I just drove this road the other day, and noticed an excellent solution to the problem of a traffic signal being around a curve: place it on the opposing mastarm, at the front of the intersection.
http://goo.gl/maps/p265x
as you can see, the mastarm has traffic signals for both directions. this helps because the primary signals for southbound at that intersection are around a curve.
elsewhere, here is an example of an intersection that could use a traffic signal on the opposing mastarm.
http://goo.gl/maps/z9yW6
here, the google car was viewing this approach backwards, and the added parallax shows the red light behind the tree - westbound traffic in the correct lane would not see it until later, almost dangerously so. this is an intersection that could benefit from another signal being placed on the opposing
mastarm.
I've often thought that was needed here (http://goo.gl/maps/0OC0s), at Hillside and 9th in Wichita. Southbound traffic comes over a small hill on a gradual curve, and the only stoplights are pole-mounted. There's a perfect spot for one on the opposite mastarm, which would be visible before any of the others.
Maybe I'm used to the Jersey way of doing things, but more often than not there's at least one signal over the opposing lanes. In this case ( http://goo.gl/maps/qwCXI ) there's a signal on the far ground-mounted pole for the mastarm due to a curve in the road (exiting out of the street view reveals the curve in the road; the hazy street cam doesn't show the curve or the light very well from a distance)
That is frequently done in Georgia in those situations.
Pennsylvania does it a lot...
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Ffarm6.staticflickr.com%2F5051%2F5501288966_fc28a20764_z.jpg&hash=75d9a6b63e42f253708f4991dd750bf50052a03b)
And in more extreme cases...
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Ffarm6.staticflickr.com%2F5052%2F5540813937_d40a459147_z.jpg&hash=e1427ea8aaad816d4a5332c7bd1be4ae71d3fbaa)
Quote from: agentsteel53 on May 28, 2013, 02:27:11 PM
I just drove this road the other day, and noticed an excellent solution to the problem of a traffic signal being around a curve: place it on the opposing mastarm, at the front of the intersection.
http://goo.gl/maps/p265x
as you can see, the mastarm has traffic signals for both directions. this helps because the primary signals for southbound at that intersection are around a curve.
This kind of set-up is common throughout various locations of New Jersey, not to mention the suburbs of New York City.
Though I agree it is a good alternative, a motorist, at first, may confuse that individual traffic signal head as a permissive signal, since it appears to face the left turn lane. Though I am sure that he or she would soon see those protected left turn traffic signals that control the lane. If it were up to me, I would adjust the head, so that it would face the thru lanes. Just to prevent confusion.
Virginia does this practice in some situations, but not others.
Here is an interesting situation, both a supplemental protected left and through signal next to each other. Not necessarily the best set up, but better than no supplemental signals at this curve as it was before 2012.
http://goo.gl/maps/7EVN7 (SR-641/Old Bridge Rd at SR-906/Occoquan Rd in Lake Ridge, VA)
I like the practice of supplemental signals (one the left and right far corners; and, in IL, on the close right corner) as is done in many Midwestern and Southwestern states, which mitigates this issue to an extent.
Quote from: dfnva on May 28, 2013, 04:44:45 PM
Virginia does this practice in some situations, but not others.
Here is an interesting situation, both a supplemental protected left and through signal next to each other. Not necessarily the best set up, but better than no supplemental signals at this curve as it was before 2012.
http://goo.gl/maps/7EVN7 (SR-641/Old Bridge Rd at SR-906/Occoquan Rd in Lake Ridge, VA)
I like the practice of supplemental signals (one the left and right far corners; and, in IL, on the close right corner) as is done in many Midwestern and Southwestern states, which mitigates this issue to an extent.
I can think of a place where Virginia's done that using
span wire: http://goo.gl/maps/VC4IC (Tysons Boulevard at Galleria Drive near Tysons II–the Google car only has an image from the other side of the road, but you can see the light well enough.) I remember the first time I encountered that left-turn light because I didn't even notice it up there–I was watching the other signals and only realized there was a left-turn light when Ms1995hoo said the light was green.
I've never known why they set it up that way, given that it isn't on a curve.
I never remembered seeing this when growing up in Georgia, but when I moved to Maryland I found that this was a common practice, and it struck me as brilliant. I now see it occasionally in Georgia, but not very often.
Quote from: kphoger on May 28, 2013, 02:50:28 PM
I've often thought that was needed here (http://goo.gl/maps/0OC0s), at Hillside and 9th in Wichita. Southbound traffic comes over a small hill on a gradual curve, and the only stoplights are pole-mounted. There's a perfect spot for one on the opposite mastarm, which would be visible before any of the others.
Agreed. Always hated that light. We have one that kind of fits this category - 13th and North River Blvd. in Riverside... http://goo.gl/maps/osVuI
ICTRds
Quote from: WichitaRoads on May 28, 2013, 05:41:16 PM
Quote from: kphoger on May 28, 2013, 02:50:28 PM
I've often thought that was needed here (http://goo.gl/maps/0OC0s), at Hillside and 9th in Wichita. Southbound traffic comes over a small hill on a gradual curve, and the only stoplights are pole-mounted. There's a perfect spot for one on the opposite mastarm, which would be visible before any of the others.
Agreed. Always hated that light. We have one that kind of fits this category - 13th and North River Blvd. in Riverside... http://goo.gl/maps/osVuI
ICTRds
Ah, yes, and just a few blocks from our friends' house. Thanks for the example.
The city of Hampton, VA did that a few years back when reconstructing the intersection of Fox Hill Rd (VA 169) and Woodland Rd:
http://goo.gl/maps/0SI36
Quote from: 1995hoo on May 28, 2013, 05:07:27 PM
Quote from: dfnva on May 28, 2013, 04:44:45 PM
Virginia does this practice in some situations, but not others.
Here is an interesting situation, both a supplemental protected left and through signal next to each other. Not necessarily the best set up, but better than no supplemental signals at this curve as it was before 2012.
http://goo.gl/maps/7EVN7 (SR-641/Old Bridge Rd at SR-906/Occoquan Rd in Lake Ridge, VA)
I like the practice of supplemental signals (one the left and right far corners; and, in IL, on the close right corner) as is done in many Midwestern and Southwestern states, which mitigates this issue to an extent.
I can think of a place where Virginia's done that using span wire: http://goo.gl/maps/VC4IC (Tysons Boulevard at Galleria Drive near Tysons II–the Google car only has an image from the other side of the road, but you can see the light well enough.) I remember the first time I encountered that left-turn light because I didn't even notice it up there–I was watching the other signals and only realized there was a left-turn light when Ms1995hoo said the light was green.
I've never known why they set it up that way, given that it isn't on a curve.
I know I'm getting off topic, but that's the problem I see with the set up with some newer VDOT signal installations - protected left turn signal exclusively on the close side of the intersection and through signals on the far side. I don't like it, a redundant far side protected left turn signal (on a mast arm or pedestal) should be used as well.
Examples (which include, but are not limited to):
http://goo.gl/maps/06f1L -- VA-253/Port Republic Rd and SR-726/Stone Spring Rd, Harrisonburg (Rockingham County)
http://goo.gl/maps/TkGHo -- SR-650/Gallows Rd and I-495, Merrifield
http://goo.gl/maps/ot1Z3 --- SR-620/Braddock Rd and I-495, Springfield
At one time, such a situation existed here http://goo.gl/maps/zq8D1 (Old Lee Hwy and Layton Hall Dr, Fairfax) until about 1990. A protected left signal was on the close mast arm, a unique situation at the time. It was replaced by a doghouse signal installed on the far side mast arm (like the Google Streetview, though, these are second generation signals/mast arms).
-Dan
Washington does this all the time, but it's more common to be placed on the parent mast, rather than the mast arm.
Signal on mast-arm:
http://goo.gl/maps/H5tFU
Signal on main mast:
http://goo.gl/maps/43oec
http://goo.gl/maps/vfJ3C
Both!:
http://goo.gl/maps/OfSR4
I've seen a few of these in Illinois, although not always mounted on the mastarms.
Pekin, IL, with flashing yellow arrows (http://maps.google.com/maps?hl=en&ll=40.555678,-89.606037&spn=0.008722,0.021136&t=m&z=16&layer=c&cbll=40.555942,-89.610888&panoid=IGFCYxhBC7tHy8f1xU445g&cbp=12,138.46,,2,-2.16)
Quote from: Brandon on May 29, 2013, 12:58:47 PM
I've seen a few of these in Illinois, although not always mounted on the mastarms.
Pekin, IL, with flashing yellow arrows (http://maps.google.com/maps?hl=en&ll=40.555678,-89.606037&spn=0.008722,0.021136&t=m&z=16&layer=c&cbll=40.555942,-89.610888&panoid=IGFCYxhBC7tHy8f1xU445g&cbp=12,138.46,,2,-2.16)
It seems there used alot when they redo major intersections. Great example would be US 6 (159th street) and US 45 (LaGrange Road), where is used to be only one mastarm. Now they have a double oncoming there and building another one up the road at 143rd and 141st
Kissimmee, FL and Orlando, FL are starting to adopt this practice.
New Jersey always had done this and PA is starting to do it in certain places.
What is needed is flashing signal ahead warnings before curves in many places. Sometimes even a left side head is not even visible until you are half way or more around the curve. Considering that most people nowadays do not drive safely and road rage is a norm a lot of the times, it would be a safe practice to impliment.
Quote from: roadman65 on May 29, 2013, 02:43:28 PM
Kissimmee, FL and Orlando, FL are starting to adopt this practice.
New Jersey always had done this and PA is starting to do it in certain places.
What is needed is flashing signal ahead warnings before curves in many places. Sometimes even a left side head is not even visible until you are half way or more around the curve. Considering that most people nowadays do not drive safely and road rage is a norm a lot of the times, it would be a safe practice to impliment.
I think what I would like more than just "signal ahead" is one that does "red light ahead when flashing." That way if the light is around a blind curve you know to expect stopped traffic. A mere "signal head" doesn't tell you whether the light's red or green.
the worst is that some states have the flashing yellow lights at the sign mean "signal about to turn yellow - prepare to stop", while others have it mean "yep, that's a traffic signal all right".
You could have Prepare to Stop warning signs.
California:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fwww.fhwa.dot.gov%2Fpublications%2Fresearch%2Foperations%2Fits%2F06108%2Fimages%2Ffig4_7.jpg&hash=517aff638f2860fd40676c31e4ace0aa7a1497f9)
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Ffarm4.static.flickr.com%2F3405%2F3439589435_5bbb975e40.jpg&hash=7a02a746c578d4aaa04864b2f287a5ac5bee10ba)
Alaska:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2F2.bp.blogspot.com%2F_cqx2M3DUACA%2FTOgqo8zQ-SI%2FAAAAAAAABDk%2F8SiW7JsAjbs%2Fs1600%2FDSCN3358.JPG&hash=ab957fffdf89d72772a92df15eb2b6a8454d267b)
British Columbia:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fupload.wikimedia.org%2Fwikipedia%2Fcommons%2F2%2F20%2F%2522Prepare_To_Stop_When_Amber_Flashing%2522_Sign.JPG&hash=06fecd0682434ee431a7e9693b9d47a76bf0d60a)
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fahhsome.files.wordpress.com%2F2011%2F07%2Fprepare-to-stop.png&hash=9f595a837a98280e743148f57fef1985aa948327)
Australia:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Ffarm3.staticflickr.com%2F2453%2F3878602310_4f2600831e.jpg&hash=2bc913cd608ab40f69559a68a1d5bc5293af91a2)
I personally am fond of Maryland's signs:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Ffarm4.static.flickr.com%2F3150%2F2504292968_b7ac0d75c2.jpg&hash=f71769d5789a2c7880fd566183815b857fccd8d2)
A typical design in NJ, which 'RED' would flash in the box (alternating with the always visible 'Signal Ahead') when the light is about to turn red, or is red.
http://goo.gl/maps/JEiB7
I never cared for this one (the image is poor, I know) on Rt. 4/7 in the Newport, DE area. http://goo.gl/maps/59SgW . The lights would flash only when the actual traffic light turned yellow (and then red) rather than in advance of the yellow, so quite frequently drivers will pass under the unlit sign, only to find the light turning red as they rounded the curve.
Quote from: deathtopumpkins on May 30, 2013, 01:39:02 AM
I personally am fond of Maryland's signs:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Ffarm4.static.flickr.com%2F3150%2F2504292968_b7ac0d75c2.jpg&hash=f71769d5789a2c7880fd566183815b857fccd8d2)
That, but usually on a mast arm, is exactly what PennDOT does.
Most of the advance warning signs like that I've seen are due to the high speed of traffic, not due to the curvature of the road.
At any rate, with or without advance warning sign, the point remains that a stoplight is often more visible to the approach when it's attached to the opposite mastarm.
I've seen a signal mounted on the vertical support of traffic signal on the opposite side of the street here, but not on the horizontal mast. We has yellow diamonds signs that read prepare to stop when flashing at "blind spots" for signals.
Mark
Quote from: Roadsguy on May 30, 2013, 10:54:25 AM
Quote from: deathtopumpkins on May 30, 2013, 01:39:02 AM
I personally am fond of Maryland's signs:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Ffarm4.static.flickr.com%2F3150%2F2504292968_b7ac0d75c2.jpg&hash=f71769d5789a2c7880fd566183815b857fccd8d2)
That, but usually on a mast arm, is exactly what PennDOT does.
Heck, even in Maryland, I think that picture is the first time I've seen a "Signal Ahead" with a "RED" option mounted on the ground anywhere.
Me too. I can only recall them being mounted overhead. That was just the best-quality photo I could find Googling.
Quote from: deathtopumpkins on May 30, 2013, 01:39:02 AM
I personally am fond of Maryland's signs:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Ffarm4.static.flickr.com%2F3150%2F2504292968_b7ac0d75c2.jpg&hash=f71769d5789a2c7880fd566183815b857fccd8d2)
There were some of those around Springfield, MO. All the other MoDOT districts seem to use the simpler 'be prepared to stop when flashing' with a yellow beacon over the sign.
Quote from: deathtopumpkins on May 30, 2013, 08:32:13 PM
Me too. I can only recall them being mounted overhead. That was just the best-quality photo I could find Googling.
I'm more apt to find them ground mounted...or mounted on a light pole. The overhead signs seem to be few and far inbetween when this sign is used.
Quote from: deathtopumpkins on May 30, 2013, 08:32:13 PM
Me too. I can only recall them being mounted overhead. That was just the best-quality photo I could find Googling.
I know of several in Massachusetts. Two on MA 9 westbound in Framingham...
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Ffarm8.staticflickr.com%2F7180%2F6913588931_68249734c4_z.jpg&hash=f0a34c1a4ac10062e48b072f49023ef926094d23)
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Ffarm8.staticflickr.com%2F7182%2F6913594173_42ec254d77_z.jpg&hash=1b84f8b8188dd0ad2042632e28c70ad5fddda54c)
And another on the Speen Street ramp from MA 9 eastbound in Natick...
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Ffarm9.staticflickr.com%2F8482%2F8245402511_f2fd3077f1_z.jpg&hash=1cbd3706ad4d8a1467250eeed0979f4a2afe8b7c)
Nevada's take on the red signal ahead warning sign is a static sign "Prepare to stop when flashing" with 2-4 yellow beacons. Examples:
- Pyramid Hwy (SR 445) in Sparks (http://goo.gl/maps/gVdK3)
- Las Vegas Beltway (CC 215) at US 95 in Las Vegas (http://goo.gl/maps/1DG1Y)
The difference is that these signs are wired to flash from a few seconds before the signal turns yellow to about 5 seconds after the signal turns green again. This helps prevent dilemma zone issues on one end, and accounts for the fact that the queue is not immediately released once the light turns green and stopping may still be necessary.
On original topic, here's a through signal on the opposing mast in Las Vegas, on Durango Drive at Grandbank Dr.
http://goo.gl/maps/8kFpF
There is a school crossing sign (older one with the lines) on the mast also because the intersection is in a school zone and the crosswalk at the intersection is a school pedestrian crossing on a "safe route to school".
The RED SIGNAL AHEAD signs would be the best as stated here. NJ uses them not only in blind spots, but where they're long gaps between signals like on US 22.
The problems is it has its advantages as well as its disadvantages. For example, to have it flash red a few seconds prior to the signal would be great as it forewarns drivers of the signal to about change, however on the same note in may encourage some drivers to speed up in hopes of making the intersection prior to it changing to red.
Osceola County, FL uses a flashing light on EB Osceola Parkway approaching Michigan Avenue in Kissimmee, FL. However the light only flashes when the intersection signal is red, but does not flash on green. So it combines both principles together. The only problem is that a railroad bridge obstructs the view of the signal (hence the purpose of the assembly) and it only flashes after the light turns completely red. Meanwhile you could be traveling at cruising speed and see the sign not flashing and then you arrive over the hump and then you have to slow down. Or worse yet you still have cars stopped from the previous red signal, as Florida is great for slow moving starts after signal changes to green.
Here's a good example of a great usage of this in Bend: http://goo.gl/maps/lLuyn It's on the far left mastarm too, a more extreme example. Around this curve though, I can affirm that it's quite necessary, really glad it's there.
Here is one that I took at an intersection in Manville, NJ with not only one, but two left side signal heads at an awkward intersection. Also, the far left one has a doghouse protected left set up while the near left has a tower with the extra arrows.
http://www.flickr.com/photos/54480415@N08/8501174341/in/set-72157632833956641