CA 26 on Pomona Freeway

[mrsman]

A recent looking at websites, I came across this website:

https://socalregion.com/east-los-angeles-interchange-signage/

THis shows sign plans with CA-26 being signed on the Santa Monica Fwy and Pomona Fwy.  (Thus emphasizing a point that they really should be viewed as one highway, despite I-10 following the GS Fwy to the SB Fwy.)

My own research indicates that CA-26 once was signed along Olympic and Telegraph from SaMo to Fullerton.  But once US 101 was moved away from Whittier Blvd and onto Telegraph/Santa Ana Freeway, was CA-26 truncated to only exist between Downtown LA and Santa Monica (and thus able to be extended along the Pomona Freeway which west of CA-71 doesn't seem to follow an existing state corridor along surface streets)?

Anybody who can elaborate on some of the history, it will be appreciated.

[cahwyguy]

If you would like, I can drop a note to Michael Ballard, who does that web site, to see what he has to add. We're in touch on email; I don't think he's on this forum anymore.

As I recall, the original plan was to sign Route 26 (Olympic) along the Pomona interchange for a bit (I've got some more details on my website; look at the page for Route 26 -- Michael sent me some stuff for the latest updates). But that changed when the US highway numbering went away.

As I said, if you would like, I'll drop Michael a note.

[sparker]

The original signage of SSR 26 until the Santa Ana Freeway extension as far as Norwalk, was as follows:
(1) LRN 173 from the junction of LRN 60 (Alternate US 101) and LRN 162 (US 66) at the corner of Lincoln and Olympic in Santa Monica east via Olympic Blvd. (with a few right-angle turns south of downtown L.A. in the "garment district"), to LRN 166 at the intersection of Olympic and Telegraph Road in what is now the City of Commerce.  It turned southwest on Telegraph on LRN 166 to Los Nietos Road in Santa Fe Springs, where LRN 166 ended and LRN 171, having come south on Santa Fe Springs Road, turning SE on Los Nietos, continued southeast on Telegraph.  From there it extended to Valley View Ave., where it turned south to Stage Road, which paralleled the Santa Fe RR main line, at which point it turned southeast onto Stage Road.  SSR 26 terminated at SSR 39 in Buena Park at the corner of Grand Avenue (later part of Beach Blvd.) and Stage Road; LRN 171 continued south as SSR 39 to Huntington Beach; northward SSR 39 was part of LRN 62. 

Since the original intent of DOH was to transfer LRN 166 over to the Santa Ana Freeway east of Indiana Ave. in ELA as the freeway was extended south toward Orange County, when it got past Lakewood Blvd. in Downey (the next segment took it as far as Pioneer Blvd. in Norwalk; that opened in early 1957), SSR 26 signage along Telegraph, Valley View, and Stage Road was removed by mid-1957, effectively truncating that route to the Santa Ana Freeway at the Olympic bridge over the freeway. 

At some point between 1957 and about 1960-61 the decision to reroute US 60 off the San Bernardino Freeway west of Pomona onto the proposed Pomona Freeway was made -- likely since the San Bernardino Freeway also was signed at the time as I-10, US 70, and US 99 (an example of the pre-renumbering "sign salad" situation that was partially responsible for the renumbering effort).  I recall seeing, about 1962-63, stand-alone US 60 signs placed adjacent to the standard I-10/US 70/US 99 signage on the San Bernardino Freeway between L.A. and Pomona; if the renumbering had not taken place, those signs would have likely been removed as the Pomona Freeway construction commenced eastward from the ELA interchange.   Thus it's very likely that the SSR 26 signage for the Pomona Freeway was to have been the original field designation for that freeway prior to the US 60 rerouting decision -- but, of course, once US 60 (and 70) were decommissioned within CA post-'64, CA 60 by default became the "successor" designation for the Pomona Freeway.  I was attending UCR during the late '60's and recall that US 60 signage was removed from D7 territory (L.A. County) and replaced with green CA 60 shields by February 1968; within a year all of US 60 west of Beaumont (in D8) was resigned as CA 60.  US 60 shields continued east through Indio and toward Blythe until all sections of I-10 (with the exception of the Indio bypass, which was the last piece of that particular puzzle) were completed. 

[mrsman]

If you would like, I can drop a note to Michael Ballard, who does that web site, to see what he has to add. We're in touch on email; I don't think he's on this forum anymore.

As I recall, the original plan was to sign Route 26 (Olympic) along the Pomona interchange for a bit (I've got some more details on my website; look at the page for Route 26 -- Michael sent me some stuff for the latest updates). But that changed when the US highway numbering went away.

As I said, if you would like, I'll drop Michael a note.

Sure that would be great.  Any explanation is appreciated.

[mrsman]

The original signage of SSR 26 until the Santa Ana Freeway extension as far as Norwalk, was as follows:
(1) LRN 173 from the junction of LRN 60 (Alternate US 101) and LRN 162 (US 66) at the corner of Lincoln and Olympic in Santa Monica east via Olympic Blvd. (with a few right-angle turns south of downtown L.A. in the "garment district"), to LRN 166 at the intersection of Olympic and Telegraph Road in what is now the City of Commerce.  It turned southwest on Telegraph on LRN 166 to Los Nietos Road in Santa Fe Springs, where LRN 166 ended and LRN 171, having come south on Santa Fe Springs Road, turning SE on Los Nietos, continued southeast on Telegraph.  From there it extended to Valley View Ave., where it turned south to Stage Road, which paralleled the Santa Fe RR main line, at which point it turned southeast onto Stage Road.  SSR 26 terminated at SSR 39 in Buena Park at the corner of Grand Avenue (later part of Beach Blvd.) and Stage Road; LRN 171 continued south as SSR 39 to Huntington Beach; northward SSR 39 was part of LRN 62. 

Since the original intent of DOH was to transfer LRN 166 over to the Santa Ana Freeway east of Indiana Ave. in ELA as the freeway was extended south toward Orange County, when it got past Lakewood Blvd. in Downey (the next segment took it as far as Pioneer Blvd. in Norwalk; that opened in early 1957), SSR 26 signage along Telegraph, Valley View, and Stage Road was removed by mid-1957, effectively truncating that route to the Santa Ana Freeway at the Olympic bridge over the freeway. 

At some point between 1957 and about 1960-61 the decision to reroute US 60 off the San Bernardino Freeway west of Pomona onto the proposed Pomona Freeway was made -- likely since the San Bernardino Freeway also was signed at the time as I-10, US 70, and US 99 (an example of the pre-renumbering "sign salad" situation that was partially responsible for the renumbering effort).  I recall seeing, about 1962-63, stand-alone US 60 signs placed adjacent to the standard I-10/US 70/US 99 signage on the San Bernardino Freeway between L.A. and Pomona; if the renumbering had not taken place, those signs would have likely been removed as the Pomona Freeway construction commenced eastward from the ELA interchange.   Thus it's very likely that the SSR 26 signage for the Pomona Freeway was to have been the original field designation for that freeway prior to the US 60 rerouting decision -- but, of course, once US 60 (and 70) were decommissioned within CA post-'64, CA 60 by default became the "successor" designation for the Pomona Freeway.  I was attending UCR during the late '60's and recall that US 60 signage was removed from D7 territory (L.A. County) and replaced with green CA 60 shields by February 1968; within a year all of US 60 west of Beaumont (in D8) was resigned as CA 60.  US 60 shields continued east through Indio and toward Blythe until all sections of I-10 (with the exception of the Indio bypass, which was the last piece of that particular puzzle) were completed.

This all makes perfect sense.  Construction of the Santa Ana Freeway (and thus removal of state highway status on Telegraph-Los Nietos-Stage) truncated CA-26 at the same time as plans for the Pomona Freeway came aboard, so it was only natural to at least propose CA-26 as the natural extension from the Olympic Freeway onto the Pomona Freeway.  This though was changed once it was decided to remove US 60 from the San Bernardino Freeway and to place it along the Pomona Freeway instead.  And of course with 1964 an entire cleanup of all the signage for simplicity.

While I appreciate the efforts at simplicity of routing that the 1964 renumbering achieved, I do regret that US 99 and US 60 were turned into state routes.  The US highway in CA signifies very important roads, because there are so few of them.  US 99 signed north of Wheeler Ridge and a US 60 signed alongside the full Pomona Fwy (and co-signed on I-10 from Beaumont to Arizona) would allow drivers to recognize that those routes are part of national corridors and not simply local connectors.

I still feel strongly that signage has a lot to do with traffic patterns.  There are definitely a lot of people who drive from the Santa Monica - GS - San Bernardino freeways, simply to follow I-10.  Drivers from Santa Monica who want to go east to Palm Springs and beyond would be better off just making the connection from Santa Monica to the Pomona Freeway instead, but they don't because they are following the numbers, thereby unnecessarily clogging up the East LA interchange.  (And even for those drivers that want the San Bernardino Freeway, they are probably better off making the connection from 60 to 10 utilizing the 710, 605, or the 57 rather than the Golden State Fwy - the further east, the better.) 

Signage of both the Santa Monica and the Pomona with the same number signifies that they are one corridor (as was briefly contemplated with CA-26).  Alternatively, signage of the Pomona with a US highway number signifies a route of national importance (that reaches all the way to the Atlantic Coast in Virginia Beach, VA).  Either signage choice would probably mean lower traffic counts making the Santa Monica-GoldenState-San Bernardino freeway transition.

[sparker]

^^^^^^^^^^
The existence of the winding 4-lane expressway section of CA 60 through the "badlands" between Moreno Valley and Beaumont was and is likely the reason for DOH and later Caltrans preference for I-10 as the main corridor east of greater L.A. rather than CA 60.  That was bolstered by the expansion of I-10 to 3+3 between Redlands and Beaumont in the mid-60's (although they didn't get rid of the substandard-clearance overpasses on that route until the '90's).  If driving the roller-coaster through the badlands while dodging truck traffic doesn't faze a driver, then CA 60 will definitely save some mileage heading east from O.C. and the southern reaches of L.A. County (personally, if I were taking a carload of folks in that direction, I'd head for I-10!).

The decision to jettison US 99 from CA was a done deal when DOH was informed that OR was going to do the same thing once I-5 was substantially completed there.  Part of the unremarked aspects of the '64 renumbering was that all the remaining US highways crossed the state line; not having a signed US 99 in Oregon would have meant that under the new "one route one number" edict only a Wheeler Ridge-Red Bluff fully in-state US 99 would have existed; and the then-DOH management elected not to maintain US signage on such facilities.  Of course, this led to the awkward signage situation from mid-1966, when US 99 signage from Los Angeles to Sacramento came down and was replaced by green CA 99 shields, of US 101 being the sole US and/or Interstate highway (US 395, which exited into NV, notwithstanding) connecting southern and northern CA until I-5 was completed as far north as Stockton in 1972 (and continued on as "Temporary I-5" over CA 99 from there to Sacramento until 1981).   But since DOH had gotten rid of US 99E signage and replaced it with CA 99 (and CA 65 further south) shields back in 1964-65, US 99 was considered at the time of signage replacement to be isolated from the remnants of that route further north and thus functionally obsolete; they wanted to make the full signage of CA 99 in the Valley a fait accompli to avoid navigational issues.   Retention of historically significant routes has never been either the DOH's or Caltrans' strong suit!       

[Exit58]

With the advent of GPS and it being in every phone the purpose of having just one main route number in/out of the area is a rather innocuous issue. Of course, the flip-side of that is what does it matter if a highway has just one number. Either way I'm still a fan of extending US 60 on AZ 72/95/CA 62 through Parker and 29 Palms, and making that short overlap on I-10 to Beaumont to reclaim CA 60. I doubt either state cares enough to do it, however it honestly would have been nice to know when I was traveling that that route existed before I ran in to traffic at Chiraco.

Anyway, this again made me question the 60/57 overlap. Technically the 57 has the route gap when it should be 60 according to the highway hierarchy. I always thought this was because the freeway was planned as US 60, which would have precedent over a State Route. I then thought that maybe they were considering keeping US 60 post-1964 until I looked further west and realized that the US 60-395 Overlap was assigned to Route 395 and not Route 60. Both being US highways, it should have been 395 with the gap, not 60. So what's the purpose of the 60 being the preferred route over 57? Just an oversight perhaps?

I also have no doubt the original plan would have been to have SSR 26 on the Pomona Fwy to the interchange with modern SR 71, where US 60 would have taken over from the north. It makes too much sense.

[cahwyguy]

First, don't expect sense from Caltrans or the Division of Highways.

I've found no evidence that there were ever plans to sign US 60 on what became the Pomona Freeway W of the jct with Route 71. All the maps and evidence I can find, and all the state highway maps, show US 60 along LRN 26 (current I-10) to around Holt, then cutting down along the present Route 71 freeway (Route 71 at the time was on Garvey) to 5th (and later, the freeway), and then continuing E. State Sign Route 60 was not signed until the Pomona Freeway was completed.

I've found no evidence of Sign Route 26 being extended to the 71, or even outside of the East LA Interchange. As I note on my pages: "By the time the 1938 state highway map was printed, LRN 173 (defined in 1933), the route originally signed as Route 6 was resigned as Route 26. The original signed Route 6 ran from Santa Monica to Jct. Route 39 in Fullerton along roughly Olympic and Whittier. In Los Angeles, it ran between US101A (Lincoln Blvd) and US101 along 10th Street, later renamed Olympic Blvd (in 1939, the route ran along Pico between Lincoln and Robertson). Evidently, the original plan was to call this Route 6, but that went away when US 6 was assigned to a different route. It used the McClure Tunnel now used for I-10. Olympic Boulevard was built (widened and realigned) in two stages. By 1938, major improvements were completed. The jog at Figueroa Street was eliminated. Near Alvarado Street, Hoover Street and Arlington Avenue, Olympic Boulevard was realigned away from 10th Street to provide continuity. Westerly of Lucerne Boulevard, Country Club Drive was renamed Olympic Boulevard, widened throughout and extended through the 20th Century Fox movie studio property. Further improvements were disrupted by World War II. In 1948, the final links of Olympic Boulevard were constructed between Crenshaw Boulevard and Lucerne Boulevard and between Centinela Avenue and Lincoln Boulevard. The latter project was built as a landscaped divided parkway with no driveways through the City of Santa Monica. Before the construction of the freeway in downtown LA, the route continued along Olympic Blvd and 9th St. to Atlantic Blvd (Route 15; LRN 167). A 1942 map shows that Route 26 was cosigned with Bypass US 101 from approximately the Olympic/Telegraph junction to Route 19. A 1948 map shows the route running along Olympic, 9th St, Anaheim, Telegraph, Los Nietos, Whittier Road, La Mirada Road, and La Habra Road, terminating at the intersection of Manchester Blvd (then Bypass US 101) and La Habra Road in Buena Park. It was later replaced by I-10, the Santa Monica Freeway, but early plans show this as the Olympic Freeway. The signage for Route 26 may have been down by 1959."

Daniel

[Exit58]

First, don't expect sense from Caltrans or the Division of Highways.

I've found no evidence that there were ever plans to sign US 60 on what became the Pomona Freeway W of the jct with Route 71. All the maps and evidence I can find, and all the state highway maps, show US 60 along LRN 26 (current I-10) to around Holt, then cutting down along the present Route 71 freeway (Route 71 at the time was on Garvey) to 5th (and later, the freeway), and then continuing E. State Sign Route 60 was not signed until the Pomona Freeway was completed.

I've found no evidence of Sign Route 26 being extended to the 71, or even outside of the East LA Interchange. As I note on my pages: "By the time the 1938 state highway map was printed, LRN 173 (defined in 1933), the route originally signed as Route 6 was resigned as Route 26. The original signed Route 6 ran from Santa Monica to Jct. Route 39 in Fullerton along roughly Olympic and Whittier. In Los Angeles, it ran between US101A (Lincoln Blvd) and US101 along 10th Street, later renamed Olympic Blvd (in 1939, the route ran along Pico between Lincoln and Robertson). Evidently, the original plan was to call this Route 6, but that went away when US 6 was assigned to a different route. It used the McClure Tunnel now used for I-10. Olympic Boulevard was built (widened and realigned) in two stages. By 1938, major improvements were completed. The jog at Figueroa Street was eliminated. Near Alvarado Street, Hoover Street and Arlington Avenue, Olympic Boulevard was realigned away from 10th Street to provide continuity. Westerly of Lucerne Boulevard, Country Club Drive was renamed Olympic Boulevard, widened throughout and extended through the 20th Century Fox movie studio property. Further improvements were disrupted by World War II. In 1948, the final links of Olympic Boulevard were constructed between Crenshaw Boulevard and Lucerne Boulevard and between Centinela Avenue and Lincoln Boulevard. The latter project was built as a landscaped divided parkway with no driveways through the City of Santa Monica. Before the construction of the freeway in downtown LA, the route continued along Olympic Blvd and 9th St. to Atlantic Blvd (Route 15; LRN 167). A 1942 map shows that Route 26 was cosigned with Bypass US 101 from approximately the Olympic/Telegraph junction to Route 19. A 1948 map shows the route running along Olympic, 9th St, Anaheim, Telegraph, Los Nietos, Whittier Road, La Mirada Road, and La Habra Road, terminating at the intersection of Manchester Blvd (then Bypass US 101) and La Habra Road in Buena Park. It was later replaced by I-10, the Santa Monica Freeway, but early plans show this as the Olympic Freeway. The signage for Route 26 may have been down by 1959."

Daniel

Well to be honest we all thought it was impossible for SSR 30 to be signed in Pasadena on old US 66 until we found maps showing it as such. I think these signage plans Micheal uncovered lend credence to an extension of SSR 26 past the East LA interchange. It was likely not signed very far or for very long considering how it was all still being constructed, but I'd put money on that being the plan. Of course no one will ever know for certain, unless more info comes out of Caltrans. I'd be curious to see the sign plans - if there were any at that time - for the Diamond Bar Overlap.

Now that I think about it, was there ever a full-fledge freeway (more than, say, SR 259) that was planned without having a planned sign route on it? I can't think of one of the top of my head but it is also late lol.

[sparker]

^^^^^^^^^^^^
With all the changes to the signed highway system in the years leading up to the 1964 massive renumbering, including the never-actually-deployed alignment change of US 6 in the San Fernando Valley and onto a multiplex with US 101 (notated by Gousha in 1963) and the downgrading of US 60 signage on the newly-signed I-10/San Bernardino Freeway west of Pomona, it's likely the DOH held actual signage for freeways planned for near-term construction, such as the Pomona (the alignment of which was adopted in the late '50's with construction starting in late '64, and with the initial section from the ELA interchange to I-605 opening in the summer of 1967) close to the vest until the renumbering effort -- which itself had been in the works for years and never a "spur-of-the-moment" project.   Committing to the signing of a route that in short order would be changed anyway was never a consideration.   In the L.A. area a few  freeways' signage was "usurped" during the first three months of 1964, including US 66 along the then-Pasadena Freeway, replaced initially by CA 11 (moved a few blocks over from Figueroa), CA 91 over previous SSR 14 on the Riverside Freeway through Fullerton and east Anaheim, CA 7 (now I-710) replacing SSR 15 on the Long Beach Freeway, and US 6 disappearing altogether, replaced by, again, CA 11 (which had always had co-signage) on the Harbor Freeway and, in its only other independent segment, CA 14 from Sylmar out toward Palmdale and Mojave.   Besides the removal of US highway shields from Interstate facilities, the actual numbering changes were decidedly limited in scope; a lot of SSR-signed freeways were "re-upped" as new identically-numbered CA facilities, complete with green shields.  But the renumbering served another purpose -- allowing more rational numbers to be applied to certain facilities, such as CA 60 over the Pomona Freeway, itself a southern "relief route" for the ever-congested I-10 a few miles to the north.  D7's removal of all US 60 signage from L.A. County occurred simultaneously with the opening of the Pomona Freeway/CA 60 east of I-605 to Fullerton Road in Rowland Heights in February 1968; from there CA 60 was signed south on Fullerton to Colima Road, east on Colima to Brea Canyon Road, and north and east on Brea Canyon to the intersection of CA 71 and 5th Street in Pomona; it then took over US 60's former route east on 5th Street to the San Bernardino county line (where D8 commenced).  That alignment was gradually replaced from west to east as the Pomona Freeway was completed farther east.     

[mrsman]

While many of us with the hindsight of 55 years can quibble about certain aspects of the 1964 renumbering (I personally would have loved to see US 60, US 99 north of Wheeler Ridge, and US 66 maintained in some form), we can all appreciate that it was the right thing to do.  It simplified the signage at many of the up and coming freeway interchanges.  At the 4-level you had US 101 on the E-W strand and CA-11 on the N-S strand, instead of the jumble of US routes that migrated from one strand to the other.  Ditto at San Bernardino split and the current I-10/I-215 interchange in Colton.  It had the effect of making unified corridors.  One 60 freeway corridor from Downtown LA to Beaumont as opposed to a mix of CA-26 and US 60.  One 91 freeway corridor from Riverside to (planned) Redondo Beach instead of a mix of US 91, CA 18 and CA 14.  The simplification was absolutely necessary, despite its effect of wiping out historical number routings.

[cahwyguy]

Well to be honest we all thought it was impossible for SSR 30 to be signed in Pasadena on old US 66 until we found maps showing it as such. I think these signage plans Micheal uncovered lend credence to an extension of SSR 26 past the East LA interchange. It was likely not signed very far or for very long considering how it was all still being constructed, but I'd put money on that being the plan. Of course no one will ever know for certain, unless more info comes out of Caltrans. I'd be curious to see the sign plans - if there were any at that time - for the Diamond Bar Overlap.

Being signed at that interchange does not mean it was signed out to the 71. More likely, it was signed there to direct folks travelling on SSR 26 (which, at the time, was the Olympic/Santa Monica Freeway) to the continuation, which would have followed the 5/101 through the interchange and S to Route 39, not E to the 71. Remember the definition of SSR 26: "Santa Monica to Jct. Route 39 in Fullerton". So this was just directing travelers to where Whittier or Olympic would exit. That makes much more sense than an extension of Sign Route 26 to Route 71.

[ClassicHasClass]

Well to be honest we all thought it was impossible for SSR 30 to be signed in Pasadena on old US 66 until we found maps showing it as such.

Got a link handy?

[NE2]

Being signed at that interchange does not mean it was signed out to the 71. More likely, it was signed there to direct folks travelling on SSR 26 (which, at the time, was the Olympic/Santa Monica Freeway) to the continuation, which would have followed the 5/101 through the interchange and S to Route 39, not E to the 71. Remember the definition of SSR 26: "Santa Monica to Jct. Route 39 in Fullerton". So this was just directing travelers to where Whittier or Olympic would exit. That makes much more sense than an extension of Sign Route 26 to Route 71.

That was the 1934 definition of SSR 6, but it definitely changed over the years. The 1963 official has several US 101 shields between East LA and Buena Park, with no SR 26 shields anywhere along that road. 1951 is the last to show any SR 26 shields east of Downey Road, with LR 171 being deleted north of LR 62 later that year.

[cahwyguy]

Being signed at that interchange does not mean it was signed out to the 71. More likely, it was signed there to direct folks travelling on SSR 26 (which, at the time, was the Olympic/Santa Monica Freeway) to the continuation, which would have followed the 5/101 through the interchange and S to Route 39, not E to the 71. Remember the definition of SSR 26: "Santa Monica to Jct. Route 39 in Fullerton". So this was just directing travelers to where Whittier or Olympic would exit. That makes much more sense than an extension of Sign Route 26 to Route 71.

That was the 1934 definition of SSR 6, but it definitely changed over the years. The 1963 official has several US 101 shields between East LA and Buena Park, with no SR 26 shields anywhere along that road. 1951 is the last to show any SR 26 shields east of Downey Road, with LR 171 being deleted north of LR 62 later that year.

But the key point is that none of the definitions had it signed out along the future Pomona Freeway to the 71. At best, it would have continued down US 101 to Buena Park, and then diverged from the US 101 mainline. At best. That's not the new Pomona Freeway routing, so assuming that signage of SSR 26 at the East LA interchange is for the Pomona Freeway (especially as this is based on early sign drawings) is likely a mistake.

[NE2]

But the key point is that none of the definitions had it signed out along the future Pomona Freeway to the 71.

But we don't have access to most of these definitions.

[sparker]

Being signed at that interchange does not mean it was signed out to the 71. More likely, it was signed there to direct folks travelling on SSR 26 (which, at the time, was the Olympic/Santa Monica Freeway) to the continuation, which would have followed the 5/101 through the interchange and S to Route 39, not E to the 71. Remember the definition of SSR 26: "Santa Monica to Jct. Route 39 in Fullerton". So this was just directing travelers to where Whittier or Olympic would exit. That makes much more sense than an extension of Sign Route 26 to Route 71.

That was the 1934 definition of SSR 6, but it definitely changed over the years. The 1963 official has several US 101 shields between East LA and Buena Park, with no SR 26 shields anywhere along that road. 1951 is the last to show any SR 26 shields east of Downey Road, with LR 171 being deleted north of LR 62 later that year.

But the key point is that none of the definitions had it signed out along the future Pomona Freeway to the 71. At best, it would have continued down US 101 to Buena Park, and then diverged from the US 101 mainline. At best. That's not the new Pomona Freeway routing, so assuming that signage of SSR 26 at the East LA interchange is for the Pomona Freeway (especially as this is based on early sign drawings) is likely a mistake.

If today's westernmost section of I-10 on the Santa Monica Freeway had not been included in the Interstate System (likely via an addition in the famous/infamous "Yellow Book") and I-10 were to end at I-5 instead, the Santa Monica Freeway would have likely assumed SSR 26 signage as a functional replacement for Olympic Blvd.  In that case -- and also speculating that the decision to remove US 60 from the San Bernardino Freeway west of Pomona had yet to occur, there's a possibility that initial signage plans for the Pomona Freeway may well have been a continuation of the SSR 26 Santa Monica Freeway signage.  It all depends upon (a) when DOH configured the ELA interchange (the "gully" holding the transition from current WB 60 to WB 10 was there by the mid-50's, along with the corresponding overpass along then-US 101, so it's likely the interchange was designed well before Interstate days); and (b) exactly when I-10 was extended from downtown to the coast.  Preliminary signage outlines pre-Yellow Book could have cited SSR 26 as the planned field designation for the freeway, which would have been LRN 172.  Of course, ushering in the Interstate era would have altered things considerably; with the post-'57 Santa Monica Freeway now designated as I-10, it's not unlikely that the SSR 26 designation would have been retained for the Pomona Freeway east of the ELA at least on signage plans before the '64 renumbering; the relinquishment of the section of SSR 26 east of the City of Commerce functionally "freeing up" the number for that purpose.  But it appears that signage bets were indeed hedged; IIRC, official state highway maps from 1959 on that showed the Pomona Freeway alignment only cited LRN 172 up to 1964; no SSR was shown for that facility until CA 60 was designated in '64 and posted three years later.   If anyone has or can obtain a copy of an official DOH map from '59 through '63, the lack of SSR designation for the LRN 172/Pomona freeway can be verified.

[NE2]

If today's westernmost section of I-10 on the Santa Monica Freeway had not been included in the Interstate System (likely via an addition in the famous/infamous "Yellow Book") and I-10 were to end at I-5 instead,

Santa Monica-LA was part of the 1947 plan (though it's possible they hadn't decided yet on Santa Monica Freeway vs. Beverly Hills Freeway).

[cahwyguy]

And remember that I focus on facts, not speculation or hypothetical. All we have is a proposed sign at the East LA interchange, which factually says nothing about the route further east. With no other data to the contrary, I don't think we can make assumptions about where SSR 26 would have continued (at least not, nothing worthy of putting on my pages).

[sparker]

And remember that I focus on facts, not speculation or hypothetical. All we have is a proposed sign at the East LA interchange, which factually says nothing about the route further east. With no other data to the contrary, I don't think we can make assumptions about where SSR 26 would have continued (at least not, nothing worthy of putting on my pages).

Having spent more time in the Caltrans basement library (in their Sacramento O Street HQ) that I care to recall while working on academic projects, a thorough rummaging there might well yield more detailed information about what DOH actually proposed -- at least within internal documents -- for various matters, including the one at issue here.  I'll suggest a first step -- thumbing through back issues (or the corresponding files) of CH&PW to determine when the various segments of the Pomona Freeway alignment (both the LRN 172 and LRN 19 sections) were formally adopted.  If, as NE2 states, the inclusion of Santa Monica to Los Angeles in the Interstate System was done as early as 1947, that renders any attempt to analyze the limited information on hand to date as inconclusive.  Given the lack of SSR designation on the adopted Pomona alignment -- at least on official DOH maps prior to the '64 renumbering -- it's likely that any projected SSR designation was held in abeyance during that period and, of course, rendered moot post-'64.  If a SSR 26 shield was appended to a proposed BGS on or approaching the Pomona Freeway, it likely was placed there by a graphics person in D7 who simply wished to show where a shield would be located on the completed sign.  BTW, the speculation of I-10 on the Beverly Hills rather than the Santa Monica/Olympic freeway alignment is most interesting, since the earlier Yellow Book editions were deliberately vague regarding exact locations of alignments, preferring to specify general location.     

[mrsman]

And remember that I focus on facts, not speculation or hypothetical. All we have is a proposed sign at the East LA interchange, which factually says nothing about the route further east. With no other data to the contrary, I don't think we can make assumptions about where SSR 26 would have continued (at least not, nothing worthy of putting on my pages).

Having spent more time in the Caltrans basement library (in their Sacramento O Street HQ) that I care to recall while working on academic projects, a thorough rummaging there might well yield more detailed information about what DOH actually proposed -- at least within internal documents -- for various matters, including the one at issue here.  I'll suggest a first step -- thumbing through back issues (or the corresponding files) of CH&PW to determine when the various segments of the Pomona Freeway alignment (both the LRN 172 and LRN 19 sections) were formally adopted.  If, as NE2 states, the inclusion of Santa Monica to Los Angeles in the Interstate System was done as early as 1947, that renders any attempt to analyze the limited information on hand to date as inconclusive.  Given the lack of SSR designation on the adopted Pomona alignment -- at least on official DOH maps prior to the '64 renumbering -- it's likely that any projected SSR designation was held in abeyance during that period and, of course, rendered moot post-'64.  If a SSR 26 shield was appended to a proposed BGS on or approaching the Pomona Freeway, it likely was placed there by a graphics person in D7 who simply wished to show where a shield would be located on the completed sign.  BTW, the speculation of I-10 on the Beverly Hills rather than the Santa Monica/Olympic freeway alignment is most interesting, since the earlier Yellow Book editions were deliberately vague regarding exact locations of alignments, preferring to specify general location.     

Even if there were a published map of the National System of Interstate Highways back in 1947, I doubt that all of the details like numbering was formulated before passage of the 1956 Act that allowed the Interstates to be funded. 

[sparker]

And remember that I focus on facts, not speculation or hypothetical. All we have is a proposed sign at the East LA interchange, which factually says nothing about the route further east. With no other data to the contrary, I don't think we can make assumptions about where SSR 26 would have continued (at least not, nothing worthy of putting on my pages).

Having spent more time in the Caltrans basement library (in their Sacramento O Street HQ) that I care to recall while working on academic projects, a thorough rummaging there might well yield more detailed information about what DOH actually proposed -- at least within internal documents -- for various matters, including the one at issue here.  I'll suggest a first step -- thumbing through back issues (or the corresponding files) of CH&PW to determine when the various segments of the Pomona Freeway alignment (both the LRN 172 and LRN 19 sections) were formally adopted.  If, as NE2 states, the inclusion of Santa Monica to Los Angeles in the Interstate System was done as early as 1947, that renders any attempt to analyze the limited information on hand to date as inconclusive.  Given the lack of SSR designation on the adopted Pomona alignment -- at least on official DOH maps prior to the '64 renumbering -- it's likely that any projected SSR designation was held in abeyance during that period and, of course, rendered moot post-'64.  If a SSR 26 shield was appended to a proposed BGS on or approaching the Pomona Freeway, it likely was placed there by a graphics person in D7 who simply wished to show where a shield would be located on the completed sign.  BTW, the speculation of I-10 on the Beverly Hills rather than the Santa Monica/Olympic freeway alignment is most interesting, since the earlier Yellow Book editions were deliberately vague regarding exact locations of alignments, preferring to specify general location.     

Even if there were a published map of the National System of Interstate Highways back in 1947, I doubt that all of the details like numbering was formulated before passage of the 1956 Act that allowed the Interstates to be funded. 

Absolutely correct.  While the basic trunk route numbering format had been formulated early in the process, the format to be assigned to auxiliary routes wasn't finalized until about 1958, when the current system was formulated.   Before that, CA's DOT was assigning numbers almost on a random basis to connectors and loops (possibly a precursor of their '64 methodology -- or lack thereof!?).