Most Signals on a Mast Arm

[Zmapper]

I notice that 4 is usually the most common for large intersections with multiple left turn and straight lanes. 5 isn't that uncommon. But are there any intersections with 6, 7, maybe more on a single mast arm?

[roadfro]

It's not uncommon to see mast arms with 5 signal heads at larger intersections in Nevada.

With new and reconstructed signal installations in Nevada, designers typically follow the recommendations of the MUTCD and others which suggest providing one overhead signal face per lane of travel plus a far-side supplemental pole-mount face.  For most major arterials in the Vegas area and in some parts of Reno, this means 5 heads on the mast arm (3 through lanes plus dual lefts) at major intersections.

Even 6 signal heads on one mast arm is not all that uncommon in the Vegas area. 7 is the most I've seen on one mast arm (this is usually with 4 thru lanes, 2 lefts, and a supplemental left for the opposing thru facing backwards). Once there's more than 6 lanes in one direction, separate masts for the left turns are typically used, mounted on an additional pole placed in the median.

Examples from AA Roads:
*5 heads: EB Flamingo Road (SR 582) at Eastern Avenue, Las Vegas - an older signal, typical of the 80s (or older?). 3 thru heads, 2 left heads.
*7 heads: WB St. Rose Pkwy (SR 146) at Bowes Ave, Henderson - a newer signal from widening less than 7 years ago. 4 thru heads, 2 left heads, 1 rear-facing head for opposing left movement (look closely).


I don't think I've ever personally seen more than 5 signal heads on one mast arm anywhere else I've ever been, unless it was a monotube installation across the entire intersection.

[realjd]

Florida often will use big beefy mast arms and throw them diagonally across the intersection, mounting two directions worth of signals. Here's one near where I live with 6 signals.

I know there are other around with more, I just couldn't come up with any quickly. I'll keep thinking about it.

EDIT: Found one. US-192 at SR-A1A. 9 signals, and two of them are doghouses.

[1995hoo]

The longest one I can recall seeing, not counting diagonal arms with signals for multiple directions of traffic, has six fixtures on a single arm in Arlington, Virginia (link below). It always looks like it's going to fall over because the arm is so much longer than the support column:

http://maps.google.com/?ie=UTF8&ll=38.84229,-77.052484&spn=0.006192,0.016512&t=h&z=17&layer=c&cbll=38.842413,-77.052499&panoid=iKixIQrvun7rbH4Wo0ShIQ&cbp=12,1.43,,0,-0.41

Florida often will use big beefy mast arms and throw them diagonally across the intersection, mounting two directions worth of signals. ....

I hate the diagonal arms unless it's a really big intersection. If you're the first car waiting on line at the light, I find that a diagonal arm often puts the light too close to your car so that you have to bend down to see it. There are a few intersections like that around here where they've either used diagonal arms or they've put the lights on the near side of the intersection in a misguided attempt to economize by using two arms on a single support column. Unfortunately, Google Street View isn't really helpful in identifying those because the camera is mounted up above the roof and so has a completely different perspective than a driver would. The one you linked looks as though it's farther away from the people facing the light such that maybe it's not as much of an annoyance.

[realjd]

The one you linked looks as though it's farther away from the people facing the light such that maybe it's not as much of an annoyance.

There's a second mast arm for one of the directions to prevent this very problem. They're usually good around here at not having signals too high and close to be seen. There are a lot of intersections around where all of the signals are on a single diagonal span-wire (which is usually a disaster in other areas) but they move the stop lines back and otherwise design it intelligently enough to have full visibility.

[PAHighways]

The only one I can think of off the top of my head is at a five-way intersection in Monroeville which has six signals serving four of the directions.

[Bryant5493]

Floy Farr Parkway and Peachtree Parkway - Peachtre Peachtree City, Georgia


Be well,

Bryant

[Alps]

How about most on a span wire? I've seen at least eight (single wire for the whole intersection, 2 per direction) but am scratching my head as to where I was.

[Michael]

In a post on the "Signage pet peeves" thread, I mentioned a span wire in Auburn, NY with several signals.  I remember seeing a mast arm installation with several signal heads, but I can't remember where I saw it.

[hobsini2]

They just put in a newer signal at Eola Rd and Diehl Rd in Aurora.  Each "arm" has 5 signals.  That is not common in Illinois.