Double left turns with permissive phasing

[mrsman]

Unsure if this counts, but this double (YoG-pt+pm) left turn in San Francisco is a bit strange - a dedicated left turning lane for bicycles (to turn into the protected bike lane), and a shared left-thru lane for motor vehicles (into the other lanes). Advanced green for NB Scott St, then the permissive phase for both approaches. The SB approach is thru-right for bikes, and right turn only for moter vehicle traffic. Scott and Fell Streets:

GSV: https://www.google.com/maps/@37.7739963,-122.4358715,3a,29.9y,349.72h,84.29t/data=!3m7!1e1!3m5!1sjiSDRsUVatHwIWzVwz99cQ!2e0!5s20220301T000000!7i16384!8i8192?entry=ttu
Overview: https://www.google.com/maps/@37.774189,-122.4359471,75m/data=!3m1!1e3?entry=ttu

I guess if it were up to this black Honda Accord, there wouldn't be any question that it qualifies!

I am actually willing to count this. It's really intriguing, I'm sure most places would have some kind of exclusive phasing for this approach instead of having it run concurrent with vehicular traffic.

It's almost like a purposeful version of a lane-split turn for a motorcyclist. Here in Japan, where like California it is also legal to ride between lanes of traffic, it's not unusual to be waiting to turn across traffic when a motorcyclist (usually scooter) will come up between traffic and wait next to you while you're also waiting to turn. It'll be a single lane turn (right turn in Japan), but it becomes a sort of double permissive turn with the motorcyclist also hanging out there in the middle waiting with you. As far as I can tell, that's basically what might happen in the SF example, although there is at least a designated cycle lane.

A bit of a weird one.  I'd say that the bike left turn doesn't have to turn against car traffic, only against peds and oncoming bikes. If one were to ignore the oncoming bikes, this is like a left from one way to one way as the bikes make their left into the lane most adjacent to the curb on Fell.  So really only the cars have to make a permissive left against traffic (opposing vehicles making the right from Scott to Fell).

A very unique example!

[andrepoiy]

Colorado Springs, CO:



Link: https://maps.app.goo.gl/Rj11AfwDRnW3sLu37

[Big John]

I just passed Lombardi Ave at I-41 where WisDOT  is currently changing WB to SB dual left from turn on arrow only to a FYA.

[fwydriver405]

Found a brand new, double permissive FYA lagging left (with two left turn lanes) in Dorchester (Boston), Massachusetts at the intersection of Morrissey Blvd and Freeport St on the SB Freeport St approach. Not sure if this was a MassDOT or DCR installation, as they recently redid the intersection.

Unlike the other double permissive left on Atlantic Ave and Congress St, on the SB approach, where it's only double permissive left due to left turn on red, this one had a second left turn lane added and the PPLT phase retained via FYA. Unfortunately the NB Freeport St approach is yellow trapped, however I didn't get to get a chance to look at the opposing signals.

EDIT, photo and video of the intersection:



https://www.youtube.com/watch?v=j6d62fYJXEA

[jakeroot]

Found a brand new, double permissive FYA lagging left (with two left turn lanes) in Dorchester (Boston), Massachusetts at the intersection of Morrissey Blvd and Freeport St on the SB Freeport St approach. Not sure if this was a MassDOT or DCR installation, as they recently redid the intersection.

Unlike the other double permissive left on Atlantic Ave and Congress St, on the SB approach, where it's only double permissive left due to left turn on red, this one had a second left turn lane added and the PPLT phase retained via FYA. Unfortunately the NB Freeport St approach is yellow trapped, however I didn't get to get a chance to look at the opposing signals.

EDIT, photo and video of the intersection:

[clipped]

Thank you for posting! This is one of the more interesting ones I've seen lately.

Some of the GSV imagery seems to suggest that some drivers were already turning left from the through lane. Or possibly this was a permitted movement, and I just can't find any signage to prove it.

The new far-left signal is great. While I'm a proponent of making this standard for all approaches, it's nice they added it here as before, there was no visible signal while waiting.

While this is cool to see, especially with the markings in the intersection showing where drivers to wait when turning, the fact that NB Freeport is still allowed turn left onto Morrissey Blvd is quite odd. I would think detouring those cars via Mill or Everdean would create less of that unusual left turn overlap situation occurring in the video.

As an aside, I assume this is the only double permissive FYA setup in Massachusetts.

[jakeroot]

Found a new triple permissive turn, though with a twist.

Outside of Fukuoka, Japan, in the city of Chikushino, there is a triple permissive right turn at the Harizuri Intersection. The right two right-turn lanes make a 90-degree turn onto the ramp to National Route 3, whilst the left right-turn lane makes a shallower turn onto a local road (Fukuoka Prefectural Route 112).
As is tradition in Japan, at complex intersections, colors are used to guide traffic through. The lanes turning towards National Route 3 are blue, and the lane to Route 112 is green. Through traffic has red markings.

Apparently this intersection has a fairly high crash rate (intersection "D" on the list).

Here's my render showing how it flows:


Harizuri Intersection, Chikushino by Jacob Root, on Flickr

[Revive 755]

WB 5th Street at MO 109 in Eureka has one.

[jakeroot]

I was perusing Honolulu on Google Street View when I happened upon this intersection near the Capitol Building:

https://www.google.com/maps/@21.3050335,-157.8527162,62m/data=!3m1!1e3?entry=ttu

Northbound Alapai St has a triple left turn onto S Beretania St. There is an oncoming single right turn lane. Judging by the Street View imagery, both approaches have green signals at the same time (the linked imagery is old, but I picked it because it shows the situation best; more recent imagery still shows it behaving this way).

In terms of signage, there is no supplemental signage or unusual phasing. Northbound Alapai has "no left on red" signs, and southbound must turn right, but otherwise it's just two streets meeting with green lights.

Based on normal road rules, with left turns yielding to right turns, this is technically a three-lane permissive left turn. But in practice, I have to assume that the left turn massively overwhelms the right turn, to the point where the right turn is the one doing the yielding. But based purely on law...well, you get my point.

What say you guys, is this technically a permissive triple left turn? Or is there some other law taking precedent in this situation that I'm not aware of?

[freebrickproductions]

Spotted this down in Opelika, AL, recently:
https://www.google.com/maps/@32.6436497,-85.3530282,3a,49y,271.31h,77.08t/data=!3m7!1e1!3m5!1sjqohyMkmDPJErJb6D9R2Gw!2e0!5s20221101T000000!7i16384!8i8192?coh=205409&entry=ttu

I have to wonder if it's the only double FYA set-up in the state, outside of the permissive-only pairs in downtown Huntsville.

Slightly unrelated note and it's too new for street view, but Franklin, TN, has replaced these double right-turn doghouses with a double right-turn FYA set-up. Are there any other set-ups like that in the US?

[mrsman]

Slightly unrelated note and it's too new for street view, but Franklin, TN, has replaced these double right-turn doghouses with a double right-turn FYA set-up. Are there any other set-ups like that in the US?

Could you provide more detail.  During what phase is the FYA lit up?  Is the NTOR restriction still present?

I can't recall any double FYA for right turns, but I am aware that in some localities they are used for "semi-protected" rights, depending on the context.

Obviously, a protected right gets a green arrow.  This usually occurs when: 1) adjacent traffic has a green orb and no pedestrians are crossing in the path of right turns or 2) at the same time of the corresponding left turns.

Tucson, AZ a number of years ago replaced green arrows with FYAs where the left turns allow u-turns because of the possibility that u-turns could conflict with the right turns.  This is semi-protected, protected from all traffic except the u-turners.  CA generally does not allow right green arrows if there is a permissible conflicting u-turn, but other states do (like here in MD).  I wish they would adopt the Tucson approach because the right is not completely protected if u-turns are allowed and right turners should yield to the u-turners if they are present.

This intersection in Los Angeles, Robertson Blvd NB to Venice Blvd EB, has a FYA signal controlling the single right turn lane.  A green right arrow is lit when the corresponding WB to SB left has a green left arrow.   The FYA is lit when adjacent traffic can go straight on a green straight arrow, but pedestrians are crossing at the crosswalk.  There was a fatal accident here years ago, and it was believed that the FYA control could help.  Even though this is a wide street, there are significant pedestrian crossings here as a high school is a few blocks away and a transit station for the Metro E line is one block away.  This is also semi-protected, the right turn here is protected from all except the adjacent pedestrians.

https://www.google.com/maps/@34.0279854,-118.3900596,3a,23.8y,336.94h,87.3t/data=!3m7!1e1!3m5!1si7aVV5fvav52u4OwXnIT7Q!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fpanoid%3Di7aVV5fvav52u4OwXnIT7Q%26cb_client%3Dmaps_sv.share%26w%3D900%26h%3D600%26yaw%3D336.9424440044513%26pitch%3D2.6958146141220567%26thumbfov%3D90!7i16384!8i8192?coh=205410&entry=ttu

[freebrickproductions]

Could you provide more detail.  During what phase is the FYA lit up?  Is the NTOR restriction still present?

Honestly, I'd have to go out and double check on the NTOR restriction (I want to say it's still there though?), along with watching to see how they cycle. I wouldn't be too surprised if the flashing yellows come-on during the clearance phase of the pedestrian crossing there though.

[freebrickproductions]

Okay, was able to snag some photos and video (that to be posted to YouTube later) of the double right turn FYAs in Franklin, TN, @mrsman. The NTOR restriction is also still present. If not pedestrians are wanting to cross, the signals operate as RYG protected right turn signals, turning green when the thru-signals turn green, and remaining green when the left-turn off of westbound TN 96 gets its protected turn. If a pedestrian wishes to cross, however, the signals remain red during the walk phase of the pedestrian signals, and then drop to a flashing yellow for the clearance phase of the pedestrian signals. They then go to green for the protected left turn off of TN 96 westbound after.

IMG_7513 by freebrickproductions, on Flickr

IMG_7516 by freebrickproductions, on Flickr

[mrsman]

Very interesting.  Thanks for the follow up.

So the setup essentially provides a protected right: 1) at the same time as adjacent straight traffic if no pedestrians are crossing and 2) when the corresponding left turn is protected.  It gives a permitted right with caution (FYA) at the same time as straight traffic if there are pedestrians crossing, while also implelmenting a leading pedestrian interval (giving pedestrians a legally protected crossing during the walk phase due to the red arrow). 

I think this is a first step at making pedestrians who cross somewhat safer.  NOw the land use is not very pedestrian oriented, not a surpise in an exurban community, but that doesn't mean that there aren't folks who may still want to make the relatively short walk from a hotel or apartment to a grocery store.

Very similar to the operation of the traffic signal at Venice/Robertson in L.A. that I mentioned earlier.

Here is further info:

https://la.streetsblog.org/2015/07/06/dangerous-intersection-of-venice-and-robertson-gets-a-flashing-yellow-signal

[freebrickproductions]

It's definitely a very smart idea. My hometown of Huntsville had a similar thought in downtown where all traffic is required to turn right or turn left at an intersection. As the pedestrian crossings there automatically cycle with the traffic lights, if the city were to use green arrows, it would conflict with the pedestrian crossings. However, if they were to use green balls (as they did previously), someone might see that and think they could go straight into oncoming traffic. As such, the city instead uses permissive-only FYA signals:
https://www.google.com/maps/@34.7303758,-86.5859832,3a,27.8y,58.62h,94.75t/data=!3m6!1e1!3m4!1s_aRUKRjTlzM4s74twv-R1g!2e0!7i16384!8i8192?coh=205409&entry=ttu

[mrsman]

Green arrows would not be allowed unless the turn were completely protected (except for the possible u-turn conflict that can occur with a right turn).  While green orbs were the standard for situations as above, I do like the FYA as it still provides a warning to look out for a possible conflict, while at the same time acknowledging that the straight movement is not at all available.

[jakeroot]

In the Phoenix area: Loop 303 at Lake Pleasant Pkwy, the double left turns onto the on-ramps are both permissive (5-section towers). When the interchange opened in the late 2000s, the left turns were protected-only, but were converted (likely due to low traffic numbers) to protected-permissive in 2015. Though the double left turns were maintained.

Approach 1: https://maps.app.goo.gl/Yg8w2g32yUbot3kH9
Approach 2: https://maps.app.goo.gl/ohUv3vGiJ338J65K7

[mrsman]

In the Phoenix area: Loop 303 at Lake Pleasant Pkwy, the double left turns onto the on-ramps are both permissive (5-section towers). When the interchange opened in the late 2000s, the left turns were protected-only, but were converted (likely due to low traffic numbers) to protected-permissive in 2015. Though the double left turns were maintained.

Approach 1: https://maps.app.goo.gl/Yg8w2g32yUbot3kH9
Approach 2: https://maps.app.goo.gl/ohUv3vGiJ338J65K7

I give Phoenix a lot of credit for going to the permissive approach here, given the low traffic numbers.

While this thread is focused on permissive double lefts, and knowing that many jurisdictions are very reluctant from allowing this situation to be anything other than protected only, I feel that it's a good thing to consider going to premissive lefts when traffic is not heavy, so as to avoid the delays that are inherent in waiting for the green arrow, when traffic is light and there are a lot of gaps.  If the left turn is not very heavy, it would certainly be preferred to favor a single left turn lane with a permissive green arrow, than a double left turn with a protected only green arrow.  In a situation such as the above, it would be perfectly OK to paint out (with stripes) one of the left turn lanes in each direction as not being needed for the time being and then allowing the double left when development and traffic would necessitate it.

And I think the opposite is also true.  COVID (and the resulting WFH) has changed a lot of traffic patterns.

This left turn near me is a double left with protected only lefts.

https://www.google.com/maps/@39.0631603,-77.0550609,3a,34.4y,125.6h,87.79t/data=!3m7!1e1!3m5!1s2-zB8ScacdlmV_xk99sulw!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fcb_client%3Dmaps_sv.tactile%26w%3D900%26h%3D600%26pitch%3D2.2124355140728085%26panoid%3D2-zB8ScacdlmV_xk99sulw%26yaw%3D125.60033694378508!7i16384!8i8192?coh=205410&entry=ttu&g_ep=EgoyMDI0MDkxOC4xIKXMDSoASAFQAw%3D%3D

 I would argue that the current traffic patterns would favor a single left lane with permissive lefts.  The double left heads to a side street that provides some local connection, but generally any traffic that is continuing on the side street must be in the left lane.  The right lane forces a right at the next block and is generally only useful to access the Metro station.  Now the busiest time for this left would be morning rush as people head to the station (but many people don't even need to make this left as there is a second garage across Georgia Ave that wouldn't even necessitate the left turn in the first place).  But traffic on Georgia Ave is heavy SB in the morning and NB in the afternoon, hence there are a lot of gap opportunities to make this left.  And there is far less suburban use of the Metro system today than there was 5 years ago as a result of the WFH, so this left is seeing a lot less demand than it used to.

So it would be nice to convert this to a permissive left, even if they take out one of the left turn lanes to enable them to do so.

[fwydriver405]

Found another double permissive left with circular greens by accident, this time in Amherst, New Hampshire at the Route 101A at Walmart/Dunkin Donuts driveway.

Given this is a NHDOT maintained signal, I'm probably guessing this might have been an oversight, especially if the lanes were reconfigured to the present setup. GSV suggests this phasing has been in place since August 2007. Notice how the centre lane of the Walmart approach has no thru movement to the Dunkin Donuts, however, if you look at previous GSVs, the thru movement is present, so guessing somebody forgot to paint such movement arrow.

[fwydriver405]

Just gonna dust off this thread. Looking for some input from those familiar with Maryland.

I found a left turn in Silver Spring (Route 650 onto Columbia Pike). It's a dual left turn with a flashing red arrow, with turns permitted after a full stop.

I've read before that flashing red arrows are pretty ubiquitous in Maryland (versus flashing yellow arrows). I can tell from Street View that many single lefts have FRAs, but not many dual lefts.

Anyone know how often Maryland installs dual left flashing red arrows?

Here is the Gmaps link to the intersection below: https://goo.gl/Lr4gDD -- according to Historic Aerials, the second left turn lane was added in 2005.

On the way to Towson University yesterday to the hotel, I passed by a very similar setup to the one listed above on Dulaney Valley Rd SB to I-695 EB in Towson, which is about 64 km (40 mi) from the one above in the quoted post (which I first thought was the same signal when I saw it). If I've got time today or tomorrow, I'll have to check out this signal since it's not too far walking distance from our hotel...

[fwydriver405]

As promised above, I went to videotape the above signal and how it operates yesterday. Operates as a two phase signal - NB thrus then the SB protected left, similar to the Silver Springs example.

[Tendies]

In the Phoenix area: Loop 303 at Lake Pleasant Pkwy, the double left turns onto the on-ramps are both permissive (5-section towers). When the interchange opened in the late 2000s, the left turns were protected-only, but were converted (likely due to low traffic numbers) to protected-permissive in 2015. Though the double left turns were maintained.

Approach 1: https://maps.app.goo.gl/Yg8w2g32yUbot3kH9
Approach 2: https://maps.app.goo.gl/ohUv3vGiJ338J65K7

These have since been reverted back to protected only within the last year or two.

Peoria still has quite a few PPLT double lefts, although they all have significantly less traffic on the opposing approach. More often than not, the FYA often doesn't even come on.

83/grand/peoria: There's two stub lights at this set of intersections. I scrolled around a bit but I couldn't find a street view where the FYA was active on either intersection. They both face a parking lot
https://www.google.com/maps/@33.5815735,-112.2363371,3a,30y,44.3h,84.61t/data=!3m8!1e1!3m6!1sCM8e1J41i0NknRJ25k-IXg!2e0!5s20190501T000000!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fcb_client%3Dmaps_sv.tactile%26w%3D900%26h%3D600%26pitch%3D5.385544873685674%26panoid%3DCM8e1J41i0NknRJ25k-IXg%26yaw%3D44.301706534121365!7i16384!8i8192?entry=ttu&g_ep=EgoyMDI1MDUyOC4wIKXMDSoASAFQAw%3D%3D

Rio Vista/Thunderbird: A somewhat busy light that has a busy gas station, a large park, warehouses, and a few businesses on one side, and apartments on the other. 90% of traffic is southbound, where most traffic makes a left to head towards the freeway. Northbound traffic is surprisingly minimal in comparison. If the situation arises where a lot of southbound cars get an FYA, they will often dominate over the one or two cars going north.
https://www.google.com/maps/@33.6102344,-112.2502193,3a,37.5y,195.84h,83.65t/data=!3m8!1e1!3m6!1sMLw6N-4LJATrLh344-zoUA!2e0!5s20211201T000000!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fcb_client%3Dmaps_sv.tactile%26w%3D900%26h%3D600%26pitch%3D6.350131535504943%26panoid%3DMLw6N-4LJATrLh344-zoUA%26yaw%3D195.84306068163684!7i16384!8i8192?entry=ttu&g_ep=EgoyMDI1MDUyOC4wIKXMDSoASAFQAw%3D%3D

83/LPP/Fletcher Way: Probably the busiest light here, an arterial faces a residential area. I don't drive thru here so I can't say much about it, but I also couldn't find an example of the FYA being active on street view.
https://www.google.com/maps/@33.6721144,-112.2399435,3a,37.5y,229.09h,82.4t/data=!3m8!1e1!3m6!1sUd_qR0wnMAbldYI7cRyBYQ!2e0!5s20220601T000000!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fcb_client%3Dmaps_sv.tactile%26w%3D900%26h%3D600%26pitch%3D7.603508354766049%26panoid%3DUd_qR0wnMAbldYI7cRyBYQ%26yaw%3D229.09378938519944!7i16384!8i8192?entry=ttu&g_ep=EgoyMDI1MDUyOC4wIKXMDSoASAFQAw%3D%3D

Vistancia Blvd/Jomax: New construction. Also never been thru here so I can't speak for it, but the surrounding area is not yet developed. The left turn heads towards the freeway. This one might be weekday restricted, as the 2023 February street view shows a consistent red arrow/green circle pairing. This also appears to be one of the last california traffic poles before Peoria switched to the "monster" style poles.
https://www.google.com/maps/@33.732047,-112.3142041,3a,37.5y,134.13h,87.9t/data=!3m7!1e1!3m5!1svUOYhUfDf7puV2cjrg7sTg!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fcb_client%3Dmaps_sv.tactile%26w%3D900%26h%3D600%26pitch%3D2.104122032971631%26panoid%3DvUOYhUfDf7puV2cjrg7sTg%26yaw%3D134.1296266562819!7i16384!8i8192?entry=ttu&g_ep=EgoyMDI1MDUyOC4wIKXMDSoASAFQAw%3D%3D

Northern Parkway/Sarival Ave: Also never been thru here. Diamond interchange, similar to 303/LPP, where the parkway entrance has two left turning lanes across a single thru lane. This one utilizes the tallboi 5-section signal, rather than the FYA.
https://www.google.com/maps/@33.558566,-112.4097343,3a,75y,179.04h,86.12t/data=!3m8!1e1!3m6!1s1lelat_YY-sNu8YtU9GhVA!2e0!5s20210201T000000!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fcb_client%3Dmaps_sv.tactile%26w%3D900%26h%3D600%26pitch%3D3.881640597169266%26panoid%3D1lelat_YY-sNu8YtU9GhVA%26yaw%3D179.03628510528296!7i16384!8i8192?entry=ttug_ep=EgoyMDI1MDUyOC4wIKXMDSoASAFQAw%3D%3D

Honorable mentions:
There are a few intersections that utilize FYA signal heads but the FYA is permanently inactive: 75/peoria and 75/cactus are double lefts on all four sides (unnecessarily so IMO), but have FYA signal heads. 75/cactus malfunctioned once, January 4, 2021, and gave FYA when it shouldn't have. I have no video or photographic evidence of this sadly, nor were any news reports or blog posts made, but I still remember the feeling that something just isn't right when I first saw it.