Interstate 780 and path of California State Route 141

After crossing Carquinez Straight into Solano County via the Benicia-Martinez Bridge on Interstate 680 I made a western turn on I-780 towards mainline I-80.

Interstate 780 is a 7 mile freeway which runs from I-680 in Benicia westward to I-80 in Vallejo. The corridor occupied by I-780 by a 1935 extension of Legislative Route Number 74. Contrary to what I've read elsewhere I have never been able to find a State Highway Map from 1935 up to the 1964 State Highway indicating that LRN 74 between Vallejo east to Benicia was signed as California State Route 29. The 1963 State Highway Map below does not display CA 29 between US 40 and CA 21 in Benicia.

1963 State Highway Map

The original routing of LRN 74 between CA 21 in Benicia west to US 40 was on Benicia Road from starting from 2nd Street. By the 1964 Highway renumbering the freeway grade replacement of Benicia Road was completed and the route was assigned as part of I-680.

1964 State Highway Map

In 1976 the legislative definition of I-680 was changed to run north to I-80 on what was CA 21. I-680 between Benicia and Vallejo was renumbered to I-780.

CAhighways.org on I-780

The change from I-680 to I-780 can be seen on the 1977 State Highway Map.

1977 State Highway Map

Heading westbound on I-780 the waters of Carquinez Straight are almost immediately apparent.

Access to Benicia Capitol State Historic Park can be obtained from Exit 5 for 2nd Street in Benicia. Benicia was briefly the third California State Capitol from February 1853 to February of 1854 after San Jose and Vallejo. The Benicia State Capitol building is the only pre-Sacramento structure still standing.

Access to Benicia State Park is signed for Exit 3A onto Columbus Parkway.

West of Exit 3A the route of I-780 enters Vallejo.

I-780 terminates at I-80. Traffic for I-80 eastbound must take Exit 1B whereas I-80 westbound traffic must take Exit 1A.

Directly west of I-80 the path of I-780 becomes non-state maintained Curtola Parkway. During the 1964 State Highway renumbering CA 141 was assigned to the former portion of LRN 74 between I-80 and CA 29. At the time CA 141 appears to have used Lemon Street, Benicia Road and Maine Street to connect from I-80/I-680 to CA 29.

By 1966 the implied path of CA 141 to CA 37 appears on the State Highway Map.

1966 State Highway Map

The above proposed extension is interesting since the legislative definition extending CA 141 to CA 37 wasn't defined until 1975.

CAhighways.org on CA 141

The 1967 State Highway Map shows CA 141 on Curtola Parkway.

1967 State Highway Map

CA 141 was deleted by the legislature in 1988 according to CAhighways.org. CA 141 appears to have never been signed in the field as ever on the 1988 State Highway Map is just shown as a legislative route. CA 141 was never completed to CA 37 but the implied path is Mare Island Way.

1988 State Highway Map

Morgan Territory Road

Morgan Territory Road is an approximately 14.7-mile-long roadway mostly located in the Diablo Range of Contra Costa County, California. The roadway is named after settler Jerimah Morgan who established a ranch in the Diablo Range in 1857. Morgan Territory Road was one of several facilities constructed during the Gold Rush era to serve the ranch holdings. The East Bay Regional Park District would acquire 930 acres of Morgan Territory in 1975 in an effort to establish a preserve east of Mount Diablo. The preserve has since been expanded to 5,324 acres. The preserve functionally stunts the development along roadway allowing it to remain surprisingly primitive in a major urban area. Part 1; the history of Morgan Territory Road During the period of early period of American Statehood much of the Diablo Range of Contra Costa County was sparsely developed. Jerimah Morgan acquired 2,000 acres of land east of Mount Diablo in 1856 and established a ranch in 1857. Morgan Territory Road is

The 1915 Fine Gold Creek Bridge (Madera County)

The 1915 Fine Gold Creek Bridge is an early era arch concrete structure found alongside modern Madera County Road 200. The structure was modeled as a smaller scale of the 1905 Pollasky Bridge (still in ruins at the San Joaquin River) and was one of many early twentieth century improvements to what was then known as the Fresno-Fresno Flats Road. The 1915-era bridge was replaced with a modernized concrete span during 1947 but was never demolished. The original concrete structure can be still found sitting in the brush north of the 2023 Fine Gold Creek Bridge. Part 1; the history of the 1915 Fine Gold Creek Bridge The 1915 Fine Gold Creek Bridge lies near the site of the former mining community of Fine Gold. Mining claims were staked at Fine Gold during the Mariposa War during 1850. The community was never very large but became a stopping point on the stage road between the original Fresno County seat at Millerton and Fresno Flats (now Oakhurst). The stage road eventually bypas

Old Sonoma Road

Old Sonoma Road is an approximately five-mile highway located in the Mayacamas Mountains of western Napa County. The roadway is part of the original stage road which connected Napa Valley west to Mission San Francisco Solano as part of El Camino Real. Much of Old Sonoma Road was bypassed by the start of the twentieth century by way of Sonoma Highway. A portion of Old Sonoma Road over the 1896 Carneros Creek Bridge (pictured as the blog cover) was adopted as part of Legislative Route Number 8 upon voter approval of the 1909 First State Highway Bond Act. The 1896 Carneros Creek Bridge served as a segment of California State Route 37 and California State Route 12 from 1934 through 1954. Part 1; the history of Old Sonoma Road Old Sonoma Road has origins tied to the formation of Mission San Francisco Solano and the Spanish iteration of El Camino Real. Mission San Francisco Solano was founded as the last and most northern Spanish Mission of Alta California on July 4, 1823. The new M

DJ Jay said…

There was a time in the late-1970s to mid-1980s where CA 141 signs were actually on the streets, but only as "directional" continuances.
For example, a CA 141 with straight-ahead arrow was erroneously erected on a little street-island at the five-way intersection of Solano Avenue, Maine Street, Amador Street and Benicia Road. The straight-arrow sign for CA 141 led commuters to believe 141 continued west on Solano Avenue, not west on Maine Street. (It should've been a diagonal-right arrow, pointing to Maine Street westbound.)
A proper CA 141 sign posting was south on Benicia Road, with a directional sign attached, instructing drivers the continuance of 141 onto Lemon Street toward the western terminus of I-780. The other correct postings of CA 141 were on Sonoma Boulevard/CA 29, where CA 141 signs were posted with proper arrows to lead the driver onto Maine Street eastbound (the South CA 29 signs leading drivers to CA 141 also added a "<-- Benicia" sign underneath the CA 141/left turn arrow signages.
Those CA 141 signs I recall seeing on my travels in Vallejo, where I was born/raised.
Oddly, no CA 141 signs were ever posted along its route, itself. I always thought that was odd.

3:14 AM