early interstate shield specs

[agentsteel53]

edit: moved this reply out of the game topic so we can discuss interstate shield specs here, while working on design problems over there

If this game involves counting points, I'd be grateful if any points I get could be distributed to others on an equal basis--I am in this to solve design problems, not to compete.

I do not have any plan to award points; just to assign a winner, who will then give the next design challenge.

I have followed the design brief as given (down to remastering the Interstate shield from the 1958 specifications, since I don't have access right now to the later edition)

'61 spec is '58 spec, except with the 18x18 size omitted, so that is correct.  

I am also not convinced that Arizona in 1961 was using state-name Interstate shields on overhead guide signs.  

the video capture is from a 1971 film.  It may just be my imagination, but I thought the state name was on the shields in the photo.  The 1958 spec does say that the state name should be omitted from guide sign shields (but the small numbers should be kept), and some states obeyed more rigorously than others.  

I want to cross-check against the standard plan sheets from contemporary signing plans to see whether Arizona at that time had a design for the guide sign shield which omitted the state name.

Some states had the state name, others did not, but they all had the small numbers (8" numbers on the 24" blank).

I know for a fact that California had guide sign Interstate shields without the state name from 1959 at the very least, and probably earlier.  (California actually had five standard widths of guide sign shield in 1959, to accommodate "5," "10," "40," "80," and "480."

now this I did not know!  Do you have a copy of this spec?  If so, can you email it to me please?  I have never been able to note a difference between one- and two-digit shields just based on looking at photos.  California, BTW, had the shield as early as 1958.  

www.aaroads.com/shields/show.php?image=CA19580051t100050.jpg&search=5

CA introduced a smaller crown and larger blue field, as can be seen on that photo, and in better detail on this 1960 I-5 shield:

www.aaroads.com/shields/img/CA/CA19580054i1.jpg

(as far as I know, the original margins and field sizes, combined with larger numbers - 10" on a 24" blank - with no state name style was introduced by Idaho.  I have seen that style used in 1968.  Minnesota is a possibility as well; I have seen a shield of that style trailblazing the Duluth I-35, which I think was finished by 1971.)

The original 1959 I-480 shield does not have the same shape as either the three-digit shield Caltrans adopted in 1961 or the modern three-digit Interstate shield.  

Is that the 21x18 size (and scaled proportionally)?  As opposed to California's 1962 (1961?) 30x25, or the federal 30x24?

California's 1971 MUTCD - the latest interstate shield revision - still contains the possibility of 21x18; and new ones are being put up all the time!

[agentsteel53]

one thing I did notice is that the original photo has the two left shields with Series E numbers, and it looks like the 410 as well, but that is a bit tougher to discern with the perspective.  I think that was to facilitate the use of standard button copy elements.  

that is not the 1958 interstate shield spec, as far as I know, but the '58 manual specifies the use of retroreflective shields (similar to pole-mounted shields, just without the state name) as opposed to button copy.  

(also, while we're vaguely on the topic - does anyone know what the I-70 shields looked like on the Kansas turnpike in 1956?  I have heard those were the first shields to get put up.  My '58 manual says that the interstate shield was adopted August 14th, 1957, so what happened before that?  Or was the Turnpike signed in Aug '57?)

[J N Winkler]

I think the Turnpike was just the Turnpike until the AASHO manual was released.  There was a shield for the Turnpike which I found in a 1950's book on the then recently built public-authority turnpikes and it was different from the current one--it was wider on the top than on the bottom, like an upside-down vase, and had a sunflower design and an abbreviation of "Kansas Turnpike" somewhere.  (I have looked for this book, believe me, but I have never managed to find it again.)

Re. the I-410/Buckeye Rd. sign, I did see the wide digits on the shields (I think they are Series E Modified) but opted to do the signs by the book.  ADOT did use Series E Modified on shields back in the early 1960's--not just Interstate shields, but also US and state route shields.

The original publicity for the Interstate shields in Traffic Engineering etc. in 1958 showed Scotchlite shields.

Regarding the California guide sign Interstate shields of 1959, it turns out I exaggerated a little--in fact there were only three standard widths proportionate to height, although there were differences in the allowable sizes, including border widths.  Going through the drawings (which I will email in a moment):

*  I-5:  36" x 36", border width 1 1/8", digit height 16" Series D

*  I-10:  24" x 24", border width 3/4", digit height 12" Series D

*  I-40:  40" x 36", border width 1 1/8", digit height 16" Series D

*  I-480:  48" x 40", border width 1 1/8", digit height 16" Series D

*  I-80:  essentially the same as I-5 shield design (but with two digits)

In all of these shields, the state name is absent.  The designs also don't show button reflectors, unlike other designs of the same time period which do show button reflectors in the shields and legend for signs which were meant to be used with button copy.  Therefore I think they were originally intended for porcelain-on-steel overhead signs.

AIUI, the Caltrans sign specs leave the option of 18" x 21" shields not just for Interstates, but also for US and state routes, and this is designed mainly for use on conventional roads (e.g. the small signs with strap reinforcement which tell you route X is coming up, go here for EAST, go there for WEST).

Edit:  I rooted through my old Arizona DOT sign design sheets and found some 1962-vintage specs for Interstate shields.  There were variations with and without the state name, but on the shields without the state name, the digits were proportionately a little higher than on the state-name shields but with enough clear blue above the digits to fool your eyes into thinking the state name could fit there.

[agentsteel53]

I think the Turnpike was just the Turnpike until the AASHO manual was released.  There was a shield for the Turnpike which I found in a 1950's book on the then recently built public-authority turnpikes and it was different from the current one--it was wider on the top than on the bottom, like an upside-down vase, and had a sunflower design and an abbreviation of "Kansas Turnpike" somewhere.  (I have looked for this book, believe me, but I have never managed to find it again.)

you must mean this

1957 official Kansas state map:
www.aaroads.com/shields/show.php?image=KS19540352t400350.jpg&search=35

and an example shield:
www.aaroads.com/shields/show.php?image=KS19540351t400350.jpg&search=35

the official name for that shape is "coffin".  There's a reason why they changed it to a square within a few years!

Re. the I-410/Buckeye Rd. sign, I did see the wide digits on the shields (I think they are Series E Modified) but opted to do the signs by the book.  ADOT did use Series E Modified on shields back in the early 1960's--not just Interstate shields, but also US and state route shields.

this was on pole-mount shields, or just the ones on green/black signs?  Here is another old picture, with black signs with outline shields.  Looks like Series C on these.

www.aaroads.com/shields/show.php?image=AZ19650891t300930.jpg&search=93

The original publicity for the Interstate shields in Traffic Engineering etc. in 1958 showed Scotchlite shields.

I think the states kind of all independently hit upon using button-copy shields.  I am thinking Stimsonite made a sample and sent it to every DOT and it took off.

Regarding the California guide sign Interstate shields of 1959, it turns out I exaggerated a little--in fact there were only three standard widths proportionate to height, although there were differences in the allowable sizes, including border widths.  Going through the drawings (which I will email in a moment):

*  I-5:  36" x 36", border width 1 1/8", digit height 16" Series D

*  I-10:  24" x 24", border width 3/4", digit height 12" Series D

*  I-40:  40" x 36", border width 1 1/8", digit height 16" Series D

*  I-480:  48" x 40", border width 1 1/8", digit height 16" Series D

*  I-80:  essentially the same as I-5 shield design (but with two digits)

got the specs; thank you for mailing them along!  The I-10 at first glance looks to be a direct 150% scale-up of the I-5 shield, including going from 3/4 to 9/8" margins... but why 16 and not 18" numbers?  Looking at the numbers on the drawing, not as specified in the text, they look to have the same proportions.

of course CA is badly known for having drawings mismatched from specified lengths and radii.  The 1957 US shield spec is notorious for drawing one shield shape and specifying another.  They took the 1952 shield spec verbiage, and the 1956 shield shape drawing, and mashed it together, and that is why there are ... three ... versions of Cal US shields out there to this day?  (Yep, there is a third.  Oh sweet headache Jesus.  Pray no one orders a modern CA US shield from me - oh wait, everyone does.  I just use the 1956 shape because I like it best!)

In all of these shields, the state name is absent.  The designs also don't show button reflectors, unlike other designs of the same time period which do show button reflectors in the shields and legend for signs which were meant to be used with button copy.  Therefore I think they were originally intended for porcelain-on-steel overhead signs.

that is indeed correct.  CA had underlit signs, and therefore eschewed button copy on the overheads.  I do not know what they used on the surface-level green or black signs, actually!  I have seen guide signs for US and state shields from that era (outline shields) but none for an interstate.  I would assume they had holes drilled in the porcelain through which buttons were placed, as they did with US and state shields, and text verbiage, but cannot confirm this. 

(In other news, I have a photo somewhere of a *black* guide sign for I-80/Reno in the Auburn area.  I do not know if it is a violation of AASHO specifications, or it came earlier in 1958 than the manual.   California switched to green signs from black halfway through 1959.)

The I-5 shield I linked to earlier that was intended for guide sign use, was actually surface mounted.  There is a 4x4 post mark on the back.  I think that was just installation error.

AIUI, the Caltrans sign specs leave the option of 18" x 21" shields not just for Interstates, but also for US and state routes, and this is designed mainly for use on conventional roads (e.g. the small signs with strap reinforcement which tell you route X is coming up, go here for EAST, go there for WEST).

The 18x18 shields are very, very rare.  I know of three surviving US-50s, all on the alignment bypassed by the freeway coming out of Sacramento, and a US-66 in an antique store in Arizona.  Have never seen an 18" spade, either white or green.

Edit:  I rooted through my old Arizona DOT sign design sheets and found some 1962-vintage specs for Interstate shields.  There were variations with and without the state name, but on the shields without the state name, the digits were proportionately a little higher than on the state-name shields but with enough clear blue above the digits to fool your eyes into thinking the state name could fit there.

are those an exact copy of the California shields, with the smaller word INTERSTATE and everything?  I see AZ also was using 30x25 shields as early as 1962 if that spec is to be believed.  (It says 1966 but one of the dates on it is 1962, so I am thinking it is a 1966 re-issue of a 1962 spec.)

[J N Winkler]

Thanks for links to the original Turnpike shields--yes, just as I remembered them!

Re. the I-410/Buckeye Rd. sign, I did see the wide digits on the shields (I think they are Series E Modified) but opted to do the signs by the book.  ADOT did use Series E Modified on shields back in the early 1960's--not just Interstate shields, but also US and state route shields.

this was on pole-mount shields, or just the ones on green/black signs?

I know ADOT used Series E Modified on guide sign shields, but I have no information on independent-mount shields (the formal name for "pole mount").  The standard plan sheet I emailed you calls for Series D all the way down the line, but since I have sign design sheets which show Series E Modified in guide-sign shields, I am not sure how far to trust the standard plan sheets in relation to independent-mount shields.  I think they would have been fabricated with Scotchlite and so would have followed the standard plan sheet more closely than the guide sign shields, but that is just a guess.

I am not aware that ADOT ever used anything but green background for guide signs on roads signed as Interstates.  Certainly green (either reflective or nonreflective) is all I have ever seen in ADOT signing plans, going back to the early 1960's.

Here is another old picture, with black signs with outline shields.  Looks like Series C on these.

www.aaroads.com/shields/show.php?image=AZ19650891t300930.jpg&search=93

I am inclined to regard it as a late-1950's one-off, especially since it is hard to tell whether the installation is on a surface street.  Arizona SR 69 did eventually become I-17.

I think the states kind of all independently hit upon using button-copy shields.  I am thinking Stimsonite made a sample and sent it to every DOT and it took off.

I am pretty sure they must have done, though I haven't personally run across any samples.  I do know that they distributed a sort of catalogue which had details of the various button copy alphabets they sold.  I have run across a copy of it in the Caltrans library in Sacramento, but was not able to get a camera copy of it.

I understand that "Series D Modified" (not really ever one of the official FHWA alphabets) was originally a Stimsonite creation, to accommodate button reflectors.  When it was still using button copy, Arizona DOT standardized on Series D Modified for all-uppercase legend on freeway guide signs (cardinal direction words, distance expressions, exit tab legends, etc.) but changed over to Series E or Series E Modified for these applications with the conversion to retroreflective sheeting.

Regarding the California guide sign Interstate shields of 1959, it turns out I exaggerated a little--in fact there were only three standard widths proportionate to height, although there were differences in the allowable sizes, including border widths.  Going through the drawings (which I will email in a moment):

*  I-5:  36" x 36", border width 1 1/8", digit height 16" Series D

*  I-10:  24" x 24", border width 3/4", digit height 12" Series D

*  I-40:  40" x 36", border width 1 1/8", digit height 16" Series D

*  I-480:  48" x 40", border width 1 1/8", digit height 16" Series D

*  I-80:  essentially the same as I-5 shield design (but with two digits)

got the specs; thank you for mailing them along!  The I-10 at first glance looks to be a direct 150% scale-up of the I-5 shield, including going from 3/4 to 9/8" margins... but why 16 and not 18" numbers?  Looking at the numbers on the drawing, not as specified in the text, they look to have the same proportions.

My guess:  this is evidence of Caltrans getting ready to cheat with "mini" shields on overhead guide signs.  The I-10 shield would obviously never have worked as a main guide sign shield (as a general rule, I think only the shields with 1 1/8" borders were intended for this function), but might have been used when shields were desired on multiple lines, or a shield had to be put near a particular downward-pointing arrow to give advance notice of a future split (which is essentially what Richard Ankrom did with his I-5 shield in the downtown LA interchange complex).

In all of these shields, the state name is absent.  The designs also don't show button reflectors, unlike other designs of the same time period which do show button reflectors in the shields and legend for signs which were meant to be used with button copy.  Therefore I think they were originally intended for porcelain-on-steel overhead signs.

that is indeed correct.  CA had underlit signs, and therefore eschewed button copy on the overheads.  I do not know what they used on the surface-level green or black signs, actually!  I have seen guide signs for US and state shields from that era (outline shields) but none for an interstate.  I would assume they had holes drilled in the porcelain through which buttons were placed, as they did with US and state shields, and text verbiage, but cannot confirm this.

They did use reflective buttons for the Interstate shields on ground-mounted guide signs, but I am personally not aware that any slotted-panel signs were made with Interstate shields like they were for US and state route shields.  I think it is quite possible that ground-mounted guide signing using the Interstate shield was not introduced until after Caltrans had started moving toward laminated sign panels and demountable button copy frames.  I am reasonably sure this had happened by 1962, and probably by the late 1950's.

Slotted-panel button copy is an old and expensive technology and the time must have come, probably in the early to mid-1950's, when Caltrans engineers realized it just would not scale well for extensive use on freeways.

(In other news, I have a photo somewhere of a *black* guide sign for I-80/Reno in the Auburn area.  I do not know if it is a violation of AASHO specifications, or it came earlier in 1958 than the manual.   California switched to green signs from black halfway through 1959.)

Could it have been installed while the road was still US 40?  This smells like one of the Roseville Bypass test signs.

Edit:  I rooted through my old Arizona DOT sign design sheets and found some 1962-vintage specs for Interstate shields.  There were variations with and without the state name, but on the shields without the state name, the digits were proportionately a little higher than on the state-name shields but with enough clear blue above the digits to fool your eyes into thinking the state name could fit there.

are those an exact copy of the California shields, with the smaller word INTERSTATE and everything?  I see AZ also was using 30x25 shields as early as 1962 if that spec is to be believed.  (It says 1966 but one of the dates on it is 1962, so I am thinking it is a 1966 re-issue of a 1962 spec.)

I too think it is a 1966 reissue of a 1962 drawing.  I don't think these are exact copies of Caltrans specs, though.  I haven't looked at the dimensioning closely, but I have the impression the Arizona designs have more blue space above the digits than the Caltrans ones.

[agentsteel53]

I know ADOT used Series E Modified on guide sign shields, but I have no information on independent-mount shields (the formal name for "pole mount").  The standard plan sheet I emailed you calls for Series D all the way down the line, but since I have sign design sheets which show Series E Modified in guide-sign shields, I am not sure how far to trust the standard plan sheets in relation to independent-mount shields, which would likely have been fabricated with Scotchlite.

I would imagine the independent-mount shields are just as described, except for a slight difference in font on the word ARIZONA.  Furthermore, they are made of 7/16" wood, just as described in the verbiage of that specification.   

www.aaroads.com/shields/show.php?image=AZ19610403t100400.jpg&search=40

I am pretty sure they must have done, though I haven't personally run across any samples.  I do know that they distributed a sort of catalogue which had details of the various button copy alphabets they sold.  I have run across a copy of it in the Caltrans library in Sacramento, but was not able to get a camera copy of it.

hmm, I'll be in Sacramento in a few days; maybe I can go take a look?

I understand that "Series D Modified" (not really ever one of the official FHWA alphabets) was originally a Stimsonite creation, to accommodate button reflectors.

California loves it, even if in the beginning they did not attach reflectors.  To this day they use it on their pole-mount shields.  Nebraska also uses it a lot.  Then again, California has always liked the bold alphabets.  Here is a US shield in BM.

www.aaroads.com/shields/show.php?image=CA19484661t204660.jpg&search=466

When it was still using button copy, Arizona DOT standardized on Series D Modified for all-uppercase legend on freeway guide signs (cardinal direction words, distance expressions, exit tab legends, etc.) but changed over to Series E or Series E Modified for these applications with the conversion to retroreflective sheeting.

I seem to remember mixed-case Series EM button copy a lot.  Though I am currently looking at a photo of a Series DM "TO" above an I-8 shield on a green sign in Yuma.  (Photo will be up in a few hours; just processing that batch!)  Was there a brief period of Series EM mixed case button copy between all-uppercase DM and retroreflective?

My guess:  this is evidence of Caltrans getting ready to cheat with "mini" shields on overhead guide signs.  The I-10 shield would obviously never have worked as a main guide sign shield (as a general rule, I think only the shields with 1 1/8" borders were intended for this function), but might have been used when shields were desired on multiple lines, or a shield had to be put near a particular downward-pointing arrow to give advance notice of a future split (which is essentially what Richard Ankrom did with his I-5 shield in the downtown LA interchange complex).

That is a 24" shield?  I always thought it was 36, but that just shows how bad I am at sizing up shields that are 15 feet above me.  California also really liked its 21x18 shields on pole-mounted green signs, as well as a one-smaller size (15x12?) as seen here:

www.aaroads.com/shields/show.php?image=CA19700052t100050.jpg&search=5

and here is the 21x18... with a non-standard "5" that California used often.

www.aaroads.com/shields/show.php?image=CA19700152t100152.jpg&search=15

here's a 24x24 example of non-standard fonts.

www.aaroads.com/shields/show.php?image=CA19704051t104050.jpg&search=405

They did use reflective buttons for the Interstate shields on ground-mounted guide signs, but I am personally not aware that any slotted-panel signs were made with Interstate shields like they were for US and state route shields.  I think it is quite possible that ground-mounted guide signing for Interstates was not introduced until after Caltrans had started moving toward laminated sign panels and demountable button copy frames.  I am reasonably sure this had happened by 1962, and probably by the late 1950's.

by slotted-panel, you mean a sign with holes drilled out in the primary surface through which buttons are fitted?  See this one here for an example:

www.aaroads.com/shields/show.php?image=CA19550991t200990.jpg&search=99

the earliest non-porcelain (demountable button copy on metal plate) signs I have seen are a single 1950s-style black, one definitely 1960, and then many examples from 1963 and later.  I think the 1960 was an experiment, since I have seen many porcelain, 1960-63. 

Here is the black sign, which is a single sheet of metal, with button copy letters.  it also says "LA Traffic Comm." on it, leading me to believe that it is a mid-1960s sign, just like other button copy single-sheet signs, but someone just used the wrong color when making it. 

www.aaroads.com/shields/show.php?image=CA19704053t104050.jpg&search=405

I think it was a replacement for a porcelain sign, and then the shield was taken off the higher pole, and this sign was moved up to make room for the green sign.  A real odd duck in any case.

Could it have been installed while the road was still US 40?  This smells like one of the Roseville Bypass test signs.

That is a very likely explanation!  Though it is in Auburn, not Roseville, but perhaps another early bypass?  I uploaded the photo here. 

www.aaroads.com/shields/show.php?image=CA19580803t100800.jpg

Note that that is a 1955-spec (or earlier! 1951?) black sign pair with the extra large capital letters; perhaps they put an I-80 shield over the US-40 when I-80 was designated?

I too think it is a 1966 reissue of a 1962 drawing.  I don't think these are exact copies of Caltrans specs, though.  I haven't looked at the dimensioning closely, but I have the impression the Arizona designs have more blue space above the digits than the Caltrans ones.

possibly ... can you send me the 1961/62 California interstate spec that introduces the pole-mount 30x25 shields?  Also, was this ever a formal spec for three-digit numbers: 24x24 with 6" numbers?

www.aaroads.com/shields/show.php?image=CA19614052t104050.jpg&search=405

[J N Winkler]

I am pretty sure they must have done, though I haven't personally run across any samples.  I do know that they distributed a sort of catalogue which had details of the various button copy alphabets they sold.  I have run across a copy of it in the Caltrans library in Sacramento, but was not able to get a camera copy of it.

hmm, I'll be in Sacramento in a few days; maybe I can go take a look?

It would certainly be worth a try, if you can make it out there during regular office hours (keep in mind that California state employees are on furlough the first three Fridays of every month, as part of Arnie's ongoing budget problems).  Caltrans HQ, where the library is located, is at 1120 N Street.

When it was still using button copy, Arizona DOT standardized on Series D Modified for all-uppercase legend on freeway guide signs (cardinal direction words, distance expressions, exit tab legends, etc.) but changed over to Series E or Series E Modified for these applications with the conversion to retroreflective sheeting.

I seem to remember mixed-case Series EM button copy a lot.  Though I am currently looking at a photo of a Series DM "TO" above an I-8 shield on a green sign in Yuma.  (Photo will be up in a few hours; just processing that batch!)  Was there a brief period of Series EM mixed case button copy between all-uppercase DM and retroreflective?

Not on freeway guide signs--as far as I remember from personal experience (I first drove in Arizona in 1998), and can tell from ADOT sign rehabilitation plans, it was a pretty smooth transition from Series D Modified (all-uppercase) in button copy to Series E/E Modified (also all-uppercase) in retroreflective sheeting.

My guess:  this is evidence of Caltrans getting ready to cheat with "mini" shields on overhead guide signs.  The I-10 shield would obviously never have worked as a main guide sign shield (as a general rule, I think only the shields with 1 1/8" borders were intended for this function), but might have been used when shields were desired on multiple lines, or a shield had to be put near a particular downward-pointing arrow to give advance notice of a future split (which is essentially what Richard Ankrom did with his I-5 shield in the downtown LA interchange complex).

That is a 24" shield?  I always thought it was 36, but that just shows how bad I am at sizing up shields that are 15 feet above me.

I don't know for a fact that it is a 24" shield, though I suspect it is.  My point was that Caltrans probably came up with the 24" size to address the same sort of problem that Ankrom was (without official permission) fixing.

by slotted-panel, you mean a sign with holes drilled out in the primary surface through which buttons are fitted?  See this one here for an example:

www.aaroads.com/shields/show.php?image=CA19550991t200990.jpg&search=99

Yup, that is what I mean by "slotted-panel."  The term is my own invention; I am not sure official terminology exists for this sort of sign (and if it does, it is unlikely to be concise).  I did find one example near the Pasadena Freeway years ago.

Could it have been installed while the road was still US 40?  This smells like one of the Roseville Bypass test signs.

That is a very likely explanation!  Though it is in Auburn, not Roseville, but perhaps another early bypass?  I uploaded the photo here.

I think it is possible the two bypasses were built at the same time.  When I last posted, I thought it was possible Auburn and Roseville were close enough together to be bypassed by the same length of freeway, but a quick look at Google Maps shows that to be a bit of a stretch . . . 

www.aaroads.com/shields/show.php?image=CA19580803t100800.jpg

Note that that is a 1955-spec (or earlier! 1951?) black sign pair with the extra large capital letters; perhaps they put an I-80 shield over the US-40 when I-80 was designated?

I put the date band a bit wider than that--from 1950 (publication of the Forbes/Moskowitz report on all-uppercase versus mixed-case) to early 1958 (when Caltrans decisively abandoned the 3:2 ratio in favor of the 4:3 ratio shown in the Interstate signing manual).  What happened in 1955?

[myosh_tino]

Regarding the California guide sign Interstate shields of 1959, it turns out I exaggerated a little--in fact there were only three standard widths proportionate to height, although there were differences in the allowable sizes, including border widths.  Going through the drawings (which I will email in a moment):

*  I-5:  36" x 36", border width 1 1/8", digit height 16" Series D

*  I-10:  24" x 24", border width 3/4", digit height 12" Series D

*  I-40:  40" x 36", border width 1 1/8", digit height 16" Series D

*  I-480:  48" x 40", border width 1 1/8", digit height 16" Series D

*  I-80:  essentially the same as I-5 shield design (but with two digits)

Then this classic sign on I-15 in Barstow illustrates the differences perfectly.  When I first saw this sign on AARoads, I thought it was kind of strange that the I-15 and I-40 shields were different widths.  I thought this was an optical illusion or some sort of distortion generated by the camera or someone a Caltrans screwed up.

Also, I could have sworn that I saw a gray-scale shield on an advance guide sign for the I-40 exit.  I wasn't sure if my eyes were playing tricks on me and I didn't have time to go back and double check.  I'm headed back to Vegas in late January but if anyone is headed out that way on I-15 sooner, please tell me I was seeing things.