"Multiplex?"

[kphoger]

"BGS" was met with blank stares when I used it among highway engineers, though.  They had some crazy, official-sounding, multi-word term for a BGS (which they only vaguely remembered, by the way).  What losers.

[NE2]

Whatever. "Guide sign" is a precise enough replacement, and "big green sign" when talking to the unwashed masses.

[hbelkins]

I have used "multiplex" in the past but the term began grating on me in later years.

Our engineers use the term "panel signs" to refer to guide signs or "big green signs."

[J N Winkler]

To add to Jake's comments regarding button copy--I am sure I have seen reflective button letters (or similar phrasing) in Caltrans documentation.  AGA letters and AGA copy have also been used (the American Gas Accumulator Co., which was subsequently absorbed into Stimsonite, was the leading manufacturer of framed button copy).

To add to NE2's comments about big green sign:  the full phrase is indeed readily understandable by non-enthusiasts (though big is a decidedly non-U word), but the acronym is not.  I usually use the phrase large guide sign when I wish to refer to guide signs that are sufficiently large in format to be used on freeways or expressways, and D-series sign when I want to refer to smaller guide signs that are used on conventional roads (i.e., any public road that is not a freeway, expressway, or some other type of special-purpose facility).  D-series signs get their name from the fact that the MUTCD sign codes for them start with D.

To add to what H.B. and Kphoger say about BGS, the actual terminology used by most state DOTs is generally based on substrate type.  In Kentucky, for example, panel sign can be taken to mean "large guide sign" because KyTC uses sheet aluminum for typical D-series applications.  That approach would not work in other states like California and Washington, because the full panoply of substrate types is used for both conventional-road and freeway/expressway applications.  Other state DOTs talk in terms of type classification--"Type A," "Type B," etc. in many states, or even "Type I," "Type II," "Type III," etc. in Michigan--which are generally composite references to substrate type, sign sheeting type, or even mounting position (overhead versus ground-mounted).  The cutoffs between the types are based on how standard bid items are defined.  (Most state DOTs ask contractors bidding on signing work to quote a unit price of so many dollars per square foot for quantities that are expressed as total square feet of a given sign type.  The only exception I am aware of is Florida DOT, which has separate bid quantities for various sign types by square foot range, and asks contractors to quote on a "per each" basis:  so many signs with sizes ranging from 60 to 80 SF, so many signs with sizes ranging from 80 SF to 100 SF, etc.)

In Kansas the phrase "High performance sheeting" is, rather oddly, usually a clue that small signs (including D-series signs) are being talked about, since KDOT tends to avoid that phrase in bid items for large guide signs (even though it is my understanding that the same type of sheeting is used for them).

[agentsteel53]

D-series signs get their name from the fact that the MUTCD sign codes for them start with D.

here I always thought you called them that because an older spec of them had Series D all-caps letters.

interestingly, the old old internal reference code for such a sign in California - dating back to 1934 - is D as well.  not the specification sheet, which has them as a subset of the G-series, but the actual stamp on the back.  D10D181 is a sign that just appeared on eBay.  1937, district 10, "direction or distance", serial number 181.