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Different generations of button copy signs in CA

Started by joshI5, December 29, 2018, 04:21:09 AM

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joshI5

There plenty of posts here discussing CA's renowned button copy signs. From what I can tell there seem to be two different types of button copy signs in use throughout the state: 1) the older, porcelain enamel signs and 2) the slightly newer, similar-looking button copy that seem to have the same forest-green backgrounds but with a different type of background sheeting. The buttons/lettering in the latter also appear much cleaner (some of them looking brand new, imo) with less dirtiness and rust seeping from the letters, as is the case in almost all of the older porcelain enamel signs still in use.

Does anyone know when Caltrans made the switch between the two types of button copy signs? I know CA introduced retroreflective BGSs in 1999, and the porcelain enamel signs around 1960 (?), but I couldn't find much regarding when Caltrans phased in the newer type of button copy that is clearly a bit different from the original signs. My ill-informed guess would be the mid-70s or early 80s?

Also, what type of material is the 'newer generation' of button copy signs made from? Is it aluminum, and is the signing practice much different from the porcelain enamel process albeit still being button copy? Also am wondering if the material comprising the newer button copy signs are less prone to the type of rust and grime that all the porcelain signs seem to have experienced, or is it simply just age? Some of those newer forest-green button copy signs look like they could have been put up just yesterday.

Here are pictures of the two different types to illustrate my point:





The difference is subtle, but clearly a different material is used for at least the backgrounds of each sign. Also, the lettering in the latter looks more pronounced.

Also, just for the heck of it, has CA ever used button copy with lighter-green reflective sheeting, like other states used to?


myosh_tino

Quote from: joshI5 on December 29, 2018, 04:21:09 AM
Also, just for the heck of it, has CA ever used button copy with lighter-green reflective sheeting, like other states used to?

AFAIK, the answer is "no".
Quote from: golden eagle
If I owned a dam and decided to donate it to charity, would I be giving a dam? I'm sure that might be a first because no one really gives a dam.

Max Rockatansky

When did California remove Button Copy from it's MUTCD?  I noticed that the CA 168 Freeway has a ton of button-copy BGSs on surface streets that are definitely less worn than typical fare. 

MarkF

Many of the porcelain enamel signs went up without button copy.  In the early 1980s, most of these signs had button reflectors glued to the signs as a retrofit so that sign lighting maintenance could be reduced.  That 605 sign is an example of the glued on reflectors.  I recall that signs that didn't get the reflectors added seemed much cleaner, the glued on reflectors attracted more road grime than the smooth surface.

myosh_tino

Quote from: Max Rockatansky on December 30, 2018, 12:36:38 AM
When did California remove Button Copy from it's MUTCD?  I noticed that the CA 168 Freeway has a ton of button-copy BGSs on surface streets that are definitely less worn than typical fare.

Looking at Caltrans' Traffic Operations Policy page on its website, there are memos dated March of 1999 that relate to sheeting material for guide signs (links to those memos below).  In those memos it states that ASTM Type III or IV would become the sheeting material of choice when the next guide sign contract was awarded (around July of 1999).  In the memo dated March 16, 1999, it gave the districts the authority to begin purchasing and ordering signs using the retroreflective sheeting.  Apparently this was all done in anticipation of the release of the 2000 Federal MUTCD which mandated the use of retroreflective sheeting on signs.

http://www.caltrans.ca.gov/trafficops/policy/SheetingMaterialGuide.pdf
http://www.caltrans.ca.gov/trafficops/policy/GuideSign(Sheeting).pdf

FWIW, that policy page contains memos, directives and letters going all the way back to 1987!  :-o
Quote from: golden eagle
If I owned a dam and decided to donate it to charity, would I be giving a dam? I'm sure that might be a first because no one really gives a dam.

J N Winkler

I think the abandonment of porcelain enamel on steel in favor of aluminum occurred around 1972.  I have found letters and reports from that approximate date in the traffic signing file kept at the Caltrans Library in Sacramento discussing the problems of maintaining pigment consistency against aluminum.

While overhead signs were initially not reflective because it was expected that external illumination would always be provided, there was an energy-conserving lights-out initiative in the mid-1970's that resulted in button reflectors being epoxied onto older signs without retroreflectorization (as MarkF explains), while framed button copy became the norm for new signs.

For ground-mounted signs, retroreflectorization of one kind or another has been provided for foreground elements at minimum since at least the late 1940's, and many of the technologies that have historically been used--retroreflective sheeting (Scotchlite), framed button copy (AGA letters), and embedded reflectors--have coexisted for much of this time.  Caltrans used, and continues to use, multiple different types of sign substrate (e.g. laminated panel, formed panel with RSPFs, single sheet), which makes it complicated to speak in terms of "generations" other than for the break in 1972 (Great Redrawing, abandonment of porcelain enamel on steel) and 1999 (abandonment of button copy).
"It is necessary to spend a hundred lire now to save a thousand lire later."--Piero Puricelli, explaining the need for a first-class road system to Benito Mussolini

Max Rockatansky

Quote from: myosh_tino on December 30, 2018, 12:25:37 PM
Quote from: Max Rockatansky on December 30, 2018, 12:36:38 AM
When did California remove Button Copy from it's MUTCD?  I noticed that the CA 168 Freeway has a ton of button-copy BGSs on surface streets that are definitely less worn than typical fare.

Looking at Caltrans' Traffic Operations Policy page on its website, there are memos dated March of 1999 that relate to sheeting material for guide signs (links to those memos below).  In those memos it states that ASTM Type III or IV would become the sheeting material of choice when the next guide sign contract was awarded (around July of 1999).  In the memo dated March 16, 1999, it gave the districts the authority to begin purchasing and ordering signs using the retroreflective sheeting.  Apparently this was all done in anticipation of the release of the 2000 Federal MUTCD which mandated the use of retroreflective sheeting on signs.

http://www.caltrans.ca.gov/trafficops/policy/SheetingMaterialGuide.pdf
http://www.caltrans.ca.gov/trafficops/policy/GuideSign(Sheeting).pdf

FWIW, that policy page contains memos, directives and letters going all the way back to 1987!  :-o

That might explain why I'm seeing the button-copy signs near the western terminus of the CA 168 freeway, I believe that was the first section completed.  I want to say it opened fully in 2002 and the more east you go the more modern the signage gets.



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