Beacons and traffic signals being used together simultaneously

[index]

https://www.google.com/maps/@47.7210898,-122.2940735,3a,70.2y,257.55h,88.73t/data=!3m6!1e1!3m4!1sbY_SbYop8vnKIiE7ATeU3A!2e0!7i16384!8i8192
This intersection in Seattle features that. Another interesting thing is that it uses programmable visibility beacons, which, to my understanding, are pretty rare. Beacons being PV, not PV itself. Although 3Ms are thinning out ever since they were discontinued. If only McCain used square visors too, the circular visors and the housing is a lame aesthetic.


These are used alongside the regular signals, operating simultaneously, traffic from the direction of the beacons doesn't have to wait for a light (the newest street view shows all the signals out), they can stop once and then go.

[mrsman]

https://www.google.com/maps/@47.7210898,-122.2940735,3a,70.2y,257.55h,88.73t/data=!3m6!1e1!3m4!1sbY_SbYop8vnKIiE7ATeU3A!2e0!7i16384!8i8192
This intersection in Seattle features that. Another interesting thing is that it uses programmable visibility beacons, which, to my understanding, are pretty rare. These are used alongside the regular signals, operating simultaneously, traffic from the direction of the beacons doesn't have to wait for a light (the newest street view shows all the signals out), they can stop once and then go.

What you have there is a situation that is basically  a driveway controlled by a stop-sign equivalent at a T-intersection.  Essentially, regardless of whether cross traffic or opposing traffic has the right of way, traffic out of the alley must stop, yield to whomever has the right of way and only turn right.

L.A. has similar infrastructure, but signals the driveway side differently.  Years ago, they used a 2 aspect solid red and flashing red signal.  Solid red - with normal meaning allows for RTOR after stop - during cross traffic's phase.  Flashing red - during opposing traffic's phase - is treated as a stop sign, meaning that even straight through traffic would have to yield to opposing lefts.  More recent incarnations of the singal have added a yellow light to come on when opposing traffic has yellow light to warn of the change from opposing traffic's right of way to cross traffic right of way.

In my experience, at most of the lights, drivers did not really observe the flashing red properly (by yielding to opposing traffic) so many were changed to traditional RYG signals.  I am not aware of any that forced a right turn, like the Seattle example, but if it did, it  would probably be respected more.

This intersection at Sunset/Poinsettia used to have the red-flashing red signal for those who exited from the Ralph's supermarket parking lot, but now the signal is tradition RYG.  My guess is that there is enough traffic coming from this lot, that a regular signal is warranted.:

https://www.google.com/maps/@34.0979453,-118.3484703,3a,75y,59.3h,88.81t/data=!3m6!1e1!3m4!1s3oHENd0sr5zoQNPSIkCpAA!2e0!7i16384!8i8192

This intersection at Pico/Livonia has the newer Red-Flashing Red-Yellow signal for traffic exiting Wells Fargo parking lot.  Traffic from the bank sees flashing red, while traffic coming from Livonia sees green.  Traffic from the bank is expected to "watch opposing traffic" and from my understanding of the rules is supposed to yield to opposing lefts, but the sign isn't clear on that point.

https://www.google.com/maps/@34.0551781,-118.3863096,3a,75y,291.64h,91.46t/data=!3m6!1e1!3m4!1sgDfPl-XyfEivPNanRbJ5Mg!2e0!7i16384!8i8192

[fwydriver405]

I know of two intersections that are like that: One in Dover NH, and the other in St Helena CA. There may be a few more CA examples, especially around the Silicon Valley...

I'm not sure when, but in both of those examples, the flashing red will go solid at some point in the cycle.

[DrSmith]

One example on Rt 9 in Howell, NJ. It seems like the flasher isn't active and is potentially for the fire station on the side street and likely the reason for the break in the median. Potentially only flashes yellow and is a variation on a fire signal?
https://goo.gl/maps/kcAKT8hZXuBTf8Lc6

Route 2 in Fitchburg, Mass has a split between between sides of the road. There is no crossing Route 2. Eastbound (and south side of Mt Elam Rd) is a signal and Westbound (and north side of Mt Elam Rd) is a flasher. Also, a couple of 3M's in there too
https://goo.gl/maps/fRNp6Z4yJjUz9aHX6 (Eastbound)
https://goo.gl/maps/AmE7MsjQSAFD4hMJ7 (Westbound)

[echo]

This one located at the intersection of Prospect and Pond St in Pawtucket https://www.google.com/maps/@41.8710335,-71.3781052,3a,37.5y,257.88h,90.77t/data=!3m6!1e1!3m4!1sQGPuSn8JiFybKJWrRprbNw!2e0!7i16384!8i8192. Its plausible the beacon might serve no more practical purpose as a) McCoy Stadium (accessible via pond st) no longer hosts games and b) Memorial Hospital (on the South East corner of the intersection) effectively closed a couple years back   

[MarkF]

https://www.google.com/maps/@47.7210898,-122.2940735,3a,70.2y,257.55h,88.73t/data=!3m6!1e1!3m4!1sbY_SbYop8vnKIiE7ATeU3A!2e0!7i16384!8i8192
This intersection in Seattle features that. Another interesting thing is that it uses programmable visibility beacons, which, to my understanding, are pretty rare. These are used alongside the regular signals, operating simultaneously, traffic from the direction of the beacons doesn't have to wait for a light (the newest street view shows all the signals out), they can stop once and then go.

What you have there is a situation that is basically  a driveway controlled by a stop-sign equivalent at a T-intersection.  Essentially, regardless of whether cross traffic or opposing traffic has the right of way, traffic out of the alley must stop, yield to whomever has the right of way and only turn right.

L.A. has similar infrastructure, but signals the driveway side differently.  Years ago, they used a 2 aspect solid red and flashing red signal.  Solid red - with normal meaning allows for RTOR after stop - during cross traffic's phase.  Flashing red - during opposing traffic's phase - is treated as a stop sign, meaning that even straight through traffic would have to yield to opposing lefts.  More recent incarnations of the singal have added a yellow light to come on when opposing traffic has yellow light to warn of the change from opposing traffic's right of way to cross traffic right of way.

In my experience, at most of the lights, drivers did not really observe the flashing red properly (by yielding to opposing traffic) so many were changed to traditional RYG signals.  I am not aware of any that forced a right turn, like the Seattle example, but if it did, it  would probably be respected more.

This intersection at Sunset/Poinsettia used to have the red-flashing red signal for those who exited from the Ralph's supermarket parking lot, but now the signal is tradition RYG.  My guess is that there is enough traffic coming from this lot, that a regular signal is warranted.:

https://www.google.com/maps/@34.0979453,-118.3484703,3a,75y,59.3h,88.81t/data=!3m6!1e1!3m4!1s3oHENd0sr5zoQNPSIkCpAA!2e0!7i16384!8i8192

This intersection at Pico/Livonia has the newer Red-Flashing Red-Yellow signal for traffic exiting Wells Fargo parking lot.  Traffic from the bank sees flashing red, while traffic coming from Livonia sees green.  Traffic from the bank is expected to "watch opposing traffic" and from my understanding of the rules is supposed to yield to opposing lefts, but the sign isn't clear on that point.

https://www.google.com/maps/@34.0551781,-118.3863096,3a,75y,291.64h,91.46t/data=!3m6!1e1!3m4!1sgDfPl-XyfEivPNanRbJ5Mg!2e0!7i16384!8i8192

Here's one in L.A.'s Chinatown at Broadway and Bernard, coming out of a parking garage (next to my favorite Chinese restaurant in L.A.):
https://goo.gl/maps/MZDCTVAoEZggMZ7x9
Even though the light has three elements, I've only seen it with a solid red (when green on Broadway) or flashing red when red on Broadway.  I'm not sure what the light shows on the Bernard Street side, but I think it is a standard signal.

[rellis97]

https://www.google.com/maps/@42.4562402,-83.3559685,3a,59.9y,304.54h,95.12t/data=!3m6!1e1!3m4!1sUO51gcQ59MlV9Z3SNS_rXA!2e0!7i16384!8i8192
Here's an example in Farmington, MI at the corner of Grand River Avenue and Orchard Lake Rd.

[roadman65]

One example on Rt 9 in Howell, NJ. It seems like the flasher isn't active and is potentially for the fire station on the side street and likely the reason for the break in the median. Potentially only flashes yellow and is a variation on a fire signal?
https://goo.gl/maps/kcAKT8hZXuBTf8Lc6

Route 2 in Fitchburg, Mass has a split between between sides of the road. There is no crossing Route 2. Eastbound (and south side of Mt Elam Rd) is a signal and Westbound (and north side of Mt Elam Rd) is a flasher. Also, a couple of 3M's in there too
https://goo.gl/maps/fRNp6Z4yJjUz9aHX6 (Eastbound)
https://goo.gl/maps/AmE7MsjQSAFD4hMJ7 (Westbound)

It's a crosswalk signal that doubles as a fire signal.

[steviep24]

The signals at NY 96 and High St. in Victor, NY has beacons serving driveways.

https://www.google.com/maps/@42.984438,-77.4136661,3a,75y,318.07h,95.39t/data=!3m6!1e1!3m4!1spHUgNr85AJ9Iv6qh4E9Esw!2e0!7i16384!8i8192?hl=en&authuser=0

[mrsman]

This one located at the intersection of Prospect and Pond St in Pawtucket https://www.google.com/maps/@41.8710335,-71.3781052,3a,37.5y,257.88h,90.77t/data=!3m6!1e1!3m4!1sQGPuSn8JiFybKJWrRprbNw!2e0!7i16384!8i8192. Its plausible the beacon might serve no more practical purpose as a) McCoy Stadium (accessible via pond st) no longer hosts games and b) Memorial Hospital (on the South East corner of the intersection) effectively closed a couple years back   

This seems like the ideal layout for a signal/beacon intersection.  Because of the forced channelized right turn that faces a stop sign, it is clear that traffic coming from the smaller street must stop and yield, regardless of whether cross traffic or opposing traffic has right of way.  The channelization helps, because it puts the traffic from the smaller street just ahead of the regular intersection.

[roadman65]

US 9 in Glens Falls NY had a signal that when green on the US Route it flashed red on the side street. That was basically a signal on demand and would only turn red on Route 9 if traffic was in queue for a maximum time waiting to cross. 

The last time there it was changed to a normal operating signal.  This was in 2012, but this was early to mid seventies that it worked part time as I was a child then with my parents.

[stevashe]

Here's one used at a more normal intersection for an actual street approach in San Francisco: https://goo.gl/maps/2hzNLE16sk7vU23Y9

The reason it has a beacon is due to the configuration of the one-way streets in the vicinity and this approach being much more minor than the others at this intersection.

[mrsman]

Here's one used at a more normal intersection for an actual street approach in San Francisco: https://goo.gl/maps/2hzNLE16sk7vU23Y9

The reason it has a beacon is due to the configuration of the one-way streets in the vicinity and this approach being much more minor than the others at this intersection.

That is a weird one.  Do you know if the red is always blinking, or does it go solid red at times?  One would think that if there was always flashing a stop sign would be in order.  Then again, it may also be helpful to have a distinction between yielding to cross traffic vs. yielding to opposing traffic.  I am aware of some intersections in L.A., where the minor approaches faces a signal with no green light: solid red when cross traffic has right of way and flashing red when opposing traffic has right of way.  E.g. Pico/Livonia, which I mentioned upthread.


Another weird intersection in SF is where the cable car lines cross at California/Powell.  The beacons are on all corners, so nominally a 4-way stop without the stop signs, but then there is that weird signal controlling the cable car movements.  And then warning signs that the cable cars won't stop!  Probably a scary corner in practice.   

https://www.google.com/maps/@37.7920073,-122.4091173,3a,75y,158.41h,85.21t/data=!3m6!1e1!3m4!1s4gu4Wy7l1mXCUVmisWvjCQ!2e0!7i16384!8i8192

[JoePCool14]

Here's one used at a more normal intersection for an actual street approach in San Francisco: https://goo.gl/maps/2hzNLE16sk7vU23Y9

The reason it has a beacon is due to the configuration of the one-way streets in the vicinity and this approach being much more minor than the others at this intersection.

That is a weird one.  Do you know if the red is always blinking, or does it go solid red at times?  One would think that if there was always flashing a stop sign would be in order.  Then again, it may also be helpful to have a distinction between yielding to cross traffic vs. yielding to opposing traffic.  I am aware of some intersections in L.A., where the minor approaches faces a signal with no green light: solid red when cross traffic has right of way and flashing red when opposing traffic has right of way.  E.g. Pico/Livonia, which I mentioned upthread.


Another weird intersection in SF is where the cable car lines cross at California/Powell.  The beacons are on all corners, so nominally a 4-way stop without the stop signs, but then there is that weird signal controlling the cable car movements.  And then warning signs that the cable cars won't stop!  Probably a scary corner in practice.   

https://www.google.com/maps/@37.7920073,-122.4091173,3a,75y,158.41h,85.21t/data=!3m6!1e1!3m4!1s4gu4Wy7l1mXCUVmisWvjCQ!2e0!7i16384!8i8192

Yikes, that one you just linked should probably be fully signalized, unless it's very infrequent when it comes to cable cars passing through. It feels like there's a lot going on there, yet at the same time it doesn't really convey much. Confusing.

[mrsman]

Here's one used at a more normal intersection for an actual street approach in San Francisco: https://goo.gl/maps/2hzNLE16sk7vU23Y9

The reason it has a beacon is due to the configuration of the one-way streets in the vicinity and this approach being much more minor than the others at this intersection.

That is a weird one.  Do you know if the red is always blinking, or does it go solid red at times?  One would think that if there was always flashing a stop sign would be in order.  Then again, it may also be helpful to have a distinction between yielding to cross traffic vs. yielding to opposing traffic.  I am aware of some intersections in L.A., where the minor approaches faces a signal with no green light: solid red when cross traffic has right of way and flashing red when opposing traffic has right of way.  E.g. Pico/Livonia, which I mentioned upthread.


Another weird intersection in SF is where the cable car lines cross at California/Powell.  The beacons are on all corners, so nominally a 4-way stop without the stop signs, but then there is that weird signal controlling the cable car movements.  And then warning signs that the cable cars won't stop!  Probably a scary corner in practice.   

https://www.google.com/maps/@37.7920073,-122.4091173,3a,75y,158.41h,85.21t/data=!3m6!1e1!3m4!1s4gu4Wy7l1mXCUVmisWvjCQ!2e0!7i16384!8i8192

Yikes, that one you just linked should probably be fully signalized, unless it's very infrequent when it comes to cable cars passing through. It feels like there's a lot going on there, yet at the same time it doesn't really convey much. Confusing.

I agree.  I believe that due to the crest of the hills, and the fact that the two cable car lines cross there, it is difficult for the cable cars to stop there.

Here is a little info on the cable car ops:

https://www.streetcar.org/wheels-motion/cable-cars-work/

I still think that it should be possible to have regular signalization for the other traffic, and then an all-red phase to give absolute priority to the cable car when it passes through.  THe all-way stop in an intersection with lots of peds, cable cars, and two busy streets (one with two lanes in each direction) is a little crazy.