1934 California route grid/numbering conventions

[TheStranger]

An outgrowth of the sub-discussion in the I-405/San Diego Freeway thread, where this came up due to the placement of 1934-1958 Route 7 in the Los Angeles metro area relative to 1934-1936 Route 3 and 1934-1981 Route 11!
https://www.aaroads.com/forum/index.php?topic=24958.msg2415285#new

Kinda interesting to compare this to some of the later mini-clustering that occurred in the 1964 renumbering (which did seek to retain as many of the 1934 routes as possible).

All of this is based off of what we had already known about California's numbering in 1934 (each region would have routes assigned in a block of every-four-numbers,

Patterns identified so far, all using the 1934 routes as reference points.  Asterisk marks that some or all of the 1934 route number assignment still exists today.

Southern California:

Sequence 1, west to east (Los Angeles County)
3 (Pacific Coast Highway)
7 (Hawthorne Boulevard, Sepulveda Boulevard, Sierra Highway)
11 (Figueroa Street)
15 (Atlantic Avenue)
*19 (Lakewood Boulevard/Rosemead Boulevard)

Sequence 2, west to east (Ventura County/Los Angeles County)
*23 (Decker Road)
*27 (Topanga Canyon Boulevard)

Sequence 3, west to east (Los Angeles County/Orange County)
35 (Telephone Road)
*39 (Azusa Avenue/Beach Boulevard)

Sequence 4, north to south (Los Angeles County/Orange County)
*2 (Santa Monica Boulevard/Angeles Crest Highway)
6 (Olympic Boulevard)
10 (Firestone Boulevard/Manchester Avenue)
14 (Artesia Boulevard)
*18 (Lincoln Avenue) (NOTE: the portion of Route 18 that exists today, though original to the 1934 route definition, does not include the segment that falls in the Los Angeles/Orange grid anymore)
*22 (Garden Grove Boulevard)
26 (Bolsa Avenue?)

Sequence 5, semi-organized cluster near San Diego
Route 67 is not an original 1934 route but fits this pattern.
*71 (Kearny Villa Road/Escondido Boulevard) (existing 71 however is not the portion that is part of this original grid)
Route 75 (Silver Strand) is also not an original 1934 route, but fits.
*79 (Alpine to Aguanga corridor)


Sequence 6, San Diego/Imperial
*94 (Campo Road)
*98 (Birch Street, Calexico)

Sequence 7, Orange/San Diego coast
*74 (Ortega Canyon Highway)
*78 (San Pasqual Valley Road)

Sequence 8, centered around San Fernando Valley.  Every eight digits rather than every 4
*118 (Los Angeles Avenue)
*126 (Telegraph Road)
*134 (Colorado Street)


Northern California

Sequence 1, west to east (Bay Area)
*1 (Cabrillo Highway, 19th Avenue, etc.)
5 (Skyline Boulevard) [modern Route 35]
*9 (Big Basin Way, Sunnyvale-Saratoga Road, Alviso Road) (NOTE: the portion that falls correctly in the 1934 grid, which corresponds to today's Route 85 and 237, has not been part of Route 9 since the 1964 renumbering))
13 (Oakland Road) - renumbered shortly after to 17; the next new route in the region followed the grid pattern, 21 along the Pacheco Boulevard corridor.

25, 29, 33, 37 all are in NorCal but not tightly organized to a grid.

Sequence 2, south to north (Central Valley)
*4 (John Muir Highway/Charter Way)
8 (road from Stockton to Valley Springs, incorporating part of Fremont Street in Stockton) [modern Route 26 and Route 88]
*12 (Kettleman Lane)
*16 (included Main Street in Woodland, Sacramento Avenue in West Sacramento, Capitol Mall/Capitol Avenue/Folsom Boulevard in Sacramento)
*20 (5th Street in Marysville originally?)
*24 (Feather River Canyon route) - note that the portion of 24 that exists today is a small sliver of the original route, and the segment that fell within this Central Valley grid has been renumbered first as Alternate US 40 and then as modern Route 70.
(Unclear how well 28 was ever signed and the route never entered the Valley)

Sequence 2A, south to north
*32 (Deer Creek Highway, Chico)
*36 (Antelope Boulevard, Red Bluff)
(40 skipped due to US 40)
*44 through Redding - while the 1934 routing became US (now state route) 299, the 1935-present routing (which was 1934-1935 Route 440, an early child route) extended right off of this and fits in the grid.

Central Valley

Sequence 1, north to south - note that there is overlap with the 4 to 44 sequence above. 
*104 (Twin Cities Road)
*108 (Sonora Pass)

Sequence 2, north to south - the number spacing increases significantly at this point, every 12 or so?
*120 (Yosemite Avenue)
*132 (Maze Boulevard)
*140 (Central Yosemite Highway)
*152 (Pacheco Boulevard)

Sequence 3, north to south, centered around Fresno
*168 (Shaw Avenue/Tollhouse Road)
*180 (Kings Canyon Road)

Sequence 4, south to north, starting in Ventura, digit gap is not completely even.
(NOTE: Could 138 be part of this pattern too?  Not sure.)
*150 (Ojai Road)
*166 (Maricopa Highway)
*178 (Kern Canyon Road)
*190 (Avenue 144/Poplar Avenue)
*198 (Hanford to Visalia corridor)

Sequence 5
*41 (Blackstone Avenue)
*49 (Golden Chain Highway) - 49 itself derived its number from the 1849 gold rush.

There are several other routes which were created in 1934 but did not conform to the grid sequence and were not child routes like 440/740:
*55
*65
*89
95
*111
195

[Max Rockatansky]

Never occurred to me the 150 and 166 were part of the same sequence with 178, 190 and 198 until you pointed it out.  I'd argue that 41, 49, 55, 65 and 89 more or less fall into a pattern of ascending eastward (25 and 33 tend to support this being a thing).   Too bad the original design has gotten so mucked up over the years. 

[TheStranger]

Never occurred to me the 150 and 166 were part of the same sequence with 178, 190 and 198 until you pointed it out.  I'd argue that 41, 49, 55, 65 and 89 more or less fall into a pattern of ascending eastward (25 and 33 tend to support this being a thing).   Too bad the original design has gotten so mucked up over the years. 

Hmm, would 25/33/41/49 count as one of the patterns?  They all seem to be extended north-south corridors roughly in the central part of NorCal.

It's interesting how the every-four sequence in the lower numbers really wasn't maintained later in the grid, which isn't quite as understandable thinking of how many 2 digit numbers remained unused from 1934 to 1964: 31, 47, 51, 56, 57, 58, 61, 62, 64, 68, 69, 72, 73, 77, 81, 82, 85, 86, 87, 90, 92, 93.

[Max Rockatansky]

Never occurred to me the 150 and 166 were part of the same sequence with 178, 190 and 198 until you pointed it out.  I'd argue that 41, 49, 55, 65 and 89 more or less fall into a pattern of ascending eastward (25 and 33 tend to support this being a thing).   Too bad the original design has gotten so mucked up over the years. 

Hmm, would 25/33/41/49 count as one of the patterns?  They all seem to be extended north-south corridors roughly in the central part of NorCal.

It's interesting how the every-four sequence in the lower numbers really wasn't maintained later in the grid, which isn't quite as understandable thinking of how many 2 digit numbers remained unused from 1934 to 1964: 31, 47, 51, 56, 57, 58, 61, 62, 64, 68, 69, 72, 73, 77, 81, 82, 85, 86, 87, 90, 92, 93.

I certainly think that is an intentional pattern, especially when you consider how the other sequences follow something similar.  Really there was a real missed opportunity in adding new route numbers and the 1964 to maintain the grid continuity the original 1934 design had.  The US Route extensions and additions didn't really take much away from the 1934 grid and were often on unnumbered State Highways or multiplexed those that were established (example; US 6 and CA 11).   Other states ended up doing their renumberings in patterns like Nevada and Washington. 

[TheStranger]

I certainly think that is an intentional pattern, especially when you consider how the other sequences follow something similar.  Really there was a real missed opportunity in adding new route numbers and the 1964 to maintain the grid continuity the original 1934 design had.  The US Route extensions and additions didn't really take much away from the 1934 grid and were often on unnumbered State Highways or multiplexed those that were established (example; US 6 and CA 11).   Other states ended up doing their renumberings in patterns like Nevada and Washington. 

1964 did have several mini-patterns of geographic clustering, though nowhere to the sheer breadth of the 1934 program -

13 connecting to 17 (interesting corollary to the initial 13 being replaced by 17 in the 1930s)
57 paralleling 55
72 and 73 in Orange County near 74
76 added near 78/79
82/85/87 placed near 1961-era 84 in the Bay Area.  92 and (unbuilt? unsigned?) 93 are also in the Bay Area.
236/237/238 all supplanting former segments of Route 9, with unbuilt 230 and 239 in the Bay region as well.
115 near 111
240 and 243 as extensions of I-605, with unbuilt 241 (1964-1965) in downtown Los Angeles and unbuilt 249 in Sunland/Palmdale.
unbuilt 143 and 148 in metro Sacramento
unbuilt 81 paralleling 83
52/54/56 in San Diego
121 and 128 in Napa wine country
Could argue 201 near 190 is somewhat in this vein.
69 as the original number for former 65 (now 245 due to sign theft).
There were 3 child routes created between 1964 and 1972: Route 242 (former Route 24 and signed as such until 1989), Route 330, and Route 371.


In the 1950s, 43 and 63 were created parallel to 41 and 65 respectively.  156 essentially is a 1930s child route of 152, much like 88 could be seen as a child route of the original 8 (and 107 most notably is former 7).

The most recent pattern/clustering are the Orange County toll roads, 241/261 and the now renumbered 231.

[Max Rockatansky]

Some of the pre-1964 route numbers were solid choices like 43, 63 and 156.  I'm sure agency priorities were definitely shifted towards getting the Interstates open rather than numbering conventions.  Two things I've always fundamentally disagreed with regarding the 1964 renumbering is the number duplication between different levels of roads was a no-go and multiplexes were a negative.  Almost every other state in the country is fine with number duplications and long multiplexes.  Had those two issues been factored out it would have drawn into question if the renumbering was even necessary to begin with or possibly could have made it more flexible.  I'd argue that number duplication with US Routes should have been allowed in the 1934 State Highway grid.

[TheStranger]

Some of the pre-1964 route numbers were solid choices like 43, 63 and 156.  I'm sure agency priorities were definitely shifted towards getting the Interstates open rather than numbering conventions.  Two things I've always fundamentally disagreed with regarding the 1964 renumbering is the number duplication between different levels of roads was a no-go and multiplexes were a negative.  Almost every other state in the country is fine with number duplications and long multiplexes.  Had those two issues been factored out it would have drawn into question if the renumbering was even necessary to begin with or possibly could have made it more flexible.  I'd argue that number duplication with US Routes should have been allowed in the 1934 State Highway grid.

I would even say that some states from the very start were okay with US and Interstate routes duplicating as long as they didn't intersect (Illinois has this with I-24 and US 24, IIRC). 

They did want to get rid of some of the 3+ route concurrencies like the famous 60/70/99/10 and 15/395/91/18.  I can understand that to a degree.

Do kinda get why 6 got truncated, as the north-south segment really had very little through utility with the existing east-west portion from Bishop onward.

The biggest loss IMO in the whole thing would be US 99, which could have easily remained a single-state US route at over 300 miles. 

And for trying to prep for future interstate numbering, it's interesting that 115 was established in 1964 and 180 not renumbered - with 180's existence ultimately precluding the proposed I-180 of the 1980s (which ended up being added to I-580 instead), arguably leading to the whole I-238 thing.  Certainly long routes had been renumbered then to accommodate the Interstates (8, 5) and short ones too (15).

[hotdogPi]

I would even say that some states from the very start were okay with US and Interstate routes duplicating as long as they didn't intersect (Illinois has this with I-24 and US 24, IIRC). 

I think 24 in Illinois was the only example for quite a while.

[sparker]

Some of the pre-1964 route numbers were solid choices like 43, 63 and 156.  I'm sure agency priorities were definitely shifted towards getting the Interstates open rather than numbering conventions.  Two things I've always fundamentally disagreed with regarding the 1964 renumbering is the number duplication between different levels of roads was a no-go and multiplexes were a negative.  Almost every other state in the country is fine with number duplications and long multiplexes.  Had those two issues been factored out it would have drawn into question if the renumbering was even necessary to begin with or possibly could have made it more flexible.  I'd argue that number duplication with US Routes should have been allowed in the 1934 State Highway grid.

I would even say that some states from the very start were okay with US and Interstate routes duplicating as long as they didn't intersect (Illinois has this with I-24 and US 24, IIRC). 

They did want to get rid of some of the 3+ route concurrencies like the famous 60/70/99/10 and 15/395/91/18.  I can understand that to a degree.

Do kinda get why 6 got truncated, as the north-south segment really had very little through utility with the existing east-west portion from Bishop onward.

The biggest loss IMO in the whole thing would be US 99, which could have easily remained a single-state US route at over 300 miles. 

And for trying to prep for future interstate numbering, it's interesting that 115 was established in 1964 and 180 not renumbered - with 180's existence ultimately precluding the proposed I-180 of the 1980s (which ended up being added to I-580 instead), arguably leading to the whole I-238 thing.  Certainly long routes had been renumbered then to accommodate the Interstates (8, 5) and short ones too (15).

It's always interesting to note that US 6's truncation in Bishop -- even as late as '64 -- might have been considered temporary -- that it was calculated that someday, by hook, crook, or tunnel, CA 168's east and west sections would have been connected "over the top", and US 6 would have a direct path into Fresno (note that pre-'64, both parts of 168 west of US 395, as well as US 6 from Bishop to the state line, were all part of LRN 76) and then via (choose one) CA 180 west or CA 41 south to I-5 and potentially US 101.   The fact that in '64 the I-15 San Diego extension wasn't yet in the cards -- and that US 395 still was intended to fill the role of an inland N-S San Diego accessway, probably tipped the scales in its favor when the decision was made to eliminate the long 6/395 multiplex. 

Also, CA 115 was simply a carryover of SSR 115, established back after WW II; "Bear" shields and all that!   I have yet to see any proposal for an "I-115" (aside from the abortive original Interstate auxiliary route scheme circa 1957) as a "child" of I-15 within CA. 

I would even say that some states from the very start were okay with US and Interstate routes duplicating as long as they didn't intersect (Illinois has this with I-24 and US 24, IIRC). 

I think 24 in Illinois was the only example for quite a while.

It's likely that with both I-40 and I-80 intended from the beginning to traverse CA, where both US highways existed, CA, with its elongated N-S axis, was always considered to be an exception to the initial no-duplication concept -- one that was "worked out" (but apparently to no one's complete satisfaction!) with the in-state renumbering of '64.  Curiously, I-24 seems a bit far north for its grid position; the duplication in IL could have easily been avoided by simply swapping I-24 and I-26 -- not that anyone cares at this juncture!

[TheStranger]

Also, CA 115 was simply a carryover of SSR 115, established back after WW II; "Bear" shields and all that!   I have yet to see any proposal for an "I-115" (aside from the abortive original Interstate auxiliary route scheme circa 1957) as a "child" of I-15 within CA. 

Ooh, I hadn't realized 115 was created that early (until I looked at Cahighways).  Its placement near the longstanding Route 111 does seem to fit the pre-1964 child routes that are mentioned earlier in the thread (88 from 8, 26 from the original 1934-1936 Route 6, 107 from 7, and 43/63/156).

One could even view 111 and 115 as a mini grid sequence though 115 is not original to the 1934 numbering.

[Max Rockatansky]

Regarding US 6 over the path of CA 168, I couldn't fathom that highway ever being completed even with all the pre-environmental red tape optimism that was out there.   Realistically the best idea anyone ever came up with for a highway crossing in the general proximity of Bishop Area was the San Joaquin River at the end of CA 203.  With a simple adoption of new highway north of Crawley Lake that would made for a pretty handy route.

[sparker]

Regarding US 6 over the path of CA 168, I couldn't fathom that highway ever being completed even with all the pre-environmental red tape optimism that was out there.   Realistically the best idea anyone ever came up with for a highway crossing in the general proximity of Bishop Area was the San Joaquin River at the end of CA 203.  With a simple adoption of new highway north of Crawley Lake that would made for a pretty handy route.

Maybe as observers from the 2010's who've seen nearly a century go by without a state or federal maintained Sierra crossing between CA 178 and CA 120/Tioga Pass Road, we have the luxury of decades of hindsight.  But the system originators between 1926 and 1934 clearly saw the feat as at least eventually feasible -- the two unfinished cross-Sierra routes, 168 and 190, were on their "to do" list as LRN's 76 & 127 respectively starting with the system's inception.  And 1963, when the system renumbering and revamping was in the works, the system was still in its virtual youth at 37 total and 29 with full signage.  But obviously by decidedly not making the west and center sections of CA 168 something like "CASR 6", they were by that time walking back any previous long-range plans while still considering the corridor from Fresno to Bishop as one numbered corridor (neither section east of the Sierra ridgeline got signage until after '64).  But now 55+ years down the line reality has sunk in;  anything within 20 miles of Kaiser Pass is a dead issue.  And I agree that the best chance for any sort of cross-Sierra routing in that area would be right down the San Joaquin headwaters from Devils' Postpile, starting west from CA 203.  Of course, I'd do some designation switching if that were ever to become reality:  that whole section would become simply CA 168; 203 would move a bit south and take over the center "stub" section of CA 168 west of Bishop, while the eastern section over Westgard Pass would be the long-missing CA 264 -- in this way, the portion of CA 266 north of present CA 168 would become the eastern end of CA 264 to match NV 264, while the southern end would remain CA 266 to match, well, NV 266.  And yeah, I've thought about this for some time now (someone had to!).   

[mrsman]

Regarding US 6 over the path of CA 168, I couldn't fathom that highway ever being completed even with all the pre-environmental red tape optimism that was out there.   Realistically the best idea anyone ever came up with for a highway crossing in the general proximity of Bishop Area was the San Joaquin River at the end of CA 203.  With a simple adoption of new highway north of Crawley Lake that would made for a pretty handy route.

Maybe as observers from the 2010's who've seen nearly a century go by without a state or federal maintained Sierra crossing between CA 178 and CA 120/Tioga Pass Road, we have the luxury of decades of hindsight.  But the system originators between 1926 and 1934 clearly saw the feat as at least eventually feasible -- the two unfinished cross-Sierra routes, 168 and 190, were on their "to do" list as LRN's 76 & 127 respectively starting with the system's inception.  And 1963, when the system renumbering and revamping was in the works, the system was still in its virtual youth at 37 total and 29 with full signage.  But obviously by decidedly not making the west and center sections of CA 168 something like "CASR 6", they were by that time walking back any previous long-range plans while still considering the corridor from Fresno to Bishop as one numbered corridor (neither section east of the Sierra ridgeline got signage until after '64).  But now 55+ years down the line reality has sunk in;  anything within 20 miles of Kaiser Pass is a dead issue.  And I agree that the best chance for any sort of cross-Sierra routing in that area would be right down the San Joaquin headwaters from Devils' Postpile, starting west from CA 203.  Of course, I'd do some designation switching if that were ever to become reality:  that whole section would become simply CA 168; 203 would move a bit south and take over the center "stub" section of CA 168 west of Bishop, while the eastern section over Westgard Pass would be the long-missing CA 264 -- in this way, the portion of CA 266 north of present CA 168 would become the eastern end of CA 264 to match NV 264, while the southern end would remain CA 266 to match, well, NV 266.  And yeah, I've thought about this for some time now (someone had to!).   

CA in the Pat Brown era of the 1950's and 1960's was very much a can-do attitude.  They planned to build a highway and the thought was that nothing will stand in the way of their progress.

Of course, not all of their plans actually came to fruition.

[sparker]

Regarding US 6 over the path of CA 168, I couldn't fathom that highway ever being completed even with all the pre-environmental red tape optimism that was out there.   Realistically the best idea anyone ever came up with for a highway crossing in the general proximity of Bishop Area was the San Joaquin River at the end of CA 203.  With a simple adoption of new highway north of Crawley Lake that would made for a pretty handy route.

Maybe as observers from the 2010's who've seen nearly a century go by without a state or federal maintained Sierra crossing between CA 178 and CA 120/Tioga Pass Road, we have the luxury of decades of hindsight.  But the system originators between 1926 and 1934 clearly saw the feat as at least eventually feasible -- the two unfinished cross-Sierra routes, 168 and 190, were on their "to do" list as LRN's 76 & 127 respectively starting with the system's inception.  And 1963, when the system renumbering and revamping was in the works, the system was still in its virtual youth at 37 total and 29 with full signage.  But obviously by decidedly not making the west and center sections of CA 168 something like "CASR 6", they were by that time walking back any previous long-range plans while still considering the corridor from Fresno to Bishop as one numbered corridor (neither section east of the Sierra ridgeline got signage until after '64).  But now 55+ years down the line reality has sunk in;  anything within 20 miles of Kaiser Pass is a dead issue.  And I agree that the best chance for any sort of cross-Sierra routing in that area would be right down the San Joaquin headwaters from Devils' Postpile, starting west from CA 203.  Of course, I'd do some designation switching if that were ever to become reality:  that whole section would become simply CA 168; 203 would move a bit south and take over the center "stub" section of CA 168 west of Bishop, while the eastern section over Westgard Pass would be the long-missing CA 264 -- in this way, the portion of CA 266 north of present CA 168 would become the eastern end of CA 264 to match NV 264, while the southern end would remain CA 266 to match, well, NV 266.  And yeah, I've thought about this for some time now (someone had to!).   

CA in the Pat Brown era of the 1950's and 1960's was very much a can-do attitude.  They planned to build a highway and the thought was that nothing will stand in the way of their progress.

Of course, not all of their plans actually came to fruition.

Quite a few of those plans were dashed in the mid-70's when Adriana Gianturco assumed the directorship after being appointed by Jerry Brown in his first gubernatorial term ('75-'83).  But yes, some of those plans could arguably be described as "pie-in-the-sky" -- particularly with the myriad freeway/expressway segments criss-crossing both urban and rural territory (look at the initial 1959 iteration of the state's Freeway & Expressway System to illustrate this -- a prime and telling example are the multiple routes crossing the San Gabriel Mountains north of SSR 2 [LRN61]).  I was born & raised at the foot of those mountains; even as a kid, my reaction to all those corridors was WTF!? -- just surveying most of those routes would have been a major and treacherous undertaking -- much less actually attempting construction through and across many of those vertically challenging canyons!  System revisions in 1965 and 1969 (which deleted some of the more egregious corridor segments) preceded the Gianturco rollback -- but by that time political considerations (fomented by both sociopolitical and NIMBY sentiments) were impinging on the system's prospects.  By the time the Division of Highways morphed into the more "omnibus" Caltrans in 1973, many of the agency's internal attitudes had assumed a decidedly cynical tone (according to my relatives who worked there during that period), which geared up to virtual fatalism during the Gianturco years.  But even after relative order had been restored in the '80's and some roadway expansion had resumed, there was never a return to the exuberance of the '50's and '60's in post-Prop 13 state agencies, including Caltrans.  It could be argued that the inflationary '70's had contributed to the malaise -- you just couldn't build as much with devalued dollars -- but the simple fact is that the previous enthusiasm had given way to a grudging acceptance of the reality that you can't build everything everywhere, as the original system iteration had suggested. 

[TheStranger]

One thing that also comes to mind post-1976 is how few new routes have been designated.  But in a way that makes sense when the modern California system seems to be about using state shields to mark maintenance responsibility, rather than providing navigational assistance.

Case in point:

In the recent San Diego/US 395/Route 163 thread, Mapmikey discovered those 1970 videos showing several key surface streets in downtown, with the most notable find being US 395 and Route 163 existing concurrently along Market Street back then and even being extended 2 blocks south along old US 101/Pacific Highway!  Post-1964 saw many more routes getting signed than had been the case in the LRN era beforehand, with some surface road extensions being created after 1965 (Route 3 comes to mind).

Today, the San Diego area has only two surface street state routes west of Route 125 (Route 282 and Route 75), of which the suburban portion in Coronado is potentially being relinquished.

I totally understand cities not wanting CalTrans rules imposed on their streets, and I do get that GPS has made navigation easier than in the past.  But I also still strongly think that the ultimate point of numbering routes is to provide unified routings for drivers to follow, ahead of marking whether CalTrans is maintaining a route or not.

[sparker]

One thing that also comes to mind post-1976 is how few new routes have been designated.  But in a way that makes sense when the modern California system seems to be about using state shields to mark maintenance responsibility, rather than providing navigational assistance.

Case in point:

In the recent San Diego/US 395/Route 163 thread, Mapmikey discovered those 1970 videos showing several key surface streets in downtown, with the most notable find being US 395 and Route 163 existing concurrently along Market Street back then and even being extended 2 blocks south along old US 101/Pacific Highway!  Post-1964 saw many more routes getting signed than had been the case in the LRN era beforehand, with some surface road extensions being created after 1965 (Route 3 comes to mind).

Today, the San Diego area has only two surface street state routes west of Route 125 (Route 282 and Route 75), of which the suburban portion in Coronado is potentially being relinquished.

I totally understand cities not wanting CalTrans rules imposed on their streets, and I do get that GPS has made navigation easier than in the past.  But I also still strongly think that the ultimate point of numbering routes is to provide unified routings for drivers to follow, ahead of marking whether CalTrans is maintaining a route or not.

In the case of rural surface routes, shields are used for both maintenance and navigational purposes -- although at times those seemed to be at odds with one another (CA 137 west of Tulare being a prime example).  But urban surface routes were all about maintenance responsibilities, since after the mid- '30's more often than not there were viable alternate arterials to the state network in most metro areas, many decidedly more efficient in terms of getting a driver from point A to B.  The only useful non-maintenance aspect of urban state highways was their value as "default" routes for out-of-area drivers unfamiliar with a given region.  But the relationship between the state system (and the Division of Highways) and the individual jurisdictions -- towns & counties -- varied greatly.  Some towns prized "their" state route, particularly if it consistently provided local businesses with customers; others found the constant flow of traffic to be incompatible with their view of how a town should function.  Just peruse the late lamented California Highways & Public Works; the pages are full of projects to pull traffic away from town "main streets" yet keep the nascent bypass close enough so travelers didn't have to venture too far to access points of interest (e.g., the many reroutes of SSR 49 in the "Gold Country" Sierra foothills).  Until the more comprehensive Freeway & Expressway System was initiated in '59, most of these realignments were done at the behest of the various towns served by state routes.  Moving state routes onto brand-new alignments was one thing, but the process the Division of Highways (and Caltrans later) avoided (like the plague!) was simply shifting routings to other existing streets in urban areas -- a process that involved not only transferring legal responsibilities for facilities but also information as to construction details, what utilities were under said streets, easements, and myriad similar details -- particularly if those facilities were expected to host heavy commercial traffic. 

So, yeah -- the denser the area, the more ownership outweighs navigation as criteria for route deployment and signage (although the latter hasn't been prioritized for some time).  It's also the rationale for the rash of relinquishments over the last couple of decades -- absent a compelling navigational purpose, Caltrans sees little if any need to continue to maintain urban surface thoroughfares when the maintenance of freeways sucks up much of the available funds.  The message sent by Caltrans couldn't be any clearer -- they'll do freeways; but it's up to the locals to deal with the streets.   

[TheStranger]

In the case of rural surface routes, shields are used for both maintenance and navigational purposes -- although at times those seemed to be at odds with one another (CA 137 west of Tulare being a prime example).  But urban surface routes were all about maintenance responsibilities, since after the mid- '30's more often than not there were viable alternate arterials to the state network in most metro areas, many decidedly more efficient in terms of getting a driver from point A to B.  The only useful non-maintenance aspect of urban state highways was their value as "default" routes for out-of-area drivers unfamiliar with a given region.  But the relationship between the state system (and the Division of Highways) and the individual jurisdictions -- towns & counties -- varied greatly.  Some towns prized "their" state route, particularly if it consistently provided local businesses with customers; others found the constant flow of traffic to be incompatible with their view of how a town should function.  Just peruse the late lamented California Highways & Public Works; the pages are full of projects to pull traffic away from town "main streets" yet keep the nascent bypass close enough so travelers didn't have to venture too far to access points of interest (e.g., the many reroutes of SSR 49 in the "Gold Country" Sierra foothills).  Until the more comprehensive Freeway & Expressway System was initiated in '59, most of these realignments were done at the behest of the various towns served by state routes.  Moving state routes onto brand-new alignments was one thing, but the process the Division of Highways (and Caltrans later) avoided (like the plague!) was simply shifting routings to other existing streets in urban areas -- a process that involved not only transferring legal responsibilities for facilities but also information as to construction details, what utilities were under said streets, easements, and myriad similar details -- particularly if those facilities were expected to host heavy commercial traffic. 

So, yeah -- the denser the area, the more ownership outweighs navigation as criteria for route deployment and signage (although the latter hasn't been prioritized for some time).  It's also the rationale for the rash of relinquishments over the last couple of decades -- absent a compelling navigational purpose, Caltrans sees little if any need to continue to maintain urban surface thoroughfares when the maintenance of freeways sucks up much of the available funds.  The message sent by Caltrans couldn't be any clearer -- they'll do freeways; but it's up to the locals to deal with the streets.   

Part of the modern problem is that even critical, non-urban state routes do not have the best signage at times (Route 18 between the Antelope Valley and I-15 was noticeably devoid of shields ca. 2012, and IIRC Route 128 between Route 121 and Winters also was very lacking in trailblazers back then).   It's weird to think that the tiny Route 77 freeway in Oakland, not marked off of I-880 in any way, has trailblazers, yet the aforementioned regional routes were severely lacking at one point.


This does beg a longstanding question: when the 1934 route numbering system came about, since the signage was provided by CSAA and ACSC, who made the final decisions as to which routes went where?  Other than the US routes, the only guidelines beforehand were the LRNs and while those highlighted what the state maintained, the sign numbers created in 1934 were rarely tied down to one LRN.

While certainly not every urban arterial or rural connector is worthy of numbering, creating efficient pathways for those routes that are signed could be prioritized a lot more.  (Example to my mind: even if the Route 84 new-terrain realignment east of I-880 never happens, wouldn't putting 84 down Decoto and Mission be a less convoluted routing than the current surface streets through Fremont?)

[sparker]

^^^^^^^^^
AFAIK, the state highway commission has always been the final determinant of route numbers (at least those not the parvenu of AASHO/AASHTO).  But that in itself has been and is dependent upon administrative decisions within the Division of Highways or, later, Caltrans.  How much input comes (or historically has come) from the district offices is indeterminate; aside from CA 7 and CA 11 there hasn't been much activity in this area for decades.  Maybe I'm just being cynical, but I'll bet the initial choice is determined by some mid-level agency administrator or assistant who is handed the file of available numbers and simply selects one -- this would account for 7 and 11 being assigned to relatively short border servers -- they would have been 1st and 2nd on the unused list, and happy hour was looming!  Bada bing, bada bam -- done!    Given the present level of agency attention paid to numbering and continuity, such a scenario is entirely plausible!

BTW, the CA 84 surface street maze through Fremont is up for relinquishment, and no replacement offered (although Decoto would be appropriate).  However, there are no remaining reassurance shields on CA 238/Mission save the existing CA 84 junction points, so D4 plainly either doesn't care or is deliberately "lowballing" the Fremont surface alignments pending even more relinquishment.       

[Quillz]

The biggest loss IMO in the whole thing would be US 99, which could have easily remained a single-state US route at over 300 miles.

I've said this before (although I can't find the topic where I've said it): California should have done what Oregon does and use US routes for business loops/spurs. US-99 would have been perfect for this. CA-273, CA-265, CA-263 function as business loops to I-5. They should have just stayed as US-99.

Especially since in the very same year, Caltrans had zero problems creating implied concurrencies. CA-1 exists in multiple pieces, with implied concurrencies with US-101. (And generally unsigned, with a few exceptions). So what was the issue with keeping US-99 around this way? It would have worked perfectly: no need to renumber, the route exists via implied concurrency, then Oregon and Washington could have also kept US-99 and have it function the same way.

I've read that Caltrans apparently loved the green spades so much that they effectively killed off a lot of US routes just to use it. That seems like a strange reason, but I guess it would explain why US-99 was gutted the way it was. (And it just seems replacing one number with multiple went against the entire philosophy of simplifying).

[Max Rockatansky]

Division of Highways you mean?  Caltrans wasn't an entity for about another decade by the time the green spade became a thing.

[Quillz]

Division of Highways you mean?  Caltrans wasn't an entity for about another decade by the time the green spade became a thing.

Yes, whoever was in charge of things at the time. I found a 1963 article or so that mentioned the new green spades were deliberately replacing some older US highways. Seems to suggest that was a big motivation, especially in cases where the US highways just had the same number but as a state highway (60, 99). (Although I guess the official reason was those two were under 300 miles).

[Max Rockatansky]

Division of Highways you mean?  Caltrans wasn't an entity for about another decade by the time the green spade became a thing.

Yes, whoever was in charge of things at the time. I found a 1963 article or so that mentioned the new green spades were deliberately replacing some older US highways. Seems to suggest that was a big motivation, especially in cases where the US highways just had the same number but as a state highway (60, 99). (Although I guess the official reason was those two were under 300 miles).

The January/February 1964 issue of California Highways & Public Works if I recall correctly touted the benefits of the green space.

[Quillz]

I would like to see a modern day study. I wonder if the notion that white-on-green holds up better than black-on-white in certain driving conditions is still the conclusion. Especially if the testing back then was done with older shields, and particularly the porcelain enamel ones.

[Max Rockatansky]

I tend to agree that the green spades are either to see in Tule Fog over anything white.