Mike's Railroad Crossing Forum

mlgillson wrote: Couple other things. Most traffic signals that I've ever seen on a single pole, seven. Dual left turn lane, three thru lanes, dual right turn lane, a signal for each lane.

There is an intersection Overland Park with seven signal heads although only six are on the horizontal pole.

http://maps.google.com/maps?client=fire ... 91717&z=17

I caught this watching COPS tonight. Check out the odd shape of these cantilevers in Sacramento CA. There were several of these at various intersections:

http://maps.google.com/maps?f=q&source= ... 4050632911

cabman701 wrote:I caught this watching COPS tonight. Check out the odd shape of these cantilevers in Sacramento CA. There were several of these at various intersections:

http://maps.google.com/maps?f=q&source= ... 4050632911

There are quite a few signal like that in the Sacramento area. It just looks ugly. Though most new signals that are being put in have just the curved monotube without that dropped end.

Some 3M-style lights are installed in my area, usually in places where two intersections are very close in proximity to eachother. The 3M-style lights are installed at the second intersection so that the 1st intersection's lights are more visable so people will pay more attention to that intersection's lights instead of the 3M-style intersection's lights so that there's no confusion.

Also, another traffic light feature popular round here is strobe lights being added to the signals (usually on the red light).

The last time a new 3M signal was installed around Portland was in 2003 or so when they completed the Interstate MAX line. There are maybe six or seven along that stretch but it makes sense they wouldn't show up much later than that because they aren't in production anymore (as of 2005). Since then, whenever they need a programmable visibility signal, they use the McCain PV which is essentially a carbon copy of the 3M HVS with the exception of round lenses instead of square ones.

Josh wrote:Hey, has anyone ever seen something like this: (I wish I had a picture, but I'll just have to try to describe it) It's a combination turn signal arrow, with both green and yellow in the same lens section, except it used fiber optics to display the arrows. Plano, TX had a ton of these back in the 80's and early 90's when they used vertically-mounted signals. But they have all been removed and replaced in the last several years. I am guessing that these were somehow not compliant in that color-blind people would have a very hard time telling what arrow was lit since they were in the same lens. But they looked very cool, especially the way the arrow would shift slightly up and right to the next set of "dots" when it changed from the green arrow to the yellow arrow. Anyone else ever seen these?

Yes. LOTS of those around here. I've never had difficulty telling the green arrow from the yellow arrow though. You know what the cool thing is? They're able to be retrofitted w/ LEDs! Lots of them have been, and I think it's pretty cool. Here's a few locations:

http://maps.google.com/?ie=UTF8&ll=42.9 ... ,,0,1.0625

http://maps.google.com/?ie=UTF8&ll=42.8 ... 9999999964

http://maps.google.com/?ie=UTF8&ll=42.8 ... 4999999994

http://maps.google.com/?ie=UTF8&ll=42.8 ... 4999999996

http://maps.google.com/?ie=UTF8&ll=42.7 ... 4999999978

http://maps.google.com/?ie=UTF8&ll=42.8 ... 4999999996

If you look closely on some of the pics, you can see the shinyness of the LED lens. It seems to be popular because the LEDs clearly help distinguish between green and yellow, plus, it's probably cheaper than replacing the whole traffic signal.

Here's something I don't see much of here or in AR.A red arrow.There is no traffic light in Pine Bluff with a red arrow.

Those 'transforming' arrows are used by ODOT when they install a flashing protective/permissive left turn signal on a span wire. It has a red left arrow on top, a yellow left arrow in the middle, and then the transformer at the bottom. If cross traffic has the right of way, obviously all signals on that approach show red, the left turn signal stays showing red.

If a car is waiting to make a left, the light will change like a standard protected left, going from a red left arrow, to a green one. It will then use the middle yellow indication to return to red for about 5 seconds to allow oncoming traffic to start moving. Then the bottom indication will re-activate but using the amber element instead in a flashing sequence, telling you it's okay to make your turn but you must yield to oncoming traffic.

If no car is waiting to make a left, it simply holds the red left arrow for about 5 seconds to allow oncoming traffic to start moving and then goes into the flashing yellow left.

Bottom indication showing green/protected left movement

Bottom indication showing flashing yellow for permissive left.

And a traditional pole-mounted 4-section flashing left showing permissive left movement

I'll shoot a video of one of these in action when I get home.

The 3M Signal has it's own Wikipedia page now! I looked through it and it seems to be very accurate.

3M HVS Wiki Page