Interstate 780

{{short description|Interstate Highway in California}} {{Use mdy dates|date=December 2022}} {{Use American English|date=December 2022}} {{Infobox road |state=CA |type=I |route=780 |section=623 |map={{maplink-road|from=Interstate 780.map}} |map_custom=yes |map_notes=I-780 highlighted in red |length_mi=6.5 |length_ref=<ref name="FHWA">{{cite web |date=December 31, 2021 |title=Table 2: Auxiliary Routes of the Dwight D. Eisenhower National System Of Interstate and Defense Highways |url=https://www.fhwa.dot.gov/planning/national_highway_system/interstate_highway_system/routefinder/table02.cfm |access-date=July 13, 2022 |work=FHWA Route Log and Finder List |publisher=Federal Highway Administration |archive-date=February 13, 2023 |archive-url=https://web.archive.org/web/20230213083642/https://www.fhwa.dot.gov/planning/national_highway_system/interstate_highway_system/routefinder/table02.cfm |url-status=live }}</ref> |established=1973-1976 |history=State highway in 1935; Interstate (as I-680) in 1955; renumbered I-780 in 1973–76 |spur_type=I |spur_of=80 |direction_a=West |terminus_a={{jct|state=CA|I|80}} in Vallejo |direction_b=East |terminus_b={{jct|state=CA|I|680}} in Benicia |counties=Solano |previous_type=I |previous_route=710 |next_type=I |next_route=805 }} thumb|Western end of Interstate 780 at the interchange with Interstate 80 in Vallejo '''Interstate 780''' ('''I-780''') is an east–west auxiliary Interstate Highway in the San Francisco Bay Area of Northern California. It runs from the intersection of Curtola Parkway and Lemon Street in Vallejo east to I-680 just north of the Benicia–Martinez Bridge in Benicia. It closely parallels the Carquinez Strait for its entire route. Originally, this segment was part of I-680 before that Interstate was extended and rerouted to Fairfield. The city-maintained '''Curtola Parkway''' continues west to State Route 29 (SR 29) in Vallejo.

==Route description== The entirety of I-780 is defined in section 623 of the California Streets and Highways Code as '''Route 780''', and that the highway is from "Route 680 at Benicia to Route 80 in Vallejo".<ref name="CSHC623">{{Cite web|url=https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=SHC&sectionNum=623.|title=Section 623|work=California Streets and Highways Code|publisher=California Office of Legislative Counsel|location=Sacramento|access-date=August 25, 2025}}</ref> This definition roughly corresponds with the Federal Highway Administration (FHWA)'s route logs of I-780.<ref name=fhwa-nhs /><ref name="FHWA"/>

The I-780 state-maintained freeway actually begins at Lemon Street and Curtola Parkway, quickly crossing underneath I-80 at a cloverleaf interchange. The freeway passes through parts of unincorporated Solano County, then heads southeast along the Benicia State Recreation Area (a marsh). It then bypasses downtown Benicia through the hills to the north. I-780 ends at I-680 at the north end of the Benicia–Martinez Bridge, with I-680 heading south through the East Bay to San Jose.<ref name=maps>Google Maps street maps and USGS topographic maps, accessed February 2008 via [http://mapper.acme.com/ ACME Mapper] {{Webarchive|url=https://web.archive.org/web/20080102075829/http://mapper.acme.com/ |date=January 2, 2008 }}</ref>

I-780 is part of the California Freeway and Expressway System<ref name="cafes">{{CAFESystem}}</ref> and, as with every Interstate Highway, is part of the National Highway System,<ref name=fhwa-nhs>{{FHWA NHS map|region=sanfrancisco|access-date=July 23, 2017}}</ref> a network of highways that are considered essential to the country's economy, defense, and mobility by the Federal Highway Administration (FHWA).<ref name=NHS-FHWA>{{FHWA NHS}}</ref>

==History== By 1914, a paved county road connected Vallejo and Benicia north of the Carquinez Strait,<ref name="grinnon041914">{{cite news | title=Road News from All Over The State | work=Oakland Tribune | date=15 May 1914 | last=Grinnon | first=Edmund | quote=Vallejo to Benicia. paved road; to Napa, paved to county line, rough to one mile beyond city of Napa;}}</ref> following the present Maine Street, Benicia Road, Columbus Parkway, and K Street.<ref name=bluebook>Official Automobile Blue Book, [https://books.google.com/books?id=Mt0NAAAAYAAJ Volume Eight], 1917, pp. 146, 180</ref> Although state highways were designated to Benicia in 1910 (Legislative Route (LRN) 7, now I-680) and Vallejo in 1931 (LRN 74, now SR 29), this connection was not added until 1935, when LRN 74 (an unsigned designation) was extended east from Vallejo to Benicia and north along former LRN 7 to Fairfield.<ref>{{cite CAstat|year=1935|ch=274|p=959, 281}}: "Route 74 is from a point on Route 8 near the Napa Y to Cordelia via Vallejo and Benicia."</ref> (A short spur connecting Vallejo to the Carquinez Bridge was added to LRN 74 in 1937.<ref>{{cite CAstat|year=1937|ch=219|p=515}}: "Route 74 is from a point on Route 8 near the Napa Y to Cordelia via Vallejo and Benicia, including a connection from Vallejo to Route 7 near the Carquinez Bridge."</ref>) LRN 74 initially entered Benicia on K Street and left on East 5th Street, making several turns in between.<ref name=bluebook/><ref>United States Geological Survey, [https://web.archive.org/web/20110719150325/http://sunsite2.berkeley.edu/lizardtech/iserv/calcrgn?cat=histopo&item=brk00000052_10a.sid&wid=600&hei=500&style=generic%2Fview.xsl&plugin=true Carquinez Strait] (scale 1:62500), 1940</ref> Two realignments were built in the 1940s, reducing the number of turns to one, at the corner of L and East 2nd streets.<ref name=NBI>National Bridge Inventory database, 2006: the bridges on East Second Street north of Benicia are dated 1942 and 1944; the pedestrian bridge over Curtola Parkway is dated 1987</ref><ref>United States Geological Survey, [https://web.archive.org/web/20110719150401/http://sunsite2.berkeley.edu/lizardtech/iserv/calcrgn?cat=histopo&item=brk00000275_10a.sid&wid=600&hei=500&style=generic%2Fview.xsl&plugin=true Benicia] (scale 1:24000), 1950</ref>

On September 15, 1955, the Bureau of Public Roads approved the Interstate Highway System spurs and connections in urban areas. Among these was a loop around the San Francisco Bay, soon numbered I-280 and I-680. The east half (I-680) incorporated a number of existing legislative routes, including LRN 69, LRN 108, LRN 107, LRN 75, and LRN 74, crossing the Carquinez Strait on the proposed Benicia–Martinez Bridge and ending at I-80 near downtown Vallejo.<ref>Bureau of Public Roads, General Location of National System of Interstate Highways, 1955: San Francisco</ref><ref name=selected>California Department of Transportation, [http://www.dot.ca.gov/hq/tsip/hseb/products/state_highway_routes_selected_information_1995_revised.pdf State Highway Routes: Selected Information] {{Webarchive|url=https://web.archive.org/web/20070316231706/http://www.dot.ca.gov/hq/tsip/HSEB/products/state_highway_routes_selected_information_1995_revised.pdf |date=March 16, 2007 }}, 1994 with 1995 revisions, pp. 342, 348</ref> The first piece of this freeway north of the Carquinez Strait was at the I-80 cloverleaf interchange, built in the late 1950s when I-80 was upgraded through Vallejo. This was an extremely short roadway, beginning at Lemon Street, crossing under I-80 and Laurel Street and ending at Reis Avenue and Cedar Street.<ref name=bridgelog>{{Caltrans bridgelog|date=July 2007}}</ref><ref>United States Geological Survey, [https://web.archive.org/web/20110719150409/http://sunsite2.berkeley.edu/lizardtech/iserv/calcrgn?cat=histopo&item=brk00000276_10a.sid&wid=600&hei=500&style=generic%2Fview.xsl&plugin=true Benicia] (scale 1:24000), 1959</ref> In about 1960, it was extended east to the old highway (Columbus Parkway) between the cities and was completed to the new bridge in about 1962, the year the bridge opened.<ref name=bridgelog/>

{{infobox road small |state=CA |type=CA |route=141 |location=Vallejo |formed=1964 |deleted=1988 }} In the 1964 state highway renumbering, the legislative designation of the completed Vallejo–Benicia freeway was changed from LRN 74 to LRN 680, reflecting its Interstate designation. The short piece of nonfreeway in Vallejo, extending west from I-80 to SR 29, became '''State Route 141''' ('''SR 141''').<ref name=law-renumbering>{{cite CAstat|year=1963|ch=385|p=1182, 1189}}: "Route 141 is from Route 80 to Route 29 in Vallejo." "Route 680 is from Route 280 in San Jose to Route 80 in Vallejo passing near Warm Springs, Mission San Jose, Scotts Corners and Sunol, and via Walnut Creek and Benicia."</ref> This route followed Benicia Road and Maine Street, the same alignment the state highway had always taken; it initially connected with I-780 via Lemon Street<ref>Division of Highways, [http://cahighways.org/maps/1963sfbay.jpg San Francisco and Vicinity] {{Webarchive|url=https://web.archive.org/web/20071231013131/http://www.cahighways.org/maps/1963sfbay.jpg |date=December 31, 2007 }}, 1963</ref> but later followed Benicia Road from I-80 north of I-780. In 1975, a proposed (and never constructed) extension west and north to SR 37 east of the Napa River was added to LRN 141.<ref>California Department of Transportation, [http://cahighways.org/maps/1986sfbay.jpg San Francisco and Vicinity] {{Webarchive|url=https://web.archive.org/web/20071231013133/http://www.cahighways.org/maps/1986sfbay.jpg |date=December 31, 2007 }}, 1986</ref><ref>{{cite CAstat|year=1975|ch=1078|p=2638}}: "Route 141 is the westerly extension of Route 680 from Route 80 to Route 37."</ref> The route was to be the '''Waterfront Freeway''', scaled down to a boulevard in 1974.<ref>Vallejo Times Herald, No Freeway for Waterfront Blvd, April 25, 1974</ref><ref>Vallejo Times Herald, Vallejo Approves Measure to Speed Waterfront Boulevard Construction, August 20, 1974</ref>

The FHWA approved a relocation of I-680 onto the SR 21 freeway between Benicia and Fairfield in July 1973. To keep the route to Vallejo in the Interstate system, it was renumbered I-780;<ref name=selected/> the corresponding legislative changes were made in 1976.<ref>{{cite CAstat|year=1976|ch=1354|p=6178}}: "Route 780 is from Route 680 at Benicia to Route 80 in Vallejo."</ref> As part of the project to construct a new northbound Benicia–Martinez Bridge, the I-680/I-780 interchange was rebuilt;{{When|date=February 2011}} the new span opened in August 2007.<ref>Metropolitan Transportation Commission, [http://www.mtc.ca.gov/news/press_releases/rel418.htm Rep. George Miller to Keynote Celebrations for Completion of New Benicia-Martinez Bridge]{{dead link|date=January 2013}}, August 23, 2007</ref> LRN 141 was deleted from the state highway system in 1988,<ref>{{cite CAstat|year=1988|ch=106|p=443}}</ref> soon after the city of Vallejo constructed Curtola Parkway over (replacing Maryland Street) just to the south, directly connecting I-780 with a surface road to SR 29.<ref name=NBI/>

==Exit list== Mileage was measured from east-to-west based on the alignment of LRN 680 as it existed at that time. Exit numbers were still assigned the conventional west-to-east ascension.<ref name=calnexus/> {{CAinttop|exit |length_ref=<ref name=calnexus/><ref name=trucklist>{{Caltrans trucklist}}</ref> |exit_ref=<ref name=calnexus>{{cite web |date=March 17, 2020 |publisher=California Department of Transportation |work=California Numbered Exit Uniform System |url=https://dot.ca.gov/-/media/dot-media/programs/safety-programs/documents/exit/calnexus-i-780-03-2020-a11y.pdf |title=Interstate 780 Freeway Interchanges |access-date=October 17, 2020 |archive-date=October 18, 2020 |archive-url=https://web.archive.org/web/20201018203403/https://dot.ca.gov/-/media/dot-media/programs/safety-programs/documents/exit/calnexus-i-780-03-2020-a11y.pdf |url-status=live }}</ref> |county=Solano }} {{CAint|exit |location=Vallejo |lspan=7 |mile=6.75 |mspan=2 |exit=— |road=Curtola Parkway |notes=Continuation beyond Lemon Street }} {{CAint|exit |mile=none |exit=— |road=Lemon Street |notes=Western terminus; at-grade intersection }} {{CAint|exit |mile=6.70 |mspan=2 |exit=1A |road={{Jct|state=CA|I|80|dir1=west|city1=San Francisco}} |notes=I-80 exit 30A |nspan=2 }} {{CAint|exit |mile=none |exit=1B |road={{Jct|state=CA|I|80|dir1=east|city1=Sacramento}} |notes=none }} {{CAint|exit |mile=6.58 |mspan=2 |exit=1C |espan=2 |road=Laurel Street |notes=Eastbound signage }} {{CAint |mile=none |road=Cedar Street |notes=Westbound signage }} {{CAint|exit |mile=5.51 |exit=1D |road=Glen Cove Road |notes= }} {{CAint|exit |location=Benicia |lspan=7 |mile=4.28 |exit=3A |road=Columbus Parkway |notes=Serves Benicia State Recreation Area }} {{CAint|exit |mile=3.51 |exit=3B |road=Military West |notes= }} {{CAint|exit |mile=3.32 |exit=4 |road=Southampton Road |notes= }} {{CAint|exit |mile=1.52 |exit=5 |road=East Second Street – Central Benicia |notes= }} {{CAint|exit |mile=1.09 |exit=6 |road=East Fifth Street |notes= }} {{CAint|exit |mile=0.00 |mspan=2 |exit=7A |road={{Jct|state=CA|I|680|dir1=north|city1=Fairfield|city2=Sacramento}} |notes=Eastern terminus; I-680 exit 58A; tri-stack interchange |nspan=2 }} {{CAint|exit |mile=none |exit=7B |road={{Jct|state=CA|I|680|dir1=south|city1=Martinez|city2=San Jose}} |notes=none }} {{Jctbtm|col=6}}

==See also== *{{portal-inline|California Roads}} *{{portal-inline|San Francisco Bay Area}}

==References== {{Reflist|30em}}

==External links== {{Attached KML|display=title,inline}} {{commonscat}} {{CASR external links|I|780}} *[http://www.cahighways.org/505-805.html#780 California Highways: Interstate 780] *[http://www.aaroads.com/california/i-780_ca.html California @ AARoads.com - I-780]

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