Interstate 780 and California State Route 141

[Max Rockatansky]

The last highway I drove in the first of two recent Bay Area trips was I-780 from I-680 west to I-80.  I-780 is something of an oddity in that it was part of LRN 74 but was never signed between CA 29 in Vallejo east to CA 21 in Benicia.  LRN 74 between US 40 and CA 21 was upgraded to freeway standards by 1964 and was initially signed as I-680.  The I-680 signage was swapped out for I-780 by 1976 when the former took over the alignment of CA 21 north of the Benicia-Martinez Bridge.  I also looked into CA 141 which was carved out of LRN 74 between US 40 west to CA 29.  CA 141 appears to have initially used Lemon Street, Benicia Road and Maine Street before being shifted to Curtola Parkway.

https://surewhynotnow.blogspot.com/2019/02/interstate-780-and-path-of-california.html

My photo set for I-780 can be found below:

https://flic.kr/s/aHsmvmpsUf

[sparker]

The last highway I drove in the first of two recent Bay Area trips was I-780 from I-680 west to I-80.  I-780 is something of an oddity in that it was part of LRN 74 but was never signed between CA 29 in Vallejo east to CA 21 in Benicia.  LRN 74 between US 40 and CA 21 was upgraded to freeway standards by 1964 and was initially signed as I-680.  The I-680 signage was swapped out for I-780 by 1976 when the former took over the alignment of CA 21 north of the Benicia-Martinez Bridge.  I also looked into CA 141 which was carved out of LRN 74 between US 40 west to CA 29.  CA 141 appears to have initially used Lemon Street, Benicia Road and Maine Street before being shifted to Curtola Parkway.

https://surewhynotnow.blogspot.com/2019/02/interstate-780-and-path-of-california.html

My photo set for I-780 can be found below:

https://flic.kr/s/aHsmvmpsUf

LRN 74 was unusual in that it was U-shaped, consisting of SSR 29 from SSR 12/LRN 8 at Napa Junction south to the intersection of present CA 29 and Maine Street in Vallejo; there it split into the main stem which extended east on Maine to Benicia-Vallejo Road, then utilized that into Benicia; the surface street was never signed as a SSR prior to 1964.  However, SSR 29 south from the intersection in Vallejo to I-80 just north of the Carquinez Bridge(s) was a LRN 74 spur.  Once in Benicia, it spawned another spur to the ferry terminal to Martinez, across the Carquinez Strait; this, and the remainder of LRN 74 north to Cordelia Junction (old US 40/LRN 7) were signed as part of SSR 21, which utilized the ferry to get to its southern section in Contra Costa and Alameda counties.  By late 1962 the initial section of I-680 from the present I-80/780 interchange in Vallejo east toward Benicia had opened, and LRN 74 was rerouted over that freeway; two years later CA 141 subsumed the section of LRN 74 between CA 29 and I-80, although the east end had been shunted south to the NW end of (then) I-680, which entailed about a 2-3 block right-angle shunt south of Benicia-Vallejo Road.  CA 141 received signage circa 1968; this involved trailblazers and an initial reassurance shield on EB Maine, directional changes where the route shifted to Benicia-Vallejo Road, and I-680 (later 780) trailblazers at the shunt down to the end of that freeway about a quarter-mile west of I-80.  The sole CA 141 indication WB was at the stub-end of the I-680/780 freeway, which was originally planned to continue on to CA 37 via Mare Island.  That freeway routing was deleted from the system in 1976 along with a batch of others statewide as part of then-Caltrans director Adriana Gianturco's orders to slash as much urban proposed freeway mileage as possible (with legislative concurrence).  Signage remained on the surface segment of CA 141 until that too was relinquished circa 1982.  One "straggler" CA 141 sign remained at the Maine/B-V Road intersection until about 1989, but it disappeared about that time. 

Actually, I'm surprised that CA 29 between I-80 and CA 37 hasn't been relinquished, since most through I-80 traffic to northward CA 29 simply uses the CA 37 freeway over to the CA 29 alignment rather than schlep down Sonoma Blvd. and its multitude of traffic lights in downtown Vallejo.  A likely explanation is that Vallejo, ever in dire financial straits, simply has declined to assume maintenance of the street.  BTW, the divided Curtola Parkway was never a part of CA 141 but simply a city-maintained trajectory extension of the I-780 freeway -- although it was cobbled up along the ROW that had been acquired for the 141 freeway prior to its 1976 deletion. 

[TheStranger]

I still remember as recently as the early 2000s when Route 37 from I-80 to Mare Island had a freeway gap between Route 29 and the Marine World exit - when Route 141 was still an active proposed freeway corridor, was the upgrading of that part of 37 not on the books at the time?   

[Max Rockatansky]

Regarding Curtola Parkway there is definitely a shift in the highway maps that indicate that there was some some change of state maintenance south from Benicia Road between 80 and 29.  What I'm finding interesting is hearing about 141 actually being signed in field.  Granted maps are just maps but I've found them to be a somewhat accurate method of narrowing down when new State Routed were signed post 1964. 

What sucks in retrospect was that I didn't realize 141 was even there until I got back from my trip.  Had I known beforehand I would kept on going to 29. 

[bing101]

I still remember as recently as the early 2000s when Route 37 from I-80 to Mare Island had a freeway gap between Route 29 and the Marine World exit - when Route 141 was still an active proposed freeway corridor, was the upgrading of that part of 37 not on the books at the time?

Yes I remember that the CA-37 gap was then known as Marine World Parkway until the freeway gap between I-80 to Mare Island was completed by 2005.

Also I remember that former CA-37 alignment Called Marine World Parkway was later renamed as Louis Brown Drive though.

[sparker]

Apparently the relinquishment of CA 141 occurred in 1988 rather than around 1982 as I had earlier surmised.  The Curtola Parkway's construction began in 1988 as well, with the facility opening in late 1989.  I had always been curious about whether that parkway was itself simply a relocation of CA 141, so after I moved from Roseville to Windsor (Sonoma County) back in the summer of 1990 I drove over to Vallejo and over the Curtola specifically looking for Caltrans' signature white milepost paddles; there were none to be found west of I-80 in either direction.  Apparently Caltrans ceded the ROW for the cancelled CA 141 freeway to the City of Vallejo, which constructed the parkway itself; it was part of an overall project to upgrade the city's waterfront (including the S.F. ferry terminal).  Since there was a direct extension of the parkway from Sonoma Blvd./CA 29 west to that waterfront, the parkway was intended to directly convey traffic -- and potential tourists -- from both I-780 and I-80 to the revamped waterfront -- as well as provide improved access from Benicia and environs to the ferry terminal.