Truss vs. tubular gantries by state

[PHLBOS]

CT seems to have stopped using the tubular only if the design of the project is being built today but was designed 10 years ago.  No new designs seem to have them.

This one is fairly recent (within the last 3 years).

[okroads]

Oklahoma has been using more tubular gantries in recent years. The new I-40 near downtown Oklahoma City uses them, along with I-35 through Norman and I-44 through part of Tulsa. All these sections of highway have been reconstructed or built during this decade.

[cl94]

New York is currently all-truss outside of airports and private property. NYSDOT will probably stick with trusses for a long time, while I've seen a tubular cantilever in an NYSTA plan set that should be installed within the next year or 2.

[Pete from Boston]

Is any state totally tubular?

[US81]

Is any state totally tubular?

Nah, dude, they're all pretty lame.


Sorry, couldn't resist. I'll see myself out now.

[Pete from Boston]

Is any state totally tubular?

Nah, dude, they're all pretty lame.


Sorry, couldn't resist. I'll see myself out now.

Rad.

[myosh_tino]

Is any state totally tubular?

Nah, dude, they're all pretty lame.


Sorry, couldn't resist. I'll see myself out now.

Back on topic, Nevada used tubular sign structures on I-80 through Reno.

[JakeFromNewEngland]

Connecticut has a mix of truss and tubular gantries. Most of the new signs in New Haven have been going up as tubular.

[Pete from Boston]

What is the name for this type of support (from kurumi.com)?

[OCGuy81]

Is any state totally tubular?

I want to say Arizona, maybe?

But I'm sure there are probably a few trusses around to prove me wrong, but I can't recall seeing any in AZ.

[Pete from Boston]

Is any state totally tubular?

I want to say Arizona, maybe?

But I'm sure there are probably a few trusses around to prove me wrong, but I can't recall seeing any in AZ.

It was a joke, actually, that probably flew right by anyone under a certain age. 

http://www.urbandictionary.com/define.php?term=Tubular

[OCGuy81]

Wow, clearly I need more coffee.

I did grow up in the 80s, and can't believe that one slipped by me! 

[Pink Jazz]

Is any state totally tubular?

I want to say Arizona, maybe?

But I'm sure there are probably a few trusses around to prove me wrong, but I can't recall seeing any in AZ.

There are a few older trusses in the Phoenix area, mainly along I-10 and US 60 (and possibly I-17 as well).  However all new installations use tubular gantries.

[luokou]

What is the name for this type of support (from kurumi.com)?

Monotube cantilever, I believe? Oregon uses both these and trusses.

[roadman65]

What is the name for this type of support (from kurumi.com)?

Monotube cantilever, I believe? Oregon uses both these and trusses.

The Lee Roy Selmon Expressway in Tampa, FL uses some of these at its exits east of Downtown.

[roadman]

As far as I can tell, Mass. only has tubular on roadways built as part of the Big Dig.  Never seen them elsewhere.

Connecticut has just about every type ever invented, including the two-piece cantilever setup that I'm sure has a more proper name.

Massachusetts specifications for sign supports only give very general guidance, and leave the exact support design to the fabricator/contractor.  As large tubular supports are more expensive than traditional truss or simple monotube designs, it's obvious why contractors go with the latter.  The Big Dlg was the lone exception to this rule, because the large tubular supports on that project were specified (by people with no experience in highway signing) for purely aesthetic reasons.

[roadman]

Delaware uses tubes, but not the kind normally used elsewhere.  It's more like an limbo assembly.  http://goo.gl/maps/dr77M .

I've seen similar set ups in Rhode Island, Mass, and New Hampshire.

Those examples are simple monotubes, and not a true tubular design.

[wriddle082]

I've never seen tubular gantries in Kentucky or either of the Carolinas, and have only seen them in Tennessee along the ring road around the Nashville International Airport.  In general, they seem to be very rare around the Southeast, which is probably why I enjoy seeing them whenever I visit Colorado.

[hbelkins]

Speaking of Kentucky, it's the only place I've seen that uses what I've seen called an "erector set" support for overheads.

[roadman]

Box truss and trichord uprights for cantilever supports used to be common in Massachusetts until the mid-1970s.  Massachusetts stopped using the design, principally for asethetic reasons, when they stopped allowing aluminum sign supports (due to issues with premature fatigue).

There are a small number of trichord upright cantilever supports still in place on sections of I-495 - they are planned to be replaced as part of current and future sign replacement projects.

And to the designer of the new 667 overhead sign in the second photo - what were you thinking (or perhaps drinking?) by placing 'Truck' above 'South' instead of above the shield (like on the ground-mount sign)?

[TEG24601]

Washington State seems to use a lot of tubular, at least from what I've seen.

There seems to be a wide variety actually.  Truss is the most common, then there is a lot of tubular down South, around Vancouver.  New installations are square tubes, which may be for strength, and ease of mounting reasons.

[Vincent]

Monotube cantilever, I believe? Oregon uses both these and trusses.

Correct. Oregon DOT standard is monotubes for cantilevered supports and trusses for sign bridges.

As always there's a few site specific exceptions. This giant truss cantilever on US 26 is one of my favorites: https://goo.gl/maps/xnkHK

[jakeroot]

Washington State seems to use a lot of tubular, at least from what I've seen.

Like Arizona, Washington does not use truss anymore.  I wouldn't call our gantries tubular, since it has four sides and the corners are 90 degree turns versus curved (for tubes). They are monotube, for sure. But not tubular.


Image courtesy of Interstate-Guide.com

British Columbia uses a very similar setup to Delaware:


Image courtesy of Vancouver Sun

EDITED to add quote

[roadman]

The Washington State example in the first photo is known as a welded box beam structure.  Boston's old elevated Central Artery had similar structures for its overhead signs.

The British Columbia example in the second photo would be considered a simple monotube, as the uprights and horizontal member are separate pieces.

[PHLBOS]

Box truss and trichord uprights for cantilever supports used to be common in Massachusetts until the mid-1970s.  Massachusetts stopped using the design, principally for asethetic reasons, when they stopped allowing aluminum sign supports (due to issues with premature fatigue).

There are a small number of trichord upright cantilever supports still in place on sections of I-495 - they are planned to be replaced as part of current and future sign replacement projects.

Aren't there still some trichord cantilever supports along I-95 between Topsfield/Danvers (Exit 50/US 1) and Byfield/Newbury (Exit 55/Central St.)?  GSV still shows them circa 2011. 

You (Roadman) know this, but for those that don't; those date back to when I-95 was widened to 8-lanes during the mid-1970s.