Guide Sign Panel Types

[J N Winkler]

Furthering your aside... Would it be possible start a thread that shows in detail, via photos or plans sheets, the different types of large-scale sign construction methods? I'd love to get a better visual understanding of these different types.

Toward this end--and with an invitation to moderators to split this subthread to a separate thread on guide sign panel types in the General Highway Talk board--here are pictures of a damaged extrusheet sign in Ohio, showing how the horizontal sheets are fastened to the stiffener ribs (click for full-size images):

[Billy F 1988]

Ouch! Looks like some dumb nut left his or her dump bucket or something in the air to smack that much of the Cleveland guide off its support structure. Can't be anything natural, unless the DoT haphazardly fastened them.


That reminds me of this. I browsed the Wyoming shield gallery and stumbled upon this big chunk of the I-25 guide sign near Douglas. I didn't shoot this picture. Jeff Royston did.


An uber-close up of the fallen I-25 Business panel. Half of the "u" is cut off, you can see "g l a" and "MILE" on that panel in the top picture. The left edge of the I-25 Business shield is also chopped. This is new material, too. WYDOT apprently was just overlapping the erroneous BGS panel put up before this came down and whatever happened here surely shows you that it wasn't fastened properly or maybe the adhesive behind the sheet became contaminated or something. That's well over $1000 of this material.

[cpzilliacus]

Maryland has been using extruded panels for many years.

Virginia never used them until recently.

[SignBridge]

I don't understand. I assume the stiffeners provide strength to the sign panel, right? So why don't all states need to use them? New York (for example) never has. Do they possibly use a thicker sheet of metal?

[DaBigE]

Maryland has been using extruded panels for many years.

Virginia never used them until recently.

Huh, I had more or less assumed that extruded panels were the norm for freeway-sized signs. Wisconsin has been using them for as long as I can remember (referred to as "Type I" signs by the design engineers).

[J N Winkler]

I don't understand. I assume the stiffeners provide strength to the sign panel, right? So why don't all states need to use them? New York (for example) never has. Do they possibly use a thicker sheet of metal?

In this case the stiffeners hold the strips together and improve torsional resistance in the horizontal direction.  NYSDOT achieves a similar result by using horizontal Z-bars at much greater spacing behind the main sign panel.  (Virginia DOT has long used a similar support system.)  I don't know if the gauge of aluminum panel NYSDOT specifies differs from that used by Ohio DOT.

Huh, I had more or less assumed that extruded panels were the norm for freeway-sized signs. Wisconsin has been using them for as long as I can remember (referred to as "Type I" signs by the design engineers).

Extruded aluminum construction is quite common, but by no means universal:  cf. plywood substrates (still hanging on in Wyoming and Texas), formed-panel signs, laminated signs (used extensively in California and Pennsylvania)--and this is without getting into the many strange and wonderful methods for lending support and rigidity to flat sheet aluminum.  This may be the most exotic sign support design I have seen:

Back of ground-mounted exit direction sign at I-80 Exit 231 in Battle Mountain, Nevada

Panel joins are lapped with flat aluminum strips and there is framing, but a lot of the overall assembly's resistance to torsion comes from the vee brace behind the two posts.  (I do not know if this is a Nevada statewide standard.)

[Alps]

...why not just overlay the 25 shield?

[Roadsguy]

Seriously? A colored business shield?

[J N Winkler]

...why not just overlay the 25 shield?

I don't think they were trying to fix just the wrongly colored shield--it also looks like they were trying to change the legend from Series D to Series E Modified for primary destination and Series E for distance expression.  My question is:  why attempt this in the field rather than at the shop?

[roadfro]

This may be the most exotic sign support design I have seen:

Back of ground-mounted exit direction sign at I-80 Exit 231 in Battle Mountain, Nevada

Panel joins are lapped with flat aluminum strips and there is framing, but a lot of the overall assembly's resistance to torsion comes from the vee brace behind the two posts.  (I do not know if this is a Nevada statewide standard.)

The vee bracing has been staple of post-mounted freeway signs in Nevada as long as I can remember. I would guess that 90% or better of roadside BGSs along freeway-grade facilities in Nevada are of this style.

NDOT does seem to be starting to use some I-beams or other constructs, but these are usually in urban areas. The V bracing is still very prevalent.

[SignBridge]

Mr. Winkler's earlier post re: NYS sign construction inspired me to look at a few this week. And yes, they do use a few horizontal stiffeners but fewer than on extruded signs. Again, I'll take a guess that New York uses heavier thickness metal sheets than other states. Their hardware is much cleaner looking too.