Interstate 680 (California)

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Interstate 680

I-680 highlighted in red
Route information
Auxiliary route of I-80
Maintained by Caltrans
Length70.52 mi[1] (113.49 km)
HistoryState highway in 1933; Interstate in 1955
Tourist
routes		California Scenic State.svg I-680 between Mission Boulevard (SR 238) in Fremont to SR 24 in Walnut Creek[2]
NHSEntire route
Major junctions
South end I-280 / US 101 in San Jose
Major intersections
North end I-80 / SR 12 in Fairfield
Location
CountryUnited States
StateCalifornia
CountiesSanta Clara, Alameda, Contra Costa, Solano
Highway system
← I-605→ I-710

Interstate 680 (I-680) is a north–south auxiliary Interstate Highway in Northern California. It curves around the eastern cities of the San Francisco Bay Area from San Jose to I-80 at Fairfield, bypassing cities along the eastern shore of San Francisco Bay such as Oakland and Richmond while serving others more inland such as Pleasanton and Concord.

Built in the 1920s and designated in 1955, I-680 begins at a junction with I-280 and US Route 101 (US 101/Bayshore Freeway) and heads northeast and north-northwest through the northeast part of San Jose. After passing State Route 237 (SR 237) in Milpitas and SR 262 in Fremont, I-680 abruptly turns northeast (where a connection to a SR 238 freeway was planned) and enters the hills and valleys of the California Coast Ranges. The highway crosses over Mission Pass, also known as the Sunol Grade, and descends into the Sunol Valley, where it meets SR 84 near Sunol. From Sunol, I-680 again heads north-northwesterly through valleys, including the San Ramon Valley, along the Calaveras Fault. Junctions along this portion include I-580 in Dublin and SR 24 in Walnut Creek. Beyond the latter interchange, a three-way directional junction with the SR 24 freeway west to Oakland, I-680 heads north into Pleasant Hill, where SR 242 splits and I-680 again heads northwesterly. After the junction with SR 4 in Martinez, the highway crosses the Carquinez Strait on the Benicia–Martinez Bridge, immediately meeting the east end of I-780 on the Benicia end. The remainder of I-680, from Benicia to I-80 at Fairfield, lies between a hilly area to the west representing the southwestern tip of the Vaca Mountains, and a marshy area (along the Suisun Bay and Cordelia Slough) to the east.[3]

Route description

Southbound at SR 4, with Mount Diablo on the left
Pleasant Hill, Concord, Martinez, and Vallejo aerial looking north, with I-680, the EBMUD Trail, the Walnut Creek, and the bridges over the Carquinez Strait. I-680 roughly parallels the Walnut Creek (the orange channel) from Walnut Creek to the Carquinez Strait.

The route begins at US 101 at the Joe Colla Interchange, where it acts as a continuation of I-280 eastward.[4] From here, it begins its journey northward through San Jose, where it meets the Capitol Expressway, signed as County Route G21 (CR G21), about a mile (1.6 km) northeast of I-680's southern terminus.[5] The next exit northbound is SR 130, which is also known as Alum Rock Avenue, unsigned at the intersection.[6][7] As it continues through Santa Clara County, it meets numerous local roads before interchanging with the Montague Expressway (CR G4). Here, it exits San Jose and enters the city of Milpitas, where it meets SR 237, often referred to as Calaveras Boulevard. After one more intersection, I-680 exits Santa Clara County and enters Alameda County.[5]

In Alameda County, the freeway begins in the city of Fremont, where it intersects SR 262, which was unsigned until 2000. Continuing through the city, it meets Mission Boulevard at SR 238 before exiting the city. Prior to 2002, two ghost ramps existed here, remains of an abandoned freeway project replacing Mission Boulevard.[5] Amid Alameda County, it abruptly turns northeastward and enters a hilly area, where it crosses over Mission Pass, and descends into the Sunol Valley, where it runs concurrently with SR 84 for a short while. Afterward, it enters Pleasanton and intersects with I-580, currently California's longest auxiliary Interstate providing access to Oakland and the Central Valley. It enters Dublin for a short segment before exiting the county and entering Contra Costa County.[4][5]

Upon entering Contra Costa County, the route meets numerous local roads through the cities of San Ramon, Danville, and Alamo before entering Walnut Creek, where it meets SR 24.[5] I-680 then enters Pleasant Hill for a short time and Concord, where it meets SR 242. Upon exiting Concord, it meets SR 4. It then enters Martinez, where it follows the Benicia–Martinez Bridge over the Carquinez Strait, on which the route crosses the county line and enters Benicia in Solano County.[4][5][8] On the Benicia–Martinez Bridge, I-680 northbound is tolled, while I-680 southbound is free. In Benicia, I-680 interchanges with I-780. It then exits the city and, after passing through rural areas, routing parallel to the San Joaquin Delta, it enters Fairfield, where it meets I-80, which is the route's northern terminus.[4]

In the wake of the September 11 attacks, a US flag was painted on a large piece of concrete on a hill along the Sunol Grade. It stayed there for nine years before the California Department of Transportation (Caltrans) painted it over, as the mural had been painted on without authorization.[9] Due to this action being taken shortly before July 4, 2010, and also due to the mural's fame, this was met with controversy. The flag was replaced shortly later.

Of the above names, only the name Sinclair Freeway for its designated portion usually appears on maps, and the other portions on maps are always unnamed, referred to as simply I-680.[8]

I-680 is part of the California Freeway and Expressway System[10] and is part of the National Highway System,[11] a network of highways that are considered essential to the country's economy, defense, and mobility by the Federal Highway Administration (FHWA).[12] I-680 is eligible to be included in the State Scenic Highway System from the Santa Clara–Alameda county line to SR 24 in Walnut Creek[13] but is only a scenic route from Mission Boulevard to the Contra Costa county line and from the Alameda county line to SR 24;[2] this means that those portions are substantial sections of highway passing through a "memorable landscape" with no "visual intrusions", where the potential designation has gained popular favor with the community.[14]

Tolls

Express lanes

There are two sections of High-occupancy toll (HOT) lanes along I-680. The 14-mile (23 km) southbound HOT lane along I-680 between SR 84 in Alameda County and through the Sunol Grade to SR 237 in Santa Clara County opened on September 20, 2010.[15] The northbound HOT lane along the same stretch opened in October 2020 but initially as high-occupancy vehicle (HOV) lanes; tolling was halted on this segment of I-680 due to the COVID-19 pandemic and will be resumed in fall 2022.[16]

HOT lanes then opened in October 2017 in both directions on the portion from slightly south of Alcosta Boulevard near the Alameda–Contra Costa line to Rudgear Road in Walnut Creek.[17] On August 20, 2021, the southbound HOT lanes were extended north from Rudgear Road to Marina Vista Boulevard in Martinez.[18]

As of August 2022, the HOT lanes' hours of operation is weekdays between 5:00 am and 8:00 pm. Solo drivers are tolled using a congestion pricing system based on the real-time levels of traffic. Carpools, motorcycles, and clean air vehicles with two or more people are not charged. For clean-air vehicles with a solo driver, 50 percent of the posted toll is charged.[16][19] All tolls are collected using an open road tolling system, and therefore there are no toll booths to receive cash. Each vehicle is required to carry either a FasTrak Flex or CAV (Clean Air Vehicle) transponder, with its switch set to indicate the number of the vehicle's occupants (one, two, three, or more). Solo drivers may also use the FasTrak standard tag without the switch.[16][19] Drivers without any FasTrak tag will be assessed a toll violation regardless of whether they qualified for free.[20]

Benicia–Martinez Bridge

Main article: Benicia–Martinez Bridge § Tolling

Tolls are collected only for northbound traffic on the Benicia–Martinez Bridge. An open road tolling system is also used on the bridge, and they can be paid by either a FasTrak transponder or license plate tolling. The high-occupancy vehicle (HOV) lane leading to the bridge requires a car with three or more people.[21][22]

History

Further information: Interstate 780 § History
Descending from Mission Pass northbound

Historic routing

State Route 21

LocationSan Jose - Fairfield
Existed1934–1976

By the 1920s, a road ran south from Martinez through Walnut Creek, Dublin, Danville, and Sunol to Mission San Jose, where it met Legislative Route 5 (Mission Boulevard, signed over the years as US 48, US 101E, SR 9, and now SR 238). It was not yet paved south of Dublin, where it crossed Mission Pass between the Sunol Valley and the San Francisco Bay basin.[8] The majority of this roadway was added to the state highway system in 1933 as portions of several routes: Route 108 from Mission San Jose to Sunol, Route 107 from Sunol to Walnut Creek, and Route 75 from Walnut Creek to Pleasant Hill.[23][24]

At Martinez, the Martinez–Benicia Ferry took automobiles across the Carquinez Strait to Benicia, where Route 7, one of the original state highways from the 1910 bond issue, led north and northeast past Fairfield toward Sacramento and Oregon.[25] The portion north from Benicia to Fairfield became part of Route 74 in 1935, when Route 7 was realigned to the more direct American Canyon route that is now I-80.[26] None of the aforementioned roads were given state sign route numbers in 1934, when that system was laid out,[27] but, by 1937, they had been numbered SR 21.[28] This route began at the intersection of Warm Springs Boulevard and Brown Road in Warm Springs, where Route 5 and Route 69 (SR 17) split, followed Route 5 along Mission Boulevard to Mission San Jose (this part later became a concurrency with SR 9), and then continued to US 40 (Route 7) at Cordelia. The routing was very close to the present I-680, following such roads as Pleasanton Sunol Road, San Ramon Valley Boulevard, Danville Boulevard, Main Street in Walnut Creek, Contra Costa Boulevard, and Pacheco Boulevard.[29]

The portion of SR 21 between Pleasant Hill and Martinez was finally added to the state highway system in 1949, as a branch of Route 75.[30] The ferry approach in Benicia became a spur of Route 74 in 1947,[31] and, in 1953, it was transferred to Route 75. The same law, effective immediately as an urgency measure, authorized the Department of Public Works to acquire the ferry system, then operated by the city of Martinez, which was planning to shut it down.[32] Ownership was transferred just after midnight on October 6, 1953.[33]

History as an Interstate

1955 map of the planned Interstates in the San Francisco Bay Area. These early plans essentially called for an Interstate loop route that would head south down the San Francisco Peninsula from San Francisco to San Jose, then head north through the eastern cities of the East Bay to Vallejo. This route now basically comprises present-day I-280, I-680, and I-780.

The Bureau of Public Roads approved urban routes of the Interstate Highway System on September 15, 1955, including a loop around the San Francisco Bay, soon numbered I-280 and I-680. The east half (I-680) began at the interchange of US 101 north of Downtown San Jose and followed the Nimitz Freeway (SR 17/Route 69, now I-880) to the split at Warm Springs (the present location of SR 262), SR 21 to Benicia, and Route 74 (no sign route number) to I-80 in Vallejo.[34][35][36] The first piece of I-680 freeway built, other than the preexisting Nimitz Freeway, was in the late 1950s, along the SR 24 overlap between North Main Street in Walnut Creek and Monument Boulevard in Pleasant Hill.[37][38] A southerly extension, bypassing downtown Walnut Creek to South Main Street, opened on March 22, 1960, connecting with the SR 24 freeway to Oakland.[39] In the next decade, the freeway was completed from Vallejo south to SR 238 at Mission San Jose, and the roadway north from Benicia to Fairfield, which became the only remaining piece of SR 21, was also upgraded to freeway standards.[40][41]

In the 1964 state highway renumbering, the legislative designation was changed to Route 680. SR 17 was officially moved to former Route 5 between San Jose and Warm Springs, which had not had a signed designation since the Nimitz Freeway (then I-680) was constructed,[42] but this was instead marked as part of SR 238 (which replaced SR 9 north of Mission San Jose), and SR 17 remained signed along the Nimitz Freeway.[43] This was very short-lived, as the Bureau of Public Roads approved a shift in the south end of I-680 in October 1964.[35] The legislature changed the routes in 1965, swapping Route 17 and Route 680 south of Warm Springs and creating a new SR 262 on the short roadway at Warm Springs where they had overlapped to switch sides.[44][45] However, until I-680 was completed in the early-to-mid 1970s,[40] it remained signed along the Nimitz Freeway, and the old road between San Jose and Warm Springs continued to be marked as SR 238.[41] One more change was made to the routing of I-680: in July 1973, the remainder of SR 21, from Benicia to Fairfield, was added to the Interstate Highway System. This became the new alignment of I-680, and the old route to Vallejo became I-780. The corresponding changes were made by the state legislature in 1976.[46]

Exit list

CountyLocationmi[5][40][47]kmExit[47]DestinationsNotes
Santa ClaraSan Jose0.000.001A
 I-280 north (Sinclair Freeway) – Downtown San Jose		Southern terminus; Joe Colla Interchange; Sinclair Freeway continues west as I-280 north
0.000.001B US 101 (Bayshore Freeway) – Los Angeles, San FranciscoUS 101 north exit 384, south exit 385B
0.390.631AKing RoadSigned as exit 1C southbound
1.191.921BJackson AvenueNorthbound exit and southbound entrance
1.412.271CCapitol Expressway (CR G21)Signed as exit 1D southbound
1.742.802A SR 130 (Alum Rock Avenue)No southbound entrance from eastbound Alum Rock Avenue
2.383.832BMcKee Road
3.846.184Berryessa Road
4.78–
5.07		7.69–
8.16		5Capitol Avenue / Hostetter RoadSigned as exits 5A (Hostetter) and 5B (Capitol) northbound
San Jose–Milpitas line6.179.936Montague Expressway (CR G4) / Landess Avenue
Milpitas—I-680 Sunol Express Lane south endsSouth end of southbound Express Lane
7.6512.318 SR 237 (Calaveras Boulevard) – Central Milpitas
8.5013.689Jacklin Road
Santa Clara–Alameda
county line		Milpitas–Fremont line9.9416.00North end of Sinclair Freeway
10.0616.1910Scott Creek Road – Warm Springs District
AlamedaFremont12.3219.8312
 SR 262 (Mission Boulevard) to I-880		Former SR 21 north
—I-680 Sunol Express Lane north beginsSouth end of northbound Express Lane
13.9522.4514Auto Mall Parkway, Durham Road
15.3124.6415Washington Boulevard – Irvington District
16.3326.2816 SR 238 (Mission Boulevard)Former SR 21 south
17.5428.2318AVargas RoadSigned as exit 18 southbound
​Mission Pass
​18.3729.5618BSheridan RoadSouthbound exit is via exit 20
​19.7731.8220Andrade Road
​—I-680 Sunol Express LanesNorth end of Express Lanes in both directions
​21.1033.9621A
 SR 84 west / Calaveras Road – Sunol, Dumbarton Bridge		South end of SR 84 overlap (northbound only); signed as exit 21 southbound; former SR 21 north
​21.3834.4121B
 SR 84 east – Livermore		North end of SR 84 overlap (northbound only); southbound exit is via a U-turn at exit 21
​21.9835.3722Sunol (Koopman Road)Southbound exit and northbound entrance; former SR 21
Pleasanton24.8039.9125Sunol Boulevard, Castlewood Drive – Pleasanton
26.2942.3126Bernal Avenue – Pleasanton
28.8446.4129Stoneridge Drive
Pleasanton–Dublin line29.6047.6430 I-580 / Dublin Boulevard – Dublin, Oakland, StocktonI-580 exit 44B; Dublin Blvd. not signed northbound; Dublin Blvd. is former US 50. signed as exit 30 southbound
Contra CostaSan Ramon—I-680 Contra Costa County Express LanesSouth end of Express Lanes in both directions
31.4350.5831Alcosta Boulevard – Dublin
34.3055.2034Bollinger Canyon Road
San Ramon–Danville line35.6057.2936Crow Canyon Road – San Ramon
Danville38.1661.4138Sycamore Valley Road
38.9562.6839Diablo Road – Danville
39.5763.6840El Cerro BoulevardSigned as exit 40A southbound
40.1464.6040BEl Pintado RoadNorthbound exit is via exit 40; southbound exit and northbound entrance only
Alamo41.7667.2142Stone Valley RoadSigned as exits 42A (east) and 42B (west)
42.6768.6743Livorna Road
​—I-680 Contra Costa County Express Lane north endsNorth end of northbound Express Lane
Walnut Creek44.0170.8344Rudgear RoadSouthbound exit is via exit 45A
44.5871.7445ASouth Main Street – Walnut CreekNo northbound entrance; former SR 21
45.4373.1145BOlympic Boulevard
45.8873.8446A
 SR 24 west – Lafayette, Oakland		Signed as exit 46 southbound; SR 24 exits 15A-B
46.3674.6146BYgnacio Valley RoadNorthbound exit and southbound entrance
47.1175.8247North Main Street – Walnut CreekFormer SR 21
47.9077.0948Treat Boulevard, Geary RoadSouthbound former Oak Park Boulevard exit
Pleasant Hill48.8678.6349AContra Costa Boulevard – Pleasant HillNorthbound exit and southbound entrance; former SR 21
49.1779.1349BMonument Boulevard, Gregory LaneSingle-point urban interchange; signed as exit 49 southbound; former SR 24 east
Concord–Pleasant Hill line50.2180.8150 SR 242 – Concord, PittsburgNorthbound exit and southbound entrance; SR 242 south exit 1A
50.7481.6651Willow Pass Road, Taylor Boulevard
51.5682.9852Concord Avenue, Burnett Avenue – Pacheco, Concord
​52.8985.1253 SR 4 – Pittsburg, Antioch, Martinez, HerculesSR 4 exits 12B-C
​54.1387.1154Pacheco Boulevard, Arthur RoadFormer SR 21
Martinez—I-680 Contra Costa County Express Lane south beginsNorth end of southbound Express Lane
55.9690.0656Marina Vista Road, Waterfront Road – Martinez
Carquinez Strait57.2292.09Benicia–Martinez Bridge (northbound toll only)
SolanoBenicia58.2793.7858A
 I-780 west – Benicia, Vallejo		Signed as exit 58 southbound; former I-680 north; I-780 exits 7A-B
59.0995.1058BBayshore RoadNorthbound exit and southbound entrance
59.5595.8460Industrial ParkSouthbound exit and northbound entrance
60.9198.0361Lake Herman RoadFormer SR 21 south
​63.11101.5763Parish Road
​65.41105.2765Marshview Road
Fairfield68.11109.6168Gold Hill Road
69.99112.6470Green Valley Road – CordeliaNorthbound exit and southbound entrance
70.48113.4371 I-80 / SR 12 – Fairfield, Sacramento, Napa, San FranciscoNorthern terminus; northbound exit and southbound entrance; signed as exits 71A (east) and 71B (west); I-80 exit 40
1.000 mi = 1.609 km; 1.000 km = 0.621 mi

References

  1. ^ "Table 2: Auxiliary Routes of the Dwight D. Eisenhower National System Of Interstate and Defense Highways". FHWA Route Log and Finder List. Federal Highway Administration. December 31, 2021. Retrieved July 12, 2022.
  2. ^ a b California Department of Transportation (August 2019). "Officially Designated State Scenic Highways and Historic Parkways" (XLSX). Sacramento: California Department of Transportation. Retrieved July 29, 2017.
  3. ^ Google Maps street maps and USGS topographic maps, accessed February 2008 via ACME Mapper
  4. ^ a b c d The United States (Map). National Geographic. October 2006.
  5. ^ a b c d e f g California Department of Transportation. "State Truck Route List". Sacramento: California Department of Transportation. Archived from the original (XLS file) on June 30, 2015. Retrieved June 30, 2015.
  6. ^ "Google Maps". Google Maps. Retrieved 13 April 2018.
  7. ^ "Google Maps". Google Maps. Retrieved 13 April 2018.
  8. ^ a b c Rand McNally & Company, San Francisco and Vicinity, 1927
  9. ^ Berton, Justin (July 3, 2010). "Governor sorry about flag Caltrans painted over". San Francisco Chronicle. Retrieved 20 July 2012.
  10. ^ "Article 2 of Chapter 2 of Division 1". California Streets and Highways Code. Sacramento: California Office of Legislative Counsel. Retrieved February 6, 2019.
  11. ^ Federal Highway Administration (March 25, 2015). National Highway System: California (North) (PDF) (Map). Scale not given. Washington, DC: Federal Highway Administration. Retrieved July 29, 2017.
  12. ^ Natzke, Stefan; Neathery, Mike & Adderly, Kevin (June 20, 2012). "What is the National Highway System?". National Highway System. Washington, DC: Federal Highway Administration. Retrieved July 1, 2012.
  13. ^ "Article 2.5 of Chapter 2 of Division 1". California Streets & Highways Code. Sacramento: California Office of Legislative Counsel. Retrieved February 6, 2019.
  14. ^ California Department of Transportation (2012). Scenic Highway Guidelines (PDF). Sacramento: California Department of Transportation. p. 5. Archived from the original (PDF) on January 5, 2024. Retrieved June 8, 2017.
  15. ^ "I-680 Smart Lane". 680expresslane.org. Retrieved January 26, 2013.
  16. ^ a b c "I-680 Sunol Express Lanes". www.bayareafastrak.org. CalTrans. Retrieved August 14, 2022.
  17. ^ "Commuters confused about new express lanes coming to I-680". KGO-TV. October 5, 2017.
  18. ^ "Southbound I-680 express lane from Martinez to Walnut Creek to begin toll operations Aug. 20". danvillesanramon.com. July 7, 2021.
  19. ^ a b "I-680 Contra Costa Express Lanes". www.bayareafastrak.org. CalTrans. Retrieved August 14, 2022.
  20. ^ "Pay Tolls & Violations". www.bayareafastrak.org. CalTrans. Retrieved August 14, 2022. If you use Bay Area Express Lanes, you must use a FasTrak toll tag, otherwise you will receive a violation notice including toll evasion penalties
  21. ^ "Benicia–Martinez Bridge". www.bayareafastrak.org. CalTrans. Retrieved August 14, 2022.
  22. ^ California Department of Transportation (January 29, 2024). "Programmed or Proposed High-occupancy Vehicle Lanes". California Department of Transportation. Archived from the original on May 29, 2024. Retrieved May 29, 2024.
  23. ^ California State Assembly. An act to amend sections 2, 3 and 5 and to add two sections to be numbered 6 and 7 to an act entitled 'An act to provide for the acquisition of rights of way for and the construction, maintenance... Fiftieth Session of the Legislature. Statutes of California. State of California. Ch. 767, p. 2036.
  24. ^ California State Assembly. An act to establish a Streets and Highways Code, thereby consolidating and revising the law relating to public ways and all appurtenances thereto, and to repeal certain acts and parts of acts specified herein. Fifty-first Session of the Legislature. Statutes of California. State of California. Ch. 29, pp. 281, 283.
  25. ^ Howe & Peters, Engineers' Report to California State Automobile Association Covering the Work of the California Highway Commission for the Period 1911-1920, pp. 11-16
  26. ^ California State Assembly. An act...relating to State highways. Fifty-first Session of the Legislature. Statutes of California. State of California. Ch. 274, pp. 959, 281.
  27. ^ Dennis, T.H. (August 1934). "State Routes Will Be Numbered and Marked with Distinctive Bear Signs". California Highways and Public Works. 11 (8): 20–21, 32. ISSN 0008-1159 – via Archive.org.
  28. ^ Oakland Tribune, classified ads, August 15, 1937: "one acre on Highway 21, south of Walnut Creek"
  29. ^ United States Geological Survey, 1942 San Jose, 1940 Livermore, 1942 Mount Diablo, 1941 Concord, 1940 Carquinez Strait (scale 1:62500)
  30. ^ California State Assembly. An act...relating to state highway routes. 1949 Session of the Legislature. Statutes of California. State of California. Ch. 1467, p. 2555.
  31. ^ California State Assembly. An act to amend Section 374 of, and to add Sections 512 and 543 to, the Streets and Highways Code, relating to state highways. Fifty-seventh Session of the Legislature, 1st Extraordinary Session. Statutes of California. State of California. Ch. 13, p. 3812.
  32. ^ California State Assembly. An act authorizing the acquisition by the Department of Public Works of the ferry system across Carquinez Straits between Benicia and Martinez... 1953 Session of the Legislature. Statutes of California. State of California. Ch. 1737, pp. 3486-3488. [Note that this law accidentally deleted portion (c) of Route 75; an urgency measure passed at the 1954 1st extraordinary session (chapter 8) corrected this error.]
  33. ^ San Mateo Times, State Set to Take Over Benicia Ferry, September 29, 1953
  34. ^ Bureau of Public Roads, General Location of National System of Interstate Highways, 1955: San Francisco
  35. ^ a b "State Highway Routes: Selected Information" (PDF). California Department of Transportation. 1995. pp. 342, 348. Archived from the original (PDF) on February 1, 2015.
  36. ^ H.M. Gousha Company, California, 1963
  37. ^ Oakland Tribune, Lafayette Bypass to Slash Travel Time for Commuters, September 9, 1956: "With another freeway link now under construction northward from Walnut Creek to the Monument..."
  38. ^ United States Geological Survey, Walnut Creek (scale 1:24000), 1959
  39. ^ Oakland Tribune, Ceremony Salutes New Freeway Link, March 23, 1960
  40. ^ a b c California Department of Transportation (July 2007). "Log of Bridges on State Highways". Sacramento: California Department of Transportation.
  41. ^ a b H.M. Gousha Company, San Francisco, 1968
  42. ^ California State Assembly. An act to add Section 253 and Article 3 (commencing with Section 300) to Chapter 2 of Division 1 of, and to repeal Section 253 and Article 3 (commencing with Section 300) of Chapter 2 of Division 1 of, the... 1963 Session of the Legislature. Statutes of California. State of California. Ch. 385, pp. 1173, 1189.
  43. ^ Oakland Tribune, Highway 9 Has a New Number, April 19, 1964
  44. ^ California State Assembly. An act...relating to state highways. 1965 Session of the Legislature. Statutes of California. State of California. Ch. 1371, pp. 3268, 3269.
  45. ^ California State Assembly. An act to amend Sections 253, 307, 317, 322, 334, 342, 347, 349, 361, 363, 372, 373, 374, 379, 384, 390, 407, 408, 443, 455, 470, 486, 514, 517, 548, and 550 of, to add Sections 556, 557, 558, 560... 1965 Session of the Legislature. Statutes of California. State of California. Ch. 1372, p. 3273.
  46. ^ California State Assembly. An act to amend Sections 143.2, 186, 253.1, 253.2, 253.4, 253.5, 253.6, 263.1, 263.5, 263.7, 311, 312, 333, 360, 374, 375, 378, 381, 384, 388, 411, 417, 422, 440, 441, 460, 506, 559, 563, 582, and 620 of, to add... 1975–1976 Session of the Legislature. Statutes of California. State of California. Ch. 1354, pp. 6176, 6178.
  47. ^ a b "Interstate 680 Freeway Interchanges" (PDF). California Numbered Exit Uniform System. California Department of Transportation. September 7, 2018. Retrieved October 21, 2020.

External links

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