California highways with most concurrencies

[jpm]

Hi everyone.
Some trivial pursuit:
I was wondering that California highway has the most concurrencies with other highways?

The most I can figure out is 7 with CA-89 as it wanders through Northeast California.  It runs along with the following highways:
CA-44
CA-36
CA-70
CA-49
I-80
US 50
CA-88

CA-33 also has 7 (from North - South):
CA-140
CA-152
I-5
CA-198
CA-58
CA-166
CA-150

CA-49 has 6:

CA-89
CA-20
CA-88
CA-108
CA-120
CA-140


Are there any other highways with this many?

Thanks for the responses....

--jpm

[DTComposer]

Of course, technically California highways have no concurrences since they're not legislatively allowed.

That said, US-101 has:
CA-2
CA-23
CA-1
CA-1 (again)
CA-166
CA-1 (again)
CA-46
CA-156
CA-152
CA-84
CA-1 (again)
CA-116
CA-128
CA-20
CA-271

Even if you count the multiple CA-1 sections as one, US-101 has 12 concurrences. Also formerly had CA-170.

[Max Rockatansky]

99 is pretty up there too; 58, 59, 140, 120, 4, 50, 5 and 162. 

[Max Rockatansky]

What about most concurriencies in one place?  The most I can think of off the top of my head is 99/140/59 in Merced. 

[TheStranger]

What about most concurriencies in one place?  The most I can think of off the top of my head is 99/140/59 in Merced. 

WX Freeway in downtown/midtown Sacramento had Route 99/US 50/Business 80 until late 2016, and is part of the unsigned I-305.

Historically:

- the stretch of today's 215 in San Bernardino, at one point I-15/Route 18/US 66/91/395
- Wasn't there a part of the San Bernardino Freeway that was I-10/Route 39/US 60/70/99?  (Though I also remember reading on an earlier thread that 39 actually used frontage roads to connect Azusa Avenue with the now-deleted segment heading south towards Hacienda Heights)
- The portion of the Arroyo Seco Parkway (Pasadena Freeway) from the Four-Level to Avenue 26 was at one point Route 11/US 6/66/99.

[Max Rockatansky]

What about most concurriencies in one place?  The most I can think of off the top of my head is 99/140/59 in Merced. 

WX Freeway in downtown/midtown Sacramento had Route 99/US 50/Business 80 until late 2016, and is part of the unsigned I-305.

The only rub to I-305 is does the state "really"  recognize it?  I know it was on the FHWA books as a chargeable Interstate.  I'd still say I-80BL counts, if I recall correctly it is supposed to be signed by legislative decree even though it no longer is on US 50. 

[emory]

What about most concurriencies in one place?  The most I can think of off the top of my head is 99/140/59 in Merced. 

WX Freeway in downtown/midtown Sacramento had Route 99/US 50/Business 80 until late 2016, and is part of the unsigned I-305.

The only rub to I-305 is does the state "really"  recognize it?  I know it was on the FHWA books as a chargeable Interstate.  I'd still say I-80BL counts, if I recall correctly it is supposed to be signed by legislative decree even though it no longer is on US 50.

No. The state signs by legislative definition in the SHC, with very few exceptions. I-80 BL being one of them, which is actually CA 51. Similarly there is a segment of I-210 on CA 57 in San Dimas that is not recognized because I-210 separates from CA 210 at 57's northern terminus.

[TheStranger]

What about most concurriencies in one place?  The most I can think of off the top of my head is 99/140/59 in Merced. 

WX Freeway in downtown/midtown Sacramento had Route 99/US 50/Business 80 until late 2016, and is part of the unsigned I-305.

The only rub to I-305 is does the state "really"  recognize it?  I know it was on the FHWA books as a chargeable Interstate.  I'd still say I-80BL counts, if I recall correctly it is supposed to be signed by legislative decree even though it no longer is on US 50.

No. The state signs by legislative definition in the SHC, with very few exceptions. I-80 BL being one of them, which is actually CA 51. Similarly there is a segment of I-210 on CA 57 in San Dimas that is not recognized because I-210 separates from CA 210 at 57's northern terminus.

Isn't the legislative definition of Route 210 though essentially from San Fernando to Redlands, with the north-south Orange Freeway segment that was built as I-210 now part of the legislative definition of Route 57?

[Max Rockatansky]

What about most concurriencies in one place?  The most I can think of off the top of my head is 99/140/59 in Merced. 

WX Freeway in downtown/midtown Sacramento had Route 99/US 50/Business 80 until late 2016, and is part of the unsigned I-305.

The only rub to I-305 is does the state "really"  recognize it?  I know it was on the FHWA books as a chargeable Interstate.  I'd still say I-80BL counts, if I recall correctly it is supposed to be signed by legislative decree even though it no longer is on US 50.

No. The state signs by legislative definition in the SHC, with very few exceptions. I-80 BL being one of them, which is actually CA 51. Similarly there is a segment of I-210 on CA 57 in San Dimas that is not recognized because I-210 separates from CA 210 at 57's northern terminus.

Isn't the legislative definition of Route 210 though essentially from San Fernando to Redlands, with the north-south Orange Freeway segment that was built as I-210 now part of the legislative definition of Route 57?

Apparently as of 1998 it is:

https://www.cahighways.org/057-064.html#057

The Post Mile Tool shows mileage for CA 57.

[RZF]

What would be the longest freeway concurrency (concurrency between two full-length freeways)?

I can only think of CA-60 and I-215 for all that distance it covers in Riverside. Or CA-60 and CA-57 in Diamond Bar. Haha, what's up with the IE and combining freeways?

[emory]

What about most concurriencies in one place?  The most I can think of off the top of my head is 99/140/59 in Merced. 

WX Freeway in downtown/midtown Sacramento had Route 99/US 50/Business 80 until late 2016, and is part of the unsigned I-305.

The only rub to I-305 is does the state "really"  recognize it?  I know it was on the FHWA books as a chargeable Interstate.  I'd still say I-80BL counts, if I recall correctly it is supposed to be signed by legislative decree even though it no longer is on US 50.

No. The state signs by legislative definition in the SHC, with very few exceptions. I-80 BL being one of them, which is actually CA 51. Similarly there is a segment of I-210 on CA 57 in San Dimas that is not recognized because I-210 separates from CA 210 at 57's northern terminus.

Isn't the legislative definition of Route 210 though essentially from San Fernando to Redlands, with the north-south Orange Freeway segment that was built as I-210 now part of the legislative definition of Route 57?

Yes, and much like I-305, the state ignores it in favor of the state defined Route 50.

[jpm]

What would be the longest freeway concurrency (concurrency between two full-length freeways)?

I can only think of CA-60 and I-215 for all that distance it covers in Riverside. Or CA-60 and CA-57 in Diamond Bar. Haha, what's up with the IE and combining freeways?

Let's see what Google Maps sez:
CA-57/CA-60 - 1.6 miles (it always seemed longer than that...)
CA-22/I-405 - 2 miles (again, seems longer probably because of so much traffic on the San Diego Freeway)
I-80/I-580 - 3.8 miles
CA-60/I-215 -5.1 miles

and the winner is......

CA-99/I-5+US-50  - 9.2 miles

Hope I didn't miss any....

--jpm

[Occidental Tourist]

Wouldn't it be a freeway portion of a CA-1/US-101 concurrency?  Off the top of my head, the concurrency between La Conchita and Goleta would be the longest.

[sparker]

Wouldn't it be a freeway portion of a CA-1/US-101 concurrency?  Off the top of my head, the concurrency between La Conchita and Goleta would be the longest.

That gap in CA 1 -- actually between La Conchita and Las Cruces -- isn't actually defined as Route 1, just 101.  There are no CA 1 reassurance shields or trailblazers between those two points.  The other two functional coincidences -- between Pismo Beach and San Luis Obispo and US 101 at the Presidio in S.F. north to Mill Valley -- are dual-signed as US 101/CA 1.  And seeing as there's no official recognition of the CA 1/US 101 junction at Rice Avenue east of Oxnard, there are no roadside CA 1 reassurance shields on US 101 along that stretch from there to north of Ventura -- despite a few sporadic CA 1 shields on BGS's.   Not surprising, considering the La Conchita segment of CA 1 is only recognized and "trailblazed" from US 101 via smallish roadside green signs.  Personally, I consider that there are 2 1/2 concurrencies -- the longstanding signed ones in SLO County and over the GG Bridge; the "half" one would be between Oxnard and north of CA 33 in Ventura -- and only because of that occasional overhead BGS signage.   Between La Conchita and Las Cruces CA 1 doesn't get a peep in the way of recognition or signage.  Coincidentally, that "half" is located in Caltrans' District 7 (Ventura and L.A. counties); the long "unstated" stretch south of Las Cruces is in District 5 (Central Coast).  Different districts long have had different sign policies -- although neither of the two relevant here has an exemplary track record for accuracy and thoroughness.   Nonetheless, in a carryover from the old LRN/SSR days, there's only one legal route definition for any of the concurrencies, signed or not -- and it is always US 101. 

[JustDrive]

There's a glaring "END 1"  sign at Las Cruces, which blatantly makes the Las Cruces-to-Seacliff stretch not a concurrency. Conversely, before District 7 redid the signs at Seacliff, there was a "TO 1"  sign attached to the "Ventura Fwy 101 Santa Barbara"  sign, but now it just reads "101 1 NORTH."

[Bickendan]

Wouldn't it be a freeway portion of a CA-1/US-101 concurrency?  Off the top of my head, the concurrency between La Conchita and Goleta would be the longest.

That gap in CA 1 -- actually between La Conchita and Las Cruces -- isn't actually defined as Route 1, just 101.  There are no CA 1 reassurance shields or trailblazers between those two points.  The other two functional coincidences -- between Pismo Beach and San Luis Obispo and US 101 at the Presidio in S.F. north to Mill Valley -- are dual-signed as US 101/CA 1.  And seeing as there's no official recognition of the CA 1/US 101 junction at Rice Avenue east of Oxnard, there are no roadside CA 1 reassurance shields on US 101 along that stretch from there to north of Ventura -- despite a few sporadic CA 1 shields on BGS's.   Not surprising, considering the La Conchita segment of CA 1 is only recognized and "trailblazed" from US 101 via smallish roadside green signs.  Personally, I consider that there are 2 1/2 concurrencies -- the longstanding signed ones in SLO County and over the GG Bridge; the "half" one would be between Oxnard and north of CA 33 in Ventura -- and only because of that occasional overhead BGS signage.   Between La Conchita and Las Cruces CA 1 doesn't get a peep in the way of recognition or signage.  Coincidentally, that "half" is located in Caltrans' District 7 (Ventura and L.A. counties); the long "unstated" stretch south of Las Cruces is in District 5 (Central Coast).  Different districts long have had different sign policies -- although neither of the two relevant here has an exemplary track record for accuracy and thoroughness.   Nonetheless, in a carryover from the old LRN/SSR days, there's only one legal route definition for any of the concurrencies, signed or not -- and it is always US 101. 

Speaking of the GG Bridge, isn't it technically devoid of both US 101 and CA 1?

[Max Rockatansky]

Wouldn't it be a freeway portion of a CA-1/US-101 concurrency?  Off the top of my head, the concurrency between La Conchita and Goleta would be the longest.

That gap in CA 1 -- actually between La Conchita and Las Cruces -- isn't actually defined as Route 1, just 101.  There are no CA 1 reassurance shields or trailblazers between those two points.  The other two functional coincidences -- between Pismo Beach and San Luis Obispo and US 101 at the Presidio in S.F. north to Mill Valley -- are dual-signed as US 101/CA 1.  And seeing as there's no official recognition of the CA 1/US 101 junction at Rice Avenue east of Oxnard, there are no roadside CA 1 reassurance shields on US 101 along that stretch from there to north of Ventura -- despite a few sporadic CA 1 shields on BGS's.   Not surprising, considering the La Conchita segment of CA 1 is only recognized and "trailblazed" from US 101 via smallish roadside green signs.  Personally, I consider that there are 2 1/2 concurrencies -- the longstanding signed ones in SLO County and over the GG Bridge; the "half" one would be between Oxnard and north of CA 33 in Ventura -- and only because of that occasional overhead BGS signage.   Between La Conchita and Las Cruces CA 1 doesn't get a peep in the way of recognition or signage.  Coincidentally, that "half" is located in Caltrans' District 7 (Ventura and L.A. counties); the long "unstated" stretch south of Las Cruces is in District 5 (Central Coast).  Different districts long have had different sign policies -- although neither of the two relevant here has an exemplary track record for accuracy and thoroughness.   Nonetheless, in a carryover from the old LRN/SSR days, there's only one legal route definition for any of the concurrencies, signed or not -- and it is always US 101. 

Speaking of the GG Bridge, isn't it technically devoid of both US 101 and CA 1?

Correct, that's owned by the City of San Francisco.

[Max Rockatansky]

What would be the longest freeway concurrency (concurrency between two full-length freeways)?

I can only think of CA-60 and I-215 for all that distance it covers in Riverside. Or CA-60 and CA-57 in Diamond Bar. Haha, what's up with the IE and combining freeways?

Let's see what Google Maps sez:
CA-57/CA-60 - 1.6 miles (it always seemed longer than that...)
CA-22/I-405 - 2 miles (again, seems longer probably because of so much traffic on the San Diego Freeway)
I-80/I-580 - 3.8 miles
CA-60/I-215 -5.1 miles

and the winner is......

CA-99/I-5+US-50  - 9.2 miles

Hope I didn't miss any....

--jpm

What about surface route multiplex length?   There some that are still kind of lengthy like CA 108/120. 

[DTComposer]

Wouldn't it be a freeway portion of a CA-1/US-101 concurrency?  Off the top of my head, the concurrency between La Conchita and Goleta would be the longest.

That gap in CA 1 -- actually between La Conchita and Las Cruces -- isn't actually defined as Route 1, just 101.  There are no CA 1 reassurance shields or trailblazers between those two points.  The other two functional coincidences -- between Pismo Beach and San Luis Obispo and US 101 at the Presidio in S.F. north to Mill Valley -- are dual-signed as US 101/CA 1.  And seeing as there's no official recognition of the CA 1/US 101 junction at Rice Avenue east of Oxnard, there are no roadside CA 1 reassurance shields on US 101 along that stretch from there to north of Ventura -- despite a few sporadic CA 1 shields on BGS's.   Not surprising, considering the La Conchita segment of CA 1 is only recognized and "trailblazed" from US 101 via smallish roadside green signs.  Personally, I consider that there are 2 1/2 concurrencies -- the longstanding signed ones in SLO County and over the GG Bridge; the "half" one would be between Oxnard and north of CA 33 in Ventura -- and only because of that occasional overhead BGS signage.   Between La Conchita and Las Cruces CA 1 doesn't get a peep in the way of recognition or signage.  Coincidentally, that "half" is located in Caltrans' District 7 (Ventura and L.A. counties); the long "unstated" stretch south of Las Cruces is in District 5 (Central Coast).  Different districts long have had different sign policies -- although neither of the two relevant here has an exemplary track record for accuracy and thoroughness.   Nonetheless, in a carryover from the old LRN/SSR days, there's only one legal route definition for any of the concurrencies, signed or not -- and it is always US 101. 

Speaking of the GG Bridge, isn't it technically devoid of both US 101 and CA 1?

Correct, that's owned by the City of San Francisco.

Sorta. It's owned by a special district consisting each of elected and appointed officials from San Francisco as well as Marin, Napa, Sonoma, Mendocino, and Del Norte Counties. The district also runs some ferry and local transit services.

[jpm]

What would be the longest freeway concurrency (concurrency between two full-length freeways)?

I can only think of CA-60 and I-215 for all that distance it covers in Riverside. Or CA-60 and CA-57 in Diamond Bar. Haha, what's up with the IE and combining freeways?

Let's see what Google Maps sez:
CA-57/CA-60 - 1.6 miles (it always seemed longer than that...)
CA-22/I-405 - 2 miles (again, seems longer probably because of so much traffic on the San Diego Freeway)
I-80/I-580 - 3.8 miles
CA-60/I-215 -5.1 miles

and the winner is......

CA-99/I-5+US-50  - 9.2 miles

Hope I didn't miss any....

--jpm

What about surface route multiplex length?   There some that are still kind of lengthy like CA 108/120.

The longest I could find were:
CA-70/CA-89 33.8 miles (NE Calif)
CA-108/CA-120 25 miles (Sierra Foothills)
CA-139/CA-299 21.6 miles (NE Calif)
CA-78/CA-86 19.4 miles (Imperial county)

Don't even ask me about US 101/CA-1 - that's too hard to figure out.

--jpm

[pderocco]

Hi everyone.
Some trivial pursuit:
I was wondering that California highway has the most concurrencies with other highways?

The most I can figure out is 7 with CA-89 as it wanders through Northeast California.  It runs along with the following highways:
CA-44
CA-36
CA-70
CA-49
I-80
US 50
CA-88

CA-33 also has 7 (from North - South):
CA-140
CA-152
I-5
CA-198
CA-58
CA-166
CA-150

CA-49 has 6:

CA-89
CA-20
CA-88
CA-108
CA-120
CA-140

Are there any other highways with this many?

49 multiplexed with 4 in Angels Camp until about ten years ago. It probably also multiplexed with 193 through Auburn many years ago, and is incorrectly shown that way by Google.

The 49/89 multiplex is interesting because it's an opposite way multiplex: CA-49N = CA-89S and vice versa.

[pderocco]

99 is pretty up there too; 58, 59, 140, 120, 4, 50, 5 and 162.

It doesn't really multiplex with US-50 and I-5 in Sacramento, there is a break in 99 through there. On the other hand, you left out 12 in Lodi. It's fully signed, including a reassurance sign on SB 99. So that makes it a 7.

[dbz77]

Of course, technically California highways have no concurrences since they're not legislatively allowed.

Since when were concurrencies not allowed?

This would imply US 6 never really was concurrent with US 395 (or was it the other way around?) despite the highway markers and road maps.

Even if you count the multiple CA-1 sections as one, US-101 has 12 concurrences. Also formerly had CA-170.

what happened with CA-170?

[Max Rockatansky]

Of course, technically California highways have no concurrences since they're not legislatively allowed.

Since when were concurrencies not allowed?

This would imply US 6 never really was concurrent with US 395 (or was it the other way around?) despite the highway markers and road maps.

Even if you count the multiple CA-1 sections as one, US-101 has 12 concurrences. Also formerly had CA-170.

what happened with CA-170?

CA 170 had a segment south through Cahuenga Pass on Highland Avenue, look at the 1964 State Highway Map on the link below:

https://www.gribblenation.org/2019/05/hollywood-freeway-california-state.html?m=1

[TheStranger]

Of course, technically California highways have no concurrences since they're not legislatively allowed.

Since when were concurrencies not allowed?

This would imply US 6 never really was concurrent with US 395 (or was it the other way around?) despite the highway markers and road maps.

This is a bit of a technical explanation:

Since 1964, legislative definitions of routes include breaks for where there are concurrencies, in which the official route on that segment is only one of the two or more numbers on that stretch.

So for instance, in Menlo Park, the stretch of Bayshore Freeway that carries both US 101 and Route 84 is legislatively only Route 84.

But that of course doesn't mean that the concurrency itself doesn't exist per se, just that it isn't codified in the route definitions.

Even if you count the multiple CA-1 sections as one, US-101 has 12 concurrences. Also formerly had CA-170.

what happened with CA-170?

Route 170 along Highland Avenue in Hollywood was decommissioned several years ago.  It wasn't signed on the Hollywood Freeway/US 101 between Route 134 and the Highland exit, but was signed a bit along Highland ca. 2010. 

(In the 1960s-1970s, a 170 Laurel Canyon Freeway extension was proposed from just south of the 134/101/170 junction towards LAX, with the only segment built being the La Cienega Boulevard freeway segment from Slauson Avenue northwards)