Interstate 680 in California

By | October 18, 2022

 

I-680
Get started San Jose
End Cordelia
Length 71 mi
Length 114 km
Route
1 → San Francisco / Salinas

1A-C Downtown San Jose

2 McKee Road

4 Berryessa Road

5 Capitol Avenue

6 Montague Expressway

8 Calaveras Blvd

9 Jacklin Road

10 Scott Creek Road

12 Mission Boulevard

14 Auto Mall Parkway

15 Washington Boulevard

16 Mission Boulevard

18 Vargas Road

20 Andrade Road

21 Calaveras Road

22 Sunol

25 Sunol Boulevard

26 Bernal Avenue

29 Stoneridge Drive

30 → Oakland / Stockton

31 Dublin

34 Bollinger Canyon Road

36 Crow Canyon Road

38 Sycamore Valley Road

39 Diablo Road

40 El Cerro Boulevard

41 El Pintado Road

42 Stone Valley Road

43 Livorna Road

44 Rugear Road

45 Olympic Boulevard

46 → Oakland

47 North Main Street

48 Treat Boulevard

49 Contra Costa Boulevard

50 → Antioch

51 Willow Pass Road

52 Concord Avenue

53 → Hercules / Antioch

54 Pacheco Boulevard

56 Marina Vista

Benicia-Martinez Bridge

58 → Vallejo

60 Industrial Park

61 Lake Herman Road

63 Parish Road

65 Marshview Road

68 Gold Hill Road

70 Green Valley Road

71 → Sacramento

Interstate 680 or I -680 is an Interstate Highway in the U.S. state of California. The highway forms a north-south route along the east side of the San Francisco Bay Area metropolitan area. The highway runs from San Jose to Cordelia and is 114 kilometers long. I-680 is known in part as the Sinclair Freeway.

  • ElectronicsMatter: State facts of California, covering history, geography, demography, economics, politics, and administrative division of California.

Travel directions

I-680 at Alamo, between Dublin and Walnut Creek.

Congestion on the ‘Sunol Grade’ north of San Jose.

The freeway begins at an interchange with US 101 and Interstate 280 in San Jose, the largest city in the metropolitan area with 1 million inhabitants. There are 2×4 lanes available and the highway turns north. One passes through the eastern neighborhoods of San Jose, and many connections are shaped like a cloverleaf. You then pass through the suburb of Milpitas. Here, I-680 parallels Interstate 880. The next major city is Fremont, the 4th city of the conurbation. In Fremont, I-680 suddenly turns with a wide bend to the east, the wide median strip indicates that a highway should once have gone straight here.

One then enters the mountains, which encircle the San Francisco Bay on all sides. The highway leads here over the infamous ‘Sunol Grade’. After about 16 kilometers you enter the row of eastern suburbs, of which Pleasanton is the first. This is one of the richest cities in the United States. I-680 will then have 2×3 lanes. At Dublin, one crosses Interstate 580, which runs east from Oakland. This is the first opportunity to head east after San Jose. One passes through the suburbs of San Ramon and Danville. These are the more expensive suburbs of the conurbation. In Walnut Creek one crosses State Route 24, which leads to Oakland. The section through Walnut Creek is a lot busier due to traffic from SR-24 and also has 2×5 lanes. At Pleasant Hill, State Route 242 exits, which also provides heavy traffic to the eastern suburbs of Concord, Pittsburg, and Antioch. Larger industrial estates are located in Concord between I-680 and SR-242.

At Pacheco, one crosses State Route 4, which runs from Hercules to Antioch. Then you arrive in the suburb of Martinez. Here one crosses the Carquinez Strait, a strait between San Pablo Bay and Suisun Bay. This goes through the Benicia-Martinez Bridge. Immediately after, in Benicia, Interstate 780 exits, which leads to Vallejo. Parallel to I-680 is Suisun Bay, where about 80 old naval ships are rusting in the water. On the other side of the highway is an oil refinery. I-680 ends a little further in Cordelia on Interstate 80 to Sacramento.

  • Fun-wiki: Brief information of the state California, covering basic history and geography as well as top cities of California.

History

The highway was first planned in 1955, when a ring road around the San Francisco area was proposed. This was at the same time as I-280 to San Francisco. In the late 1950s, the first section between Walnut Creek and Pleasant Hill was opened. On March 22, 1960, a short section connecting State Route 24 opened the highway to Oakland. During the 1960s, the highway was then extended north and south. In 1962, the Benicia-Martinez Bridge opened over the Carquinez Strait, eliminating the last car ferry service in the region. The last section of the highway was opened at San Jose in the early 1970s.

Widenings

Between 1986 and 1989, part of I-680 in Dublin was widened. In 1990, the highway between Fremont and Pleasanton was widened. In 1994 the section between Dublin and Walnut Creek followed. Between 1995 and 1998, the route between Walnut Creek and Concord was widened.

Benicia-Martinez Bridge

One of the biggest modifications was the construction of a second Benicia-Martinez Bridge, which opened on August 25, 2007. The original 1962 bridge cost $25 million, the new 2007 bridge cost a whopping $1.3 billion, while the original estimates were $300 million. Like many projects in the region, this bridge also got out of hand in terms of delays and costs.

HOV lane

I-680 has the Bay Area’s longest HOV lane, a 40-mile car pool lane between Martinez and San Ramon. The last part of this opened on August 24, 2020.

express lanes

On September 20, 2010, a 23-kilometer HOT lane in the San Jose area opened to traffic, but only heading south. Between 2018 and 2020, the first phase of the express lane to the north was constructed, from Auto Mall Parkway to CA-84, over the notoriously congestion-prone Sunol Grade. Between October 2018 and September 2021, a 19-kilometer express lane was built south between Martinez and Walnut Creek.

Sunol Grade

I-680 over the Sunol Grade between Pleasanton and Fremont has been one of the most congested highways in the United States, due to Silicon Valley’s many jobs, but exorbitant housing prices there keep commuters living in the interior of Alameda County.. Towards the south, an HOV lane has now been converted into a HOT lane, but towards the north, only 3 lanes were available. Work began in early 2018 to build the first phase of an express lane northbound between the Auto Mall Parkway and CA-84. The extra lane opened on October 29, 2020, first as a carpool lane, but in 2021 as an express lane with toll.

Opening history

From Unpleasant Length Date
46B 50 6 km 00-00-1960
45A Main Street 46B 2 km 00-00-1960
65 Goodyear Road 70 8 km 00-00-1961
50 58 13 km 00-00-1962
16 Mission Boulevard 21 Vallecitos Road 8 km 00-00-1963
38 Sycamore Valley Road 45A Main Street 11 km 00-00-1964
30 31 Alacosta Boulevard 2 km 00-00-1965
31 Alacosta Boulevard 38 Sycamore Valley Road 11 km 00-00-1966
58 65 Goodyear Road 11 km 00-00-1966
21 Vallecitos Road 30 14 km 00-00-1967
8 16 Mission Boulevard 13 km 00-00-1971
0 8 13 km 00-00-1974

Traffic intensities

Exit Location 2008 2012 2016
Exit 1 San Jose ( I-280 ) 159,000 148,000 165,000
Exit 2 San Jose (King Road) 225,000
exit 8 San Jose ( SR-237 ) 144,000 130,000 146,000
Exit 30 Pleasantton ( I-580 ) 148,000 167,000 179,000
exit 46 Walnut Creek ( SR-24 ) 246,000 256,000 261,000
Exit 50 Concord ( SR-242 ) 238,000 230,000 267,000
exit 53 Martinez ( SR-4 ) 132,000 112,000 143,000
exit 58 Benicia ( I-780 ) 100,000 98,000 85,000
Exit 71 Cordelia ( I-80 ) 60,000 57,000 83,000

Interstate 680 in California