0!5s20180801T000000!7i13312!8i6656

Saul Rd and Connecticut Ave , Kensington, MD (2018 view)

WB, you see a doghouse with a sign that says left turn yield to pedestrians on green.  EB, you see the typical 4 aspect signal common for split phasing.  If there are no pedestrians crossing, you see a left arrow during the entire green phase, but where there are pedestrian crossing, you do not see a green arrow for WB phase (which IIRC comes after the EB phase).  This enables both sides of the split phase to be held while the peds are crossing, which saves time overall.  Furthermore, where its inappropriate to have a WB green arrow, the sign is at least an indication that opposing traffic does not have green, since the sign says yield to "pedestrians".

While not a fan of split-phasing generally, due to the inherent delay, this application is at least trying to make best use of the time when Connecticut has a red light.

The WB side would be a good candidate for FYA where the left turn signal is green when no pedestrians use the signal, and flashing yellow when they do

[mrsman]

This signal handles split phasing in a really interesting manner.

https://www.google.com/maps/@39.0154093,-77.0788723,3a,37.5y,298.51h,96.07t/data=!3m7!1e1!3m5!1sOJ_3NcRYWtBk2pDTQtd8Sw!2e0!5s20180801T000000!7i13312!8i6656

Saul Rd and Connecticut Ave , Kensington, MD (2018 view)

WB, you see a doghouse with a sign that says left turn yield to pedestrians on green.  EB, you see the typical 4 aspect signal common for split phasing.  If there are no pedestrians crossing, you see a left arrow during the entire green phase, but where there are pedestrian crossing, you do not see a green arrow for WB phase (which IIRC comes after the EB phase).  This enables both sides of the split phase to be held while the peds are crossing, which saves time overall.  Furthermore, where its inappropriate to have a WB green arrow, the sign is at least an indication that opposing traffic does not have green, since the sign says yield to "pedestrians".

While not a fan of split-phasing generally, due to the inherent delay, this application is at least trying to make best use of the time when Connecticut has a red light.

The WB side would be a good candidate for FYA where the left turn signal is green when no pedestrians use the signal, and flashing yellow when they do

I would agree with you, but MD doesn't incorporate the FYA.  They have a flashing red arrow, but its really not the same.

[Super Mateo]

There are split phases at the intersection of 87th, Ridgeland, State, and Narragansett on the border of Oak Lawn and Burbank, IL.  Each approach has its own phase, except for both directions on 87th.  I know what to do because I'm very familiar with this intersection, but it would be nice if they added left arrows for clarity.  It's not really a safety issue, but left arrows would help, especially on Ridgeland, where it's not made clear traffic on Narragansett or State is being held.

[fwydriver405]

This happens a lot around my area with older installations, especially non-NHDOT maintained signals in New Hampshire. In my case, sometimes an option lane is added later on to the existing configuration, with the previous phasing being protected/permissive, making the intersection from single to double left, which 99.9% in my area forces split phasing at these intersections:

Maine: Bangor, Biddeford, Sanford, Wells
New Hampshire: Somersworth*, Dover

*Notice the red right arrow on the Somersworth example. You would think it would be RA-YA-GA for a right turn overlap, but nope, it's RA-Y-G with no overlap! The intersection also runs in an exclusive ped phase. Unless they took out the overlap a long time ago, seems pointless to have that configuration...

[SectorZ]

I have a few of these around me, and they're all ancient and should have been replaced years ago.

One is Lowell MA and is being replaced and hopefully with either correct phasing and/or signals.

One in Wilmington is a mess because the town of Wilmington is a mess. https://goo.gl/maps/VpBvpn5J42DmVXoz9
As you can see eastbound on 129 a left/straight option lane was recently striped with a straight arrow. When I asked them about it in late 2019, they "fixed" it by adding a left turn arrow between the straight arrows.

[kphoger]

I've mentioned this one on some thread or another in the past, but...

Federal highway
Four lanes, divided
Route from the 3rd largest (381k metro) to the largest (923k metro) city in the state
Route also to the 3rd largest metro area (4.48 million) in the nation
14,330 AADT (2019)
24% trucks and buses
One signal per direction
Split phasing with no arrows

https://goo.gl/maps/LCVPURZPgfkeGD4CA

[STLmapboy]

I have a few of these around me, and they're all ancient and should have been replaced years ago.

One is Lowell MA and is being replaced and hopefully with either correct phasing and/or signals.

One in Wilmington is a mess because the town of Wilmington is a mess. https://goo.gl/maps/VpBvpn5J42DmVXoz9
As you can see eastbound on 129 a left/straight option lane was recently striped with a straight arrow. When I asked them about it in late 2019, they "fixed" it by adding a left turn arrow between the straight arrows.

I don't have enough MA context to understand the "Wilmington is a mess" joke. Is it a poorly run area or is the town just bad at installing things?

[STLmapboy]

I've mentioned this one on some thread or another in the past, but...

Federal highway
Four lanes, divided
Route from the 3rd largest (381k metro) to the largest (923k metro) city in the state
Route also to the 3rd largest metro area (4.48 million) in the nation
14,330 AADT (2019)
24% trucks and buses
One signal per direction
Split phasing with no arrows

https://goo.gl/maps/LCVPURZPgfkeGD4CA

Sad thing is this was installed in 2017/18 and looks like a 90s TX install.