Traffic signal

[agentsteel53]

Texas is the only place I've noticed this. But I've seen traffic lights with what amounts to a 40-watt bulb mounted on the side that go on and off in tandem with the red lights.

What is the purpose of this? Are they supposed to enhance the visual of the red? Or are they for alerting cross traffic a green is forthcoming? Or is it a pedestrian deal?

they exist in either Florida or Alabama as well.  (can't remember which.)  Alex calls them "rat lights" and says their purpose is to let a police officer know when a light is red, so that he can catch violators without having a direct view of the red light itself.

[NE2]

Texas is the only place I've noticed this. But I've seen traffic lights with what amounts to a 40-watt bulb mounted on the side that go on and off in tandem with the red lights.

What is the purpose of this? Are they supposed to enhance the visual of the red? Or are they for alerting cross traffic a green is forthcoming? Or is it a pedestrian deal?

http://safety.fhwa.dot.gov/intersection/resources/techsum/fhwasa09005/

[Brandon]

Texas is the only place I've noticed this. But I've seen traffic lights with what amounts to a 40-watt bulb mounted on the side that go on and off in tandem with the red lights.

What is the purpose of this? Are they supposed to enhance the visual of the red? Or are they for alerting cross traffic a green is forthcoming? Or is it a pedestrian deal?

they exist in either Florida or Alabama as well.  (can't remember which.)  Alex calls them "rat lights" and says their purpose is to let a police officer know when a light is red, so that he can catch violators without having a direct view of the red light itself.

They're for idiots who claim to be cops, IMHO.  Any fool, IMHO, can figure out when the light is red for a particular direction at a signal without these lights.  Somehow, around here, they figure out which direction is red without any silly "rat lights".

[agentsteel53]

They're for idiots who claim to be cops, IMHO.  Any fool, IMHO, can figure out when the light is red for a particular direction at a signal without these lights.  Somehow, around here, they figure out which direction is red without any silly "rat lights".

generally speaking, I cannot look at an intersection and tell you exactly which lights are red.

specifically, I cannot tell you which light is green, and happens to have no traffic.

but, then again, signal phasings get really tricky around here.

[NE2]

Any fool, IMHO, can figure out when the light is red for a particular direction at a signal without these lights.

There's a definite legal difference between an educated guess and a near certainty.

[Brandon]

Any fool, IMHO, can figure out when the light is red for a particular direction at a signal without these lights.

There's a definite legal difference between an educated guess and a near certainty.

Um, at most intersections (4-way), if one street is green, the other street must obviously be red.  I'd say that's pretty damn certain.

[NE2]

Any fool, IMHO, can figure out when the light is red for a particular direction at a signal without these lights.

There's a definite legal difference between an educated guess and a near certainty.

Um, at most intersections (4-way), if one street is green, the other street must obviously be red.  I'd say that's pretty damn certain.

Unless the light's malfunctioning. The rat light is directly connected to the red and thus has much less (if any) reasonable doubt.

[Brandon]

Any fool, IMHO, can figure out when the light is red for a particular direction at a signal without these lights.

There's a definite legal difference between an educated guess and a near certainty.

Um, at most intersections (4-way), if one street is green, the other street must obviously be red.  I'd say that's pretty damn certain.

Unless the light's malfunctioning. The rat light is directly connected to the red and thus has much less (if any) reasonable doubt.

If the signal is malfunctioning, you've got bigger problems than the need for a so-called "rat light".

[agentsteel53]

Um, at most intersections (4-way), if one street is green, the other street must obviously be red.  I'd say that's pretty damn certain.

what if the police officer is sitting at a branch which is red?  then how does he know which of the other branches is green?  assume a non-intuitive sequence between the various turning and straight phases.

[Kacie Jane]

Any fool, IMHO, can figure out when the light is red for a particular direction at a signal without these lights.

There's a definite legal difference between an educated guess and a near certainty.

Um, at most intersections (4-way), if one street is green, the other street must obviously be red.  I'd say that's pretty damn certain.

Keep in mind that most red light runners don't blow through a light that's been red for a while.  They run it just as it's turning red, possibly before cross traffic gets their green.  So in order to ticket them, the cop needs to be able to tell exactly when the light turned red.

[kphoger]

Which begs the question:  If cross traffic hasn't even received a green light yet, then why ticket the offender at all?

[agentsteel53]

Which begs the question:  If cross traffic hasn't even received a green light yet, then why ticket the offender at all?

if it were made legal to enter an intersection when no one has green, then people would enter intersections in such situations, figuring they could get away with it.  and when they couldn't (because the opposing traffic had just, indeed, received green), the result is not a ticket, but a collision.

it's best to keep the "can I get away with it?" decision point several seconds before the danger point, which is how it is now.

[Scott5114]

Additionally, it can get kind of difficult to figure out a timing sequence when you have lots of things like left and right turn arrows, pedestrian phases, signal actuation, etc. going on.

[Michael]

I just stumbled on this modern 12-8-8 signal for the Fairport Lift Bridge over the Erie Canal in Fairport, NY:

Credit: HistoricBridges.org

I didn't think 12-8-8's were made anymore, plus this one looks like it had LEDs in it.  Click the image to enlarge it, and look at the green ball on the right side.  It looks like there's some LEDs that aren't working.

As for the bridge itself, it's really neat.  It crosses the canal at an angle, and the road deck is on an incline.  Here's the HistoricBridges.org page for the bridge.

[NYhwyfan]

I just stumbled on this modern 12-8-8 signal for the Fairport Lift Bridge over the Erie Canal in Fairport, NY:

Credit: HistoricBridges.org

I didn't think 12-8-8's were made anymore, plus this one looks like it had LEDs in it.  Click the image to enlarge it, and look at the green ball on the right side.  It looks like there's some LEDs that aren't working.

As for the bridge itself, it's really neat.  It crosses the canal at an angle, and the road deck is on an incline.  Here's the HistoricBridges.org page for the bridge.

A few of the lift bridge signals for the Erie Canal between Lockport and Albion have 12-8-8 signals, some older. Most have seem to been replaced with newer 12-12-12. 

Here's a new 12-8-8 in Albion, NY http://maps.google.com/?ll=43.24861,-78.193688&spn=0.004165,0.009645&t=h&z=17&layer=c&cbll=43.248694,-78.19368&panoid=3qosjcTSABawsteFWZPMGQ&cbp=12,355.87,,0,-1.6

[jeffandnicole]

Which begs the question:  If cross traffic hasn't even received a green light yet, then why ticket the offender at all?

So you're OK with motorists crossing into an intersection just after a light turns red, along with motorists entering an intersection just before the light turns green.  Interesting.  Experiment with that for a while and let us know how it goes.

[SignBridge]

Yeah, what jeffandnicole said. And yes, let us know how it works out for you..........

[kphoger]

Other than the obviously dangerous (and not suggested by me) starting before your light turns green, what would be the conflicting traffic movement?  Lots of people don't stop before turning right when their light has just turned red, before cross traffic gets their green, and it "works out" perfectly well.  Unless you mean getting a ticket, which is precisely what brought it up in the first place.  I do it with some frequency, and it "works out" just great, thank you for asking. 

[PHLBOS]

I didn't think 12-8-8's were made anymore

While I was in Salem, OR a couple years ago; I saw some newer 12-8-8s around.

[SignBridge]

I never understood the use of the 12-8-8 configuration. If the location needed a 12-inch signal, then just use 12-inch for the whole signal head. Why go half-way?

[dfnva]

 I didn't think 12-8-8's were made anymore, plus this one looks like it had LEDs in it.  Click the image to enlarge it, and look at the green ball on the right side.  It looks like there's some LEDs that aren't working.[/quote]

VDOT put up new 12-8-8's maybe 7 years ago at two interesections in Woodbridge, VA.... the intersections of US-1 with Featherstone Rd and with Woodside Dr. Oddly, the ones at Woodside Dr were replaced with new mast arms a couple years later. The ones at Featherstone remain. The 12-8-8's face traffic on Featherstone Rd. Ironically, the signals there prior to the replacement (on the same span wire) were full size 12-inch signal (old Peek / Crouse-Hinds signals from the 70s/80s).

http://maps.google.com/maps?q=Woodbridge,+VA&hl=en&ll=38.636886,-77.26927&spn=0.011481,0.022724&sll=38.744659,-77.487094&sspn=0.091712,0.181789&oq=woodb&hnear=Woodbridge,+Prince+William,+Virginia&t=m&z=16&layer=c&cbll=38.636772,-77.26937&panoid=Jzmm8p1Y8BbHIaYTq55Jqw&cbp=12,13.26,,0,6.37

[myosh_tino]

While I haven't seen any new 12-8-8 signals installed in the S.F. Bay Area lately, some cities are retrofitting their older 12-8-8 signals with LED lights.  All new installations I've seen are either 12-12-12 or 8-8-8 signal heads.  FWIW, California used to use 8-8-12 for left-turn signals but that practice was discontinued when we switched to an all-arrow signals.

[PHLBOS]

I never understood the use of the 12-8-8 configuration. If the location needed a 12-inch signal, then just use 12-inch for the whole signal head. Why go half-way?

Guess on my part, but the 12-8-8 setup likely predates most if not all-12 setups. 

Back then, the reasoning for red signal head having the larger head was due to it was considered more important for motorists to see a red signal from a greater distance than a green or yellow signal.

It's worth noting that some communities went w/a 12-12-8 setup.  Peabody, MA being one of them and still has a few signals that feature this setup to this day.  The rationale for the larger yellow (along with the red) was likely for more distant viewing.

[Ian]

From what I've seen, 12-8-8 signals are still being installed in Ontario.

[NYhwyfan]

http://maps.google.com/?ll=43.0125,-78.879615&spn=0.004181,0.009645&t=h&z=17&layer=c&cbll=43.012404,-78.879637&panoid=AuYWs39Jl5DCPENtJ8m-dg&cbp=12,2.67,,0,2.15

Fairly new (w/in last 5 years) using 12-8-8 for the primary signals and 8-8-8 for secondaries
Tonawanda, NY

http://maps.google.com/?ll=43.021914,-78.877974&spn=0.003961,0.009645&t=h&z=17&layer=c&cbll=43.02201,-78.877937&panoid=Q_Ja6l1VyzM7L7JJV_D0nA&cbp=12,19.44,,0,-30.43

Older 12-8-8 after crossing over the Erie Canal in North Tonawanda, NY

http://maps.google.com/?ll=43.032455,-78.876461&spn=0.00396,0.009645&t=h&z=17&layer=c&cbll=43.032597,-78.876462&panoid=A9EgOPUK2wcCHAQC1KO2-w&cbp=12,173.53,,0,-5.21 North Tonawanda, NY