CA 71

[Max Rockatansky]

California State Route 71 is a 16-mile state highway which exists in the Los Angeles Metropolitan area.  California State Route 71 begins at California State Route 57 in Pomona.  From California State Route 57 the routing of California State Route 71 is generally comprised the Chino Valley Freeway south to California State Route 91.  California State Route 71 is one of the original Sign State Route designations from 1934.  California State Route 71 once spanned from US Route 66 in Claremont south to US Route 80 in San Diego.  Portions of California State Route 71 would in time become components of US Route 395, Interstate 15, California State Route 215, California State Route 79 and California State Route 371.  Featured as the blog cover is California State Route 71 passing through Temescal Canyon during 1941.

https://www.gribblenation.org/2023/11/california-state-route-71.html?m=1

[bing101]

I remember this one CA-71 had an at grade section even though its called Chino Valley Freeway.

[Quillz]

CA-71 is one of the most interesting routes from a historical perspective, given how drastically it changed. Reminds me a lot of CA-24 in NorCal, now the modern routing is such a small portion of the full extent.

[Alps]

I remember this one CA-71 had an at grade section even though its called Chino Valley Freeway.

When I clinched CA 71, they were just starting to convert the last, northernmost signal to an interchange. Work is long done and that half hour of delay is long gone.

[cahwyguy]

CA-71 is one of the most interesting routes from a historical perspective, given how drastically it changed. Reminds me a lot of CA-24 in NorCal, now the modern routing is such a small portion of the full extent.

It's also one of five routes in the state with backwards postmiles (i.e., going from N to S), because of its history. The others are Route 153, Route 282, I-580, and I-780. This is because the postmiles date to the 1964 Route 71, which was a West-East route.

[Occidental Tourist]

CA 72 (or what's left of it) has backwards postmiles because it used to be US 101.  CA 18 has backwards postmiles (it's western terminus is east of its eastern terminus) because it's a Frankenstein route.

[cahwyguy]

CA 72 (or what's left of it) has backwards postmiles because it used to be US 101.  CA 18 has backwards postmiles (it's western terminus is east of its eastern terminus) because it's a Frankenstein route.

Nope. CA 72 has postmiles in the correct direction. It is a N/S route, and the postmiles start at 0 at the southern end in each county. Postmiles were first used after the 1964 renumbering (what, you didn't listen to our podcast on the subject: https://caroutebyroute.org/2023/01/16/carxr-1-07-highway-numbering-state-highways-and-post-miles/ ), and the Route 72 postmiles date from the creation of Route 72 then. It does not have US 101 postmiles (and in any case, the US 101 postmiles are also N/S postmiles, starting in the south).

As for Route 18. The definition has the first segment of the route "From Route 10 near San Bernardino to Route 210.". Postmiles started at Route 10, and it is a N/S route. This continues to the end of the route. So it may appear they are backward in LA county, but they are correct FOR A NORTH SOUTH route with a small segment going laterally.

[dbz77]

As for Route 18. The definition has the first segment of the route "From Route 10 near San Bernardino to Route 210.". Postmiles started at Route 10, and it is a N/S route. This continues to the end of the route. So it may appear they are backward in LA county, but they are correct FOR A NORTH SOUTH route with a small segment going laterally.

So basically, Route 18 starts at the 10/215 Interchange, and goes to the Waterman Avenue exit on Route 210?

[Max Rockatansky]

As for Route 18. The definition has the first segment of the route "From Route 10 near San Bernardino to Route 210.". Postmiles started at Route 10, and it is a N/S route. This continues to the end of the route. So it may appear they are backward in LA county, but they are correct FOR A NORTH SOUTH route with a small segment going laterally.

So basically, Route 18 starts at the 10/215 Interchange, and goes to the Waterman Avenue exit on Route 210?

No, the legislative definition is referring to an unconstructed segment between 10 and 210.  The freeway adoption in the corridor was deleted in 1975.  There was never any follow up to delete the segment from the legislative definition.

[Occidental Tourist]

CA 72 (or what's left of it) has backwards postmiles because it used to be US 101.  CA 18 has backwards postmiles (it's western terminus is east of its eastern terminus) because it's a Frankenstein route.

Nope. CA 72 has postmiles in the correct direction. It is a N/S route, and the postmiles start at 0 at the southern end in each county. Postmiles were first used after the 1964 renumbering (what, you didn't listen to our podcast on the subject: https://caroutebyroute.org/2023/01/16/carxr-1-07-highway-numbering-state-highways-and-post-miles/ ), and the Route 72 postmiles date from the creation of Route 72 then. It does not have US 101 postmiles (and in any case, the US 101 postmiles are also N/S postmiles, starting in the south).

As for Route 18. The definition has the first segment of the route "From Route 10 near San Bernardino to Route 210.". Postmiles started at Route 10, and it is a N/S route. This continues to the end of the route. So it may appear they are backward in LA county, but they are correct FOR A NORTH SOUTH route with a small segment going laterally.

You're correct about Route 72.  But I'm stumped about where Caltrans records or designates Route 18 as a north/south route.  In the field they only sign it as east/west or nothing at all. From Waterman Avenue up to Rim of the World Highway, it's signed east and west. In Running Springs, it's signed east and west. At the 15, it's signed east and west.  And at its terminus at Route 138, it's signed as 18 east.







Even the most geographically north/south segment between Big Bear and Lucerne Valley is signed . . . with no cardinal direction at all. Not in Big Bear, Lucerne Valley, or any point in between.



The Caltrans Bridge Log contains one north/south reference for 18; it's for the 138 interchange, which as noted above, is nonetheless signed as east and west. I also see that CHP incident reports will refer to northbound and southbound 18, which is as confusing as hell, particularly when they are talking about incidents on the Palmdale Avenue segment of 18.

[cahwyguy]

You're correct about Route 72.  But I'm stumped about where Caltrans records or designates Route 18 as a north/south route.  In the field they only sign it as east/west or nothing at all. From Waterman Avenue up to Rim of the World Highway, it's signed east and west. In Running Springs, it's signed east and west. At the 15, it's signed east and west.  And at its terminus at Route 138, it's signed as 18 east.

We all know cardinal direction signage is suspect -- they sign US 101, which is a N/S route, as E/W in the San Fernando Valley. You have to go by how the route is defined legislatively, and in this case, that's a N/S route. There are three segments, defined in a south to north order: the unbuilt I-10 to I-210 segment, the I-210 to I-15 segment, and the I-15 to Route 138 segment. The historic sign route 18 was even longer, as Tom's recent blog discussed, and was also clearly N/S.

Remember, we are dealing with Caltrans and the legislature here. It doesn't always make sense. But if this route was to have E/W postmiles, it would be defined as running from Route 138 to I-15, I-15 to I-210, and I-210 to I-10 ... and that's not the legislative definition.

[FredAkbar]

It's also one of five routes in the state with backwards postmiles (i.e., going from N to S), because of its history. The others are Route 153, Route 282, I-580, and I-780. This is because the postmiles date to the 1964 Route 71, which was a West-East route.

I-580 is signed as east-west so the postmiles are correct.

[cahwyguy]

It's also one of five routes in the state with backwards postmiles (i.e., going from N to S), because of its history. The others are Route 153, Route 282, I-580, and I-780. This is because the postmiles date to the 1964 Route 71, which was a West-East route.

I-580 is signed as east-west so the postmiles are correct.

Remember: Postmiles go from West to East, South to North. If your postmiles are increasing East to West, the route is postmiled-backwards. Route 580, as defined, starts with "From Route 5 southwest of Vernalis to Route 80 in Oakland via the vicinity of Dublin and Hayward." The post miles are defined as if it was a S to N route. If the postmiles were in the correct direction, they would start at 0 at US 101 in Marin, which is the westernmost part of the route. But they don't. I-580 and US 101 is approximately MRN 4.735 according to the postmile tool. MRN 0 is in the middle of the bay.

So the postmiles on I-580 are numbered from East to West, when if they were in the right order, they would go from West to East. They were defined when I-580 was still a South to North route, before the segment of Route 17 across the top of the bay was added.

[TheStranger]

So the postmiles on I-580 are numbered from East to West, when if they were in the right order, they would go from West to East. They were defined when I-580 was still a South to North route, before the segment of Route 17 across the top of the bay was added.

IIRC, I-580 has never been signed North/South at any point.  So is the original route definition (from 5 to 80) a carryover from when the route was part of I-5W?

I-5W itself was signed east/west based on that one photo of the MacArthur Freeway sighted in a CHPW magazine issue, at least from what I recall.

[Max Rockatansky]

So the postmiles on I-580 are numbered from East to West, when if they were in the right order, they would go from West to East. They were defined when I-580 was still a South to North route, before the segment of Route 17 across the top of the bay was added.

IIRC, I-580 has never been signed North/South at any point.  So is the original route definition (from 5 to 80) a carryover from when the route was part of I-5W?

I-5W itself was signed east/west based on that one photo of the MacArthur Freeway sighted in a CHPW magazine issue, at least from what I recall.

July/August 1962 volume specifically.  I believe the placard in the photo was originally posted for US 50.


Fixed quoting. —Roadfro

[cahwyguy]

So the postmiles on I-580 are numbered from East to West, when if they were in the right order, they would go from West to East. They were defined when I-580 was still a South to North route, before the segment of Route 17 across the top of the bay was added.

IIRC, I-580 has never been signed North/South at any point.  So is the original route definition (from 5 to 80) a carryover from when the route was part of I-5W?

I-5W itself was signed east/west based on that one photo of the MacArthur Freeway sighted in a CHPW magazine issue, at least from what I recall.

Irrespective of how it is signed in the field, it is how it is defined legislatively that seems to dictate postmile order. It is defined from S to N, and in terms of field directional signage, you would probably have to look at the route as in 1964, at which point it only went from I-5 to I-80. It could have been signed S/N then (changing from I-5W, possibly), and then been changed to W/E when the portion of Route 17 across the top of the bay was added. But whatever it is, it is. It is currently a route signed and treated as E/W, but the postmiles start at the eastern end.

[FredAkbar]

Remember: Postmiles go from West to East, South to North. If your postmiles are increasing East to West, the route is postmiled-backwards. Route 580, as defined, starts with "From Route 5 southwest of Vernalis to Route 80 in Oakland via the vicinity of Dublin and Hayward." The post miles are defined as if it was a S to N route. If the postmiles were in the correct direction, they would start at 0 at US 101 in Marin, which is the westernmost part of the route. But they don't. I-580 and US 101 is approximately MRN 4.735 according to the postmile tool. MRN 0 is in the middle of the bay.

So the postmiles on I-580 are numbered from East to West, when if they were in the right order, they would go from West to East. They were defined when I-580 was still a South to North route, before the segment of Route 17 across the top of the bay was added.

I know that I said "east-west" (as opposed to "west-east") but this was imprecise wording so I hope that didn't add to the confusion. I-580 exit numbers increase from West to East.

As for starting at 0 at US 101, the exit numbers at least seem to obey that. For example, here's Exit 7 which is 7 miles from the start of I-580 in Marin. Are you saying the postmiles are backwards from the exit numbers?

[cahwyguy]

Remember: Postmiles go from West to East, South to North. If your postmiles are increasing East to West, the route is postmiled-backwards. Route 580, as defined, starts with "From Route 5 southwest of Vernalis to Route 80 in Oakland via the vicinity of Dublin and Hayward." The post miles are defined as if it was a S to N route. If the postmiles were in the correct direction, they would start at 0 at US 101 in Marin, which is the westernmost part of the route. But they don't. I-580 and US 101 is approximately MRN 4.735 according to the postmile tool. MRN 0 is in the middle of the bay.

So the postmiles on I-580 are numbered from East to West, when if they were in the right order, they would go from West to East. They were defined when I-580 was still a South to North route, before the segment of Route 17 across the top of the bay was added.

I know that I said "east-west" (as opposed to "west-east") but this was imprecise wording so I hope that didn't add to the confusion. I-580 exit numbers increase from West to East.

As for starting at 0 at US 101, the exit numbers at least seem to obey that. For example, here's Exit 7 which is 7 miles from the start of I-580 in Marin. Are you saying the postmiles are backwards from the exit numbers?

Yes. Exit 7 EB is at approx CC R5.586. Exit 8 EB is at approx CC R4.058. You can see this for yourself in the postmile tool: https://postmile.dot.ca.gov/PMQT/PostmileQueryTool.html?

[heynow415]

Remember: Postmiles go from West to East, South to North. If your postmiles are increasing East to West, the route is postmiled-backwards. Route 580, as defined, starts with "From Route 5 southwest of Vernalis to Route 80 in Oakland via the vicinity of Dublin and Hayward." The post miles are defined as if it was a S to N route. If the postmiles were in the correct direction, they would start at 0 at US 101 in Marin, which is the westernmost part of the route. But they don't. I-580 and US 101 is approximately MRN 4.735 according to the postmile tool. MRN 0 is in the middle of the bay.

So the postmiles on I-580 are numbered from East to West, when if they were in the right order, they would go from West to East. They were defined when I-580 was still a South to North route, before the segment of Route 17 across the top of the bay was added.

I know that I said "east-west" (as opposed to "west-east") but this was imprecise wording so I hope that didn't add to the confusion. I-580 exit numbers increase from West to East.

As for starting at 0 at US 101, the exit numbers at least seem to obey that. For example, here's Exit 7 which is 7 miles from the start of I-580 in Marin. Are you saying the postmiles are backwards from the exit numbers?

Yes. Exit 7 EB is at approx CC R5.586. Exit 8 EB is at approx CC R4.058. You can see this for yourself in the postmile tool: https://postmile.dot.ca.gov/PMQT/PostmileQueryTool.html?

That's a legacy of the US101 to I-80 section originally being signed as SR17 when that went from Santa Cruz to San Rafael, which was a true N/S (or S/N) route before being truncated to I-280 when I-880 came into being.  The exit numbering came long after 17 was cut short and  I-580 was signed from 101 to I-5.  One could argue, given its starting and ending points and the general alignment of various sections, whether 580 should be considered a north-south or east-west route.

[JustDrive]

I mean, 580 is mostly N-S between San Rafael and Castro Valley, and again east of the 205 split. The remaining 31 miles are E-W.

[FredAkbar]

I mean, 580 is mostly N-S between San Rafael and Castro Valley, and again east of the 205 split. The remaining 31 miles are E-W.

580 from San Rafael to Castro Valley is only about 30 miles, so the 31 miles (the very clearly E-W section) is nothing to sneeze at. And it's pretty diagonal from I-205 to I-5. I think E-W is reasonable. If you zoom out on a map it's pretty clearly more E-W overall, unless you want to make the argument that the N-Sish portion (Richmond to CV) should be weighted more heavily in the decision because that area is more population-dense (no idea if this is a thing).

[RZF]

On a local level, within Southern California, US-101 is E/W from the 170/134 split to Gaviota in Santa Barbara County. That's a staggering distance of about 116 miles. I know in the SF Valley, there are a few signs guiding me to "101 West" or "101 East". Elsewhere, especially in Ventura County where US-101 is the main thoroughfare through the county going east/west in its entirety, it's signed "correctly" as N/S. So where do we draw the line?

[mrsman]

On a local level, within Southern California, US-101 is E/W from the 170/134 split to Gaviota in Santa Barbara County. That's a staggering distance of about 116 miles. I know in the SF Valley, there are a few signs guiding me to "101 West" or "101 East". Elsewhere, especially in Ventura County where US-101 is the main thoroughfare through the county going east/west in its entirety, it's signed "correctly" as N/S. So where do we draw the line?

The 101 west and east are LADOT signs not Caltrans.  Caltrans is consistent about signing 101 as a N/S, however the Ventura Freeway is definitely east/west, even along the 101 portion.  Some signage that shows the Ventura Fwy as E/W, usually without the 101 shield, but I do not know whether the signs are from Caltrans or from LADOT.

Some of this is even more confusing if applied to city streets.

Obviously, the old 101 ran along Ventura Blvd.  It was also N/S, but the addresses along Ventura Blvd match addresses for SFV east-west streets.  You travel north on (business) 101 but west along Ventura Blvd.

CA-2 also shares some of this confusion.  E-W through the forests and along the relinquished portions of Santa Monica Blvd, but N-S along the Glendale Fwy.