Full Gantries where partial bridge or mast arm will do

[roadman65]

https://www.flickr.com/photos/54480415@N08/45493212364/in/album-72157675874106048

As you can see this structure was not needed completely.

[sprjus4]

VA-168 Southbound Exit 8 in Chesapeake, VA.

Seemed to do it just fine further north at Exit 10

[Ian]

https://www.flickr.com/photos/54480415@N08/45493212364/in/album-72157675874106048

As you can see this structure was not needed completely.

I notice that the empty space on the structure includes an extended catwalk with abandoned sign lights, which makes me think that there was once a sign present in said empty space. Either that, or MoDOT planned on installing a sign there, but never did.

[sprjus4]

https://www.flickr.com/photos/54480415@N08/45493212364/in/album-72157675874106048

As you can see this structure was not needed completely.

I notice that the empty space on the structure includes an extended catwalk with abandoned sign lights, which makes me think that there was once a sign present in said empty space. Either that, or MoDOT planned on installing a sign there, but never did.

Nothing there, even as far back as 2008.

https://www.google.com/maps/@38.7772268,-90.3526721,3a,75y,334.38h,82.14t/data=!3m6!1e1!3m4!1sw36iURCWCD4Tduv0kFhITQ!2e0!7i3328!8i1664

[JoePCool14]

Here's one on the IL-WI border on I-94:



I think this may have been a contractor mistake when the Russel Road and US-41 exits were rebuilt a few years ago. Not sure what they were thinking here.

[roadman]

VA-168 Southbound Exit 8 in Chesapeake, VA.

Seemed to do it just fine further north at Exit 10

To provide a cantilever support for the signs at Exit 8 would require a cantilever arm approximately 62 feet in length.  While such a structure could be designed, it is unlikely that most steel fabricators could provide an upright pole with the necessary wall thickness.  Providing a full span structure with the left upright in the median would also require guardrail or other protection for the sign structure, whereas extending the span across the full width of the roadway puts both uprights behind existing guardrail.

By contrast, the cantilever arm on the support at Exit 10 is only about 38 feet long.  For such sign supports, most DOTs consider the practical limit for arm length to be 40 feet.  Again, this is due to fabrication constraints with the support uprights and constructability considerations for the foundation.

[jbnv]

I passed under this one just a few hours ago.

[ErmineNotyours]

Since removed for construction of a light rail line in the carpool lanes, this pair has one gantry over just the main line, and one over both the carpool lanes and the main line.

This one used to have a full gantry for just the HOT lane toll information sign, but they've since added the "Lane ends, merge left" sign on the right.

[ozarkman417]

Recently passed under this one

SM-G965U

[fwydriver405]

There are two in Manchester, NH that I know of on the Granite St exit off on I-293/Everett Turpike:
Southbound
Northbound

[Big John]

Georgia will not accept new cantilever gantries.

[marleythedog]

I-75 South exit 74 has full gantries at 1/2 mile and exit point that are unnecessary. This exit used to be A/B southbound (parclo B3?), so there used to be two signs at these points. However, at the same time that 75 was widened, the loop ramp was dropped to make a standard diamond, and the gantries erected then have never had two signs on them.

I-75 South exit 41 (also at 1/2 mile and exit point) - This seems like something they should have been able to do with a partial bridge. I wonder if they were contemplating pull-thru signs here because I-675 has just merged in?

[roadman]

Georgia will not accept new cantilever gantries.

That's been that way since the mid-1980s after GDOT had some anchor bolt failures.