Hard to believe that montube gantries have been around for at least 45 years (saw my first ones on the TV show CHiPs). Even harder to believe that it took so long for their design to be used regularly across the country.
What states have adopted/changed to the use of monotube gantries for their overhead signs? Also, for the individual state, is it a sporadic placement, widespread, or is it a vanity design for a specific highway?
COLORADO: Slowly becoming the norm state-wide as new installs and replacements of older gantries.
NEW MEXICO: In-use Statewide.
OHIO: Sporadic, though really becoming the norm in the Toledo area.
UTAH: Seems to be the norm, and has been for quite a number of years, save for some exceptions (Legacy Parkway in SLC).
Others?
Quote from: thenetwork on May 23, 2020, 09:50:50 AM
UTAH: Seems to be the norm, and has been for quite a number of years, save for some exceptions (Legacy Parkway in SLC).
Every overhead gantry on Legacy is still monotube:
(https://i.imgur.com/SklAvMf.jpg)
And yes, they have been the norm since at least the mid-1980s (if not earlier). The I-80/I-215/Foothill interchange used to be full of original truss gantries, but those were all replaced a few summers ago. As far as I know, there are only five truss gantries still standing in the entire state - three at the I-15/I-70 interchange, and two at the SR 56 interchange in Cedar City.
I don't believe MO has any monotube gantries. I-15 in San Diego does have some distinctive peach-colored ones, but those are the only ones I know of in Socal.
OK seems to be installing them only in urban counties. There was a bridge project on I-35 where it crosses from Cleveland to McClain County. All of the gantries on the Cleveland side were monotubes, but the one on the McClain County side was a traditional truss.
Chicago has, along the Chicago Skyway mostly. Otherwise, ISTHA has a triangular gantry they use, and IDOT has a square gantry they use (both before and after the brown gantries of the 1980s and 1990s).
Some newer installs along NTTA toll roads (Bush Turnpike and Dallas N. Tollway especially) have monotubes, but they haven't completely replaced traditional gantries or roadside BGSes.
None on the INDOT or the Toll Road, but three local streets uses it near Interstate 465: Keystone Parkway SB @96th Street in Carmel, 86th Street, and 71st Street.
The Tampa Region in Florida uses monotubes on I-275, I-4, and FL SR 60.
The I-80 corridor through Reno has monotubes gantries throughout the area (only place in Nevada to use monotubes gantries).
PA has started using them within the last few years for replacements and where widening/reconstruction has taken place:
Along I-81 between I-83 and exit 72:
https://www.google.com/maps/@40.3231759,-76.8145894,3a,75y,288.94h,96.49t/data=!3m7!1e1!3m5!1sB2QwG3cFe-5GLh4R9IjrJg!2e0!6s%2F%2Fgeo2.ggpht.com%2Fcbk%3Fpanoid%3DB2QwG3cFe-5GLh4R9IjrJg%26output%3Dthumbnail%26cb_client%3Dsearch.revgeo_and_fetch.gps%26thumb%3D2%26w%3D96%26h%3D64%26yaw%3D205.66689%26pitch%3D0%26thumbfov%3D100!7i13312!8i6656?hl=en
On I-276/PA Turnpike approaching the Willow Grove interchange:
https://www.google.com/maps/@40.1585906,-75.1303806,3a,75y,55.78h,93.96t/data=!3m6!1e1!3m4!1sEJwNbdEIrGMdnvkOBSs4Fw!2e0!7i16384!8i8192?hl=en
In general, most southeastern states don't use them, with the exception of FL. I have seen exactly 0 in the Carolinas, GA, AL, LA, and MS. In TN, I have only seen them on the ring road serving Nashville International Airport. I cannot remember whether or not they exist in KY now because I want to say I saw some along the Ohio River Bridges project sites in the Louisville area.
California some sections uses Monotube gantries.
Quote from: Brandon on May 24, 2020, 12:14:39 AM
Chicago has, along the Chicago Skyway mostly. Otherwise, ISTHA has a triangular gantry they use, and IDOT has a square gantry they use (both before and after the brown gantries of the 1980s and 1990s).
ISTHA uses monotube gantries for the I-Pass ORT Toll Booth lanes. Also ISTHA has used monotube gantries at newer ramp plazas as well
Quote from: Brandon on May 24, 2020, 12:14:39 AM
Chicago has, along the Chicago Skyway mostly. Otherwise, ISTHA has a triangular gantry they use, and IDOT has a square gantry they use (both before and after the brown gantries of the 1980s and 1990s).
I never liked those ugly brown gantries. I'm glad Illinois is going back to the trusses. Now if only the stoplights on lesser roads where you don't need 3 signals on an arm would go back to the truss.
Quote from: ilpt4u on May 24, 2020, 02:04:35 PM
Quote from: Brandon on May 24, 2020, 12:14:39 AM
Chicago has, along the Chicago Skyway mostly. Otherwise, ISTHA has a triangular gantry they use, and IDOT has a square gantry they use (both before and after the brown gantries of the 1980s and 1990s).
ISTHA uses monotube gantries for the I-Pass ORT Toll Booth lanes. Also ISTHA has used monotube gantries at newer ramp plazas as well
For the toll plazas, yes. and it makes sense for the to use them for the I-Pass lanes. But ISTHA never uses them for the green sign gantries. They had the opportunity to switch to it recently with the widening of I-90 and the extension of the Elgin O'Hare 390 Tollway but didn't. BTW, the plazas on the Elgin O'Hare 390 Tollway are not the same style as the I-Pass lanes on say 294 or 355. Those are more rounded. These are more squared. https://www.google.com/maps/@41.9868679,-88.1300475,3a,75y,38.68h,95.25t/data=!3m6!1e1!3m4!1sqTrAUdZD1ngrKP7cdP1VMA!2e0!7i16384!8i8192?hl=en or this https://www.google.com/maps/@41.9844772,-88.0070691,3a,75y,262.62h,89.67t/data=!3m6!1e1!3m4!1ssZqBQg5kHfNuQS9G_UNlXw!2e0!7i16384!8i8192?hl=en
One thing ISTHA has changed recently is the Plaza signs. They used to be green like this at Boughton Rd Plaza 89 for the non I-Pass lanes. https://www.google.com/maps/@41.7332056,-88.0352473,3a,75y,163.41h,89.51t/data=!3m6!1e1!3m4!1sCFNgOLAdVFwANzH4eg_goA!2e0!7i16384!8i8192?hl=en
They are blue now at that plaza as of a feww weeks ago. Unfortunately, I do not have a pic of it yet.
For Arizona, monotube gantries are used almost everywhere. The South Mountain section of Loop 202 is the only new stretch of freeway that does NOT use the monotube style.
Quote from: hobsini2 on May 24, 2020, 03:58:35 PM
Quote from: ilpt4u on May 24, 2020, 02:04:35 PM
Quote from: Brandon on May 24, 2020, 12:14:39 AM
Chicago has, along the Chicago Skyway mostly. Otherwise, ISTHA has a triangular gantry they use, and IDOT has a square gantry they use (both before and after the brown gantries of the 1980s and 1990s).
ISTHA uses monotube gantries for the I-Pass ORT Toll Booth lanes. Also ISTHA has used monotube gantries at newer ramp plazas as well
For the toll plazas, yes. and it makes sense for the to use them for the I-Pass lanes. But ISTHA never uses them for the green sign gantries. They had the opportunity to switch to it recently with the widening of I-90 and the extension of the Elgin O'Hare 390 Tollway but didn't. BTW, the plazas on the Elgin O'Hare 390 Tollway are not the same style as the I-Pass lanes on say 294 or 355. Those are more rounded. These are more squared. https://www.google.com/maps/@41.9868679,-88.1300475,3a,75y,38.68h,95.25t/data=!3m6!1e1!3m4!1sqTrAUdZD1ngrKP7cdP1VMA!2e0!7i16384!8i8192?hl=en or this https://www.google.com/maps/@41.9844772,-88.0070691,3a,75y,262.62h,89.67t/data=!3m6!1e1!3m4!1ssZqBQg5kHfNuQS9G_UNlXw!2e0!7i16384!8i8192?hl=en
One thing ISTHA has changed recently is the Plaza signs. They used to be green like this at Boughton Rd Plaza 89 for the non I-Pass lanes. https://www.google.com/maps/@41.7332056,-88.0352473,3a,75y,163.41h,89.51t/data=!3m6!1e1!3m4!1sCFNgOLAdVFwANzH4eg_goA!2e0!7i16384!8i8192?hl=en
They are blue now at that plaza as of a feww weeks ago. Unfortunately, I do not have a pic of it yet.
Strange that PA uses monotubes for toll plazas, because the last latticework gantry I saw in Washington was for the photo toll equipment near Evergreen Point Bridge here. (https://goo.gl/maps/Kv13P3xD55P1gmSVA) This turned out to be a very temporary installation and they moved the equipment at bit to the west on to the same square monotubes the state has put up since the 80s.
When I was commuting to a job in 1994 I noticed something odd in the construction of a monotube sign. Where the horizontal and vertical tube met was connected with a cast aluminum bracket. Nothing odd about that, but when the installation was complete, they covered it with a sleeve that made it look like the tubes were welded together directly. Or maybe I'm imagining things, but I swear I saw that bracket and I now can't see any indications that the tubes aren't welded together.
Quote from: wriddle082 on May 24, 2020, 08:27:50 AM
In general, most southeastern states don't use them, with the exception of FL. I have seen exactly 0 in the Carolinas, GA, AL, LA, and MS. In TN, I have only seen them on the ring road serving Nashville International Airport. I cannot remember whether or not they exist in KY now because I want to say I saw some along the Ohio River Bridges project sites in the Louisville area.
I'm pretty sure the Ohio River Bridges projects did not feature any monotube gantries. I don't think I've ever seen any kind of signage like that in Kentucky at all, or Indiana for that matter.
Here is the first known case of a monotube gantry in California at the CA-118 freeway.
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fwww.asphaltplanet.ca%2FCA%2FCA%2F118%2FCA118_dv_43_west.jpg&hash=4a5b61868ea54086a7f6a337a43d6cde3a218f5c)
The first monotubes I saw in CA were when the I-15 Escondido bypass opened in 1977, the streetlights had a similar design:
(https://i.imgur.com/A7b8bQQ.jpg)
^^^^
Quote from: MarkF on May 25, 2020, 04:04:16 AM
The first monotubes I saw in CA were when the I-15 Escondido bypass opened in 1977, the streetlights had a similar design:
https://i.imgur.com/A7b8bQQ.jpg
Those almost appear to be rounded version of the
welded box monotubes (https://goo.gl/maps/GUC8QPCuSgBWCx2v8) that WSDOT uses prolifically. Unless I'm seeing the image incorrectly.
WSDOT uses their welded box monotube (https://goo.gl/maps/Z22EeoEFUQyn6ytKA) standard that doesn't seem to have a domestic equivalent (at least not full width). They are very similar to the gantries used in some European countries like Germany, France, Austria, Norway, or Sweden, although only in appearance. How WSDOT constructs their gantries, I really don't know. They must weld them on the spot or something.
There have been traditional monotubes installed in Washington State, but none for a good twenty years or so; examples here (https://goo.gl/maps/jhyqT178akX9pZcb7) and here (https://goo.gl/maps/GYCX2tszd2zM3ho8A) (and all along the WA-14 Freeway in general). All examples I'm familiar with are in Clark County, just across the river from Oregon.
So, to add to the list:
WASHINGTON STATE: curved monotube gantries used sparingly in southwest part of state; box monotube structures are current standard for all overhead gantries.
Here's a picture of Washington's current highway gantries...obviously not a traditional monotube design, but does it count for the purpose of this thread?
(https://i.imgur.com/V2DQSGb.jpg)
Also a curved monotube near Wenatchee. https://goo.gl/maps/YgdBkDwKyLm1D4g66
The only ones in MN were installed in 2008 along the I-35W St. Anthony Falls Bridge in Minneapolis. AFAIK they haven't been used since.
https://goo.gl/maps/JnHKdvZSTEesMn3f9
Quote from: ErmineNotyours on May 25, 2020, 11:30:42 PM
Also a curved monotube near Wenatchee. https://goo.gl/maps/YgdBkDwKyLm1D4g66
Sweet find! I had no idea there were any curved monotubes outside of Clark County. Although this is rather strange with the double monotube setup. This has to have been a one-off assembly.
Massachusetts used monotubes throughout the Big Dig project area, but hasn't put up a new one since, switching back to more traditional trusses.
Example: https://goo.gl/maps/jqu6EkNq1Srdp93D6
MassDOT did use single or double mast arms for overhead signs for a while, e.g.: https://goo.gl/maps/DnDB7jQhGH34Ax6o9 though it seems new installations usually use traditional trusses.
CTDOT seemed to use the curved monotube gantries from around 2000 to about 2010-2015. They are quite prominent on I-95, including the Q-Bridge project. However lately, they seem to have switched to a mixture of single chorded trusses (mostly to replace bridge mounted signage) and squared off tube gantries. It looks like the full chorded truss May be making a comeback, as I see several newish ones in a storage area that look like they're reserved for the CT 72 sign replacement/exit renumbering.
In Texas, they are pretty much standard in the El Paso District, but are less common in other parts of the state.
Comparing the west coast to the east coast, they are definitely more common there compared to the east coast with absolutely no such signage in states like GA, SC, NC, VA, MD, DE, NJ, etc.
I wonder what the advantage of using monotube signs are but they look uglier compared to the traditional trusses we use.
They're easier to fabricate, and probably use less material. Both of those would make them cheaper.
Quote from: Scott5114 on February 02, 2022, 11:25:59 PM
They're easier to fabricate, and probably use less material. Both of those would make them cheaper.
i think the ones here in colorado are just ... funny looking. there's probably structural/technical details that are beyond what i know, but they just look weird to me.
Quote from: tolbs17 on February 02, 2022, 11:14:36 PM
Comparing the west coast to the east coast, they are definitely more common there compared to the east coast with absolutely no such signage in states like GA, SC, NC, VA, MD, DE, NJ, etc.
I wonder what the advantage of using monotube signs are but they look uglier compared to the traditional trusses we use.
I also don't encounter monotube gantries on a regular basis, but I've never heard anyone say they're uglier than the trusses used in the Southeast.
One surprising monotube design I've seen that didn't last too long are some of the monotubes in Southern California (especially along I‐15 between San Bernardino and San Diego) that start at a slight angle from the ground then a not-so-tight horizontal turn up top.
Was that design not as reliable as the most common monotube designs?
I have to exclude Delaware. More monotube gantries are coming up when looking at the recent sign placements.
It seems like they are really common on I-15 specifically, at least more so than any other x0 or x5.
Quote from: jaehak on February 22, 2022, 11:56:54 AM
It seems like they are really common on I-15 specifically, at least more so than any other x0 or x5.
Eh, 25 might edge it out given all of its major population centers are in Colorado and New Mexico, which make heavy use of monotubes. I-15 has plenty in the California and Utah cities it passes through, but the other states along 15 (including Nevada with Las Vegas) don't really use them as far as I know.
Quote from: zachary_amaryllis on February 02, 2022, 11:35:07 PM
Quote from: Scott5114 on February 02, 2022, 11:25:59 PM
They're easier to fabricate, and probably use less material. Both of those would make them cheaper.
i think the ones here in colorado are just ... funny looking. there's probably structural/technical details that are beyond what i know, but they just look weird to me.
Personally, I think trusses are far uglier than monotubes which I find simple and elegant.
Quote from: jaehak on February 22, 2022, 11:56:54 AM
It seems like they are really common on I-15 specifically, at least more so than any other x0 or x5.
Now I'm kind of wondering which interstate is the longest without monotubes. So far, with the longest overall...
I-90: box monotubes in WA
I-80: monotubes in UT, and possibly CA as well
I-40: monotubes in NM
I-10: monotubes in NM and AZ, and possibly CA?
I-70: monotubes in CO and PA
I-95: monotubes in PA, and maybe FL?
I-75: monotubes in OH, and maybe FL?
I-94: and... i'm stuck here
Quote from: SkyPesos on February 22, 2022, 02:04:20 PM
Quote from: jaehak on February 22, 2022, 11:56:54 AM
It seems like they are really common on I-15 specifically, at least more so than any other x0 or x5.
Now I'm kind of wondering which interstate is the longest without monotubes. So far, with the longest overall...
I-90: box monotubes in WA
I-80: monotubes in UT, and possibly CA as well
I-40: monotubes in NM
I-10: monotubes in NM and AZ, and possibly CA?
I-70: monotubes in CO and PA
I-95: monotubes in PA, and maybe FL?
I-75: monotubes in OH, and maybe FL?
I-94: and... i'm stuck here
I-10 uses monotubes in the El Paso district of Texas. The El Paso district seems to like monotubes.
I-40 also has monotubes in Arizona.
I-35, I-40, and I-44 all have monotubes at various places in OK.
Quote from: SkyPesos on February 22, 2022, 02:04:20 PM
Quote from: jaehak on February 22, 2022, 11:56:54 AM
It seems like they are really common on I-15 specifically, at least more so than any other x0 or x5.
Now I'm kind of wondering which interstate is the longest without monotubes. So far, with the longest overall...
I-90: box monotubes in WA
I-80: monotubes in UT, and possibly CA as well
I-40: monotubes in NM
I-10: monotubes in NM and AZ, and possibly CA?
I-70: monotubes in CO and PA
I-95: monotubes in PA, and maybe FL?
I-75: monotubes in OH, and maybe FL?
I-94: and... i'm stuck here
The Chicago Skyway in IL also uses monotubes.
Quote from: Scott5114 on February 22, 2022, 02:49:35 PM
I-35, I-40, and I-44 all have monotubes at various places in OK.
I-35W in Minneapolis has monotubes, the only such in Minnesota.
I-94 unless it has some in downtown Detroit might qualify. I've driven all of it except there, basically.
Quote from: TheHighwayMan394 on February 22, 2022, 06:45:14 PM
Quote from: Scott5114 on February 22, 2022, 02:49:35 PM
I-35, I-40, and I-44 all have monotubes at various places in OK.
I-35W in Minneapolis has monotubes, the only such in Minnesota.
I-94 unless it has some in downtown Detroit might qualify. I've driven all of it except there, basically.
I don't see any monotubes on a GSV look on I-94 in downtown Detroit. So I think that makes it the longest interstate without monotubes, with the second and third longest to be I-20 and I-55 to the best of my knowledge. Someone can correct me on either (or both) if necessary.
I don’t believe that I-64 has any monotubes, and it’s a pretty long interstate.
Also add Tennessee, or at least TDOT, to the list of who doesn’t use monotubes. There may still be some custom monotubes being used on roads serving Nashville International Airport (BNA), but these are not TDOT installs. And they look(ed) a bit different than most other states’ monotubes in that the 90° curve was a little sharper and they were painted white.
Quote from: skluth on February 22, 2022, 01:18:47 PM
Quote from: zachary_amaryllis on February 02, 2022, 11:35:07 PM
Quote from: Scott5114 on February 02, 2022, 11:25:59 PM
They're easier to fabricate, and probably use less material. Both of those would make them cheaper.
i think the ones here in colorado are just ... funny looking. there's probably structural/technical details that are beyond what i know, but they just look weird to me.
Personally, I think trusses are far uglier than monotubes which I find simple and elegant.
Clearly not all states are on board to use them.... But I will say this: They are nicer compared to the trusses used in Connecticut.
Caltrans D4 uses a lot of monotubes. I-680 in Contra Costa County is almost all monotube, with very few exceptions. Example from the exit nearest my home:
https://www.google.com/maps/@37.9372089,-122.0601197,3a,75y,11.16h,92.13t/data=!3m6!1e1!3m4!1shoCoAopZ968L9xEZGCMBqw!2e0!7i16384!8i8192
Disadvantages of monotube gantries is that this can happen.
https://www.cnn.com/videos/bestoftv/2012/08/21/vo-calgary-highway-sign.global-news
Now you know why some states (especially coastal ones) don't use them.
Quote from: tolbs17 on February 23, 2022, 02:03:19 PM
Disadvantages of monotube gantries is that this can happen.
https://www.cnn.com/videos/bestoftv/2012/08/21/vo-calgary-highway-sign.global-news
Now you know why some states (especially coastal ones) don't use them.
That monotube is much smaller (thinner) than the monotubes used in places like California or Utah, and are much less likely to flex in a manner like that.
Quote from: jakeroot on February 23, 2022, 03:42:39 PM
Quote from: tolbs17 on February 23, 2022, 02:03:19 PM
Disadvantages of monotube gantries is that this can happen.
https://www.cnn.com/videos/bestoftv/2012/08/21/vo-calgary-highway-sign.global-news
Now you know why some states (especially coastal ones) don't use them.
That monotube is much smaller (thinner) than the monotubes used in places like California or Utah, and are much less likely to flex in a manner like that.
Yep.
Here's the monotube in question (https://goo.gl/maps/2HLvr8nrWXhXFbg87). Compare it to a
typical Utah example (https://goo.gl/maps/EujfjTLzivXMUAE69) and you'll almost instantly notice the difference. A lot of monotubes in states that use them are also this
even beefier variant (https://goo.gl/maps/X1nj5tX2PudJNL2fA) when they have to carry larger signs (of course, CA probably doesn't have any signs tall enough for that).
The wind argument is also silly when you consider a state like New Mexico. The state has enough of a wind concern that they mount 99.5% their traffic signals horizontally on mast arms, yet they are also pretty much exclusive monotube users...
I wish more states would use the double-tube variant (duotube gantry?) more often. It just looks more visually pleasing and sturdy to me. I know intellectually that a monotube is usually strong enough to hold a sign just fine, but visually the signs look way too big for the pole.
Quote from: Scott5114 on February 23, 2022, 04:29:02 PM
I wish more states would use the double-tube variant (duotube gantry?) more often. It just looks more visually pleasing and sturdy to me. I know intellectually that a monotube is usually strong enough to hold a sign just fine, but visually the signs look way too big for the pole.
I used to dream about such. It would definitely look pleasing to the eye, even if the lower tube was smaller than the upper.
Quote from: SkyPesos on February 22, 2022, 02:04:20 PM
Quote from: jaehak on February 22, 2022, 11:56:54 AM
It seems like they are really common on I-15 specifically, at least more so than any other x0 or x5.
Now I'm kind of wondering which interstate is the longest without monotubes. So far, with the longest overall...
I-80: monotubes in UT, and possibly CA as well
Monotubes are also on I-80 in Nevada through Reno/Sparks. To date, it's Nevada's first and only foray with montube gantries. I'm pretty sure it was part aesthetic design choice with the rebuild circa 2010, and part because NDOT hadn't yet figured out the best way to mount a large APL to their standard truss (that project also had NDOT's first 2009 MUTCD compliant APLs).
Quote from: SkyPesos on February 22, 2022, 07:55:09 PM
I don't see any monotubes on a GSV look on I-94 in downtown Detroit. So I think that makes it the longest interstate without monotubes, with the second and third longest to be I-20 and I-55 to the best of my knowledge. Someone can correct me on either (or both) if necessary.
On second thought, do these monotubes used for open road tolling on I-94 count (https://www.google.com/maps/@42.4321017,-87.9522611,3a,43y,133.08h,92.15t/data=!3m6!1e1!3m4!1szt3UYTRBj7RplqtBFYi5rQ!2e0!7i16384!8i8192?hl=en), or does a BGS have to be attached to one?
The only examples of monotube gantries in Massachusetts are all in Boston.
Here's an example on the Mass Pike at Exit 134
https://www.google.com/maps/@42.3464337,-71.0617479,3a,75y,106.56h,72t/data=!3m6!1e1!3m4!1s1b3SBwXUd1M8gy2RjEXbFQ!2e0!7i16384!8i8192
Exits 135 and 137 also have them as well as on I-93 north leaving the Tip O'Neill Tunnel and around Andrew Square southbound.
I-80 at CA-12 interchange at the Cordelia Truck Scales uses Monotube gantry.
(https://www.aaroads.com/ca/380/i-380-w-exit-005-02.jpg)
Here is AARoads shot of another Monotube Gantry this time near San Francisco International Airport on I-380.
Rare monotube gantry in NC
https://goo.gl/maps/qhLtb8cx6G9nDZmu6