Interstate 680 (I-680) is a north-south
Interstate Highway in
Northern California.
It curves around the
eastern cities of the San Francisco Bay Area
from San Jose
to Interstate
80 at Cordelia
, 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
.
I-680 is
part of the State Scenic Highway
System from SR 238 in
Fremont
north to SR
24 in Walnut Creek
, and is eligible for said system from SR 238 south
to the Alameda
-Santa Clara County
line.
Route description
The portion of this route from the Route 280/US101 junction to the
Santa Clara/Alameda County line is named the
Joseph
P. Sinclair Freeway, after the District
Engineer for District 4 Division of Highways (now Caltrans) from
1952 to 1964 pursuant to Assembly Concurrent Resolution 104,
chapter 168 in 1967.
The portion of this route between Alcosta Boulevard and the
intersection with I-580 is officially named the "Officer John Paul
Monego Memorial Freeway." It was named after Dublin Police Officer
John Paul Monego, who died on December 12, 1998, in the line of
duty at the age of 33 years, while responding to a takeover
robbery. Named by Senate Concurrent Resolution 60, enrolled August
18, 2000.
The portion of this route from Route 24 to Route 4 is historically
part of "El Camino Sierra" (The Road to the Mountains).
The portion of this route from about the Livorna Road interchange
in Walnut Creek/Alamo to the Alcosta Blvd. interchange in San Ramon
appears to be named the "Donald D. Doyle Highway". While serving in
the California Assembly from 1953 to 1958, Donald D. Doyle
co-authored the Short-Doyle Mental Health Act and authored
legislation creating the ferry boat transportation system between
Benecia and Martinez. The signs indicating this were erected in
1998.
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.
I-680 begins at a junction with
I-280 and
US 101 (
Bayshore Freeway), and heads northeast and
north-northwest through the northeast part of that city.
After
passing 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 a hilly area. 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 Cordelia
, lies between a hilly area to the west and a
marshy area (along the Suisun Bay and Cordelia Slough
) to the east.
History
.jpg/180px-View_from_I-680_(2).jpg)
Descending from Mission Pass
northbound
By the
1920s, a road ran south from Martinez
through Walnut Creek
, Dublin
, Danville
, and Sunol
to Mission San Jose
, where it met State Highway 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
. 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
.
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 Cordelia
towards Sacramento
and Oregon
.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 The portion north
from Benicia to Cordelia became part of Route 74 in 1935,
when Route 7 was realigned to the more direct American
Canyon
route that is now I-80. None of the
aforementioned roads were given state sign route numbers in 1934,
when that system was laid out, but by 1937 they had been numbered
Sign Route 21. 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, follewed
Route 5 along
Mission Boulevard
to Mission San Jose (this part later became an
overlap 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, and Pacheco Boulevard.
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.
The ferry approach in Benicia became a spur of Route 74 in 1947,
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. Ownership was
transferred just after midnight on
October
6,
1953.

I-680 and other Bay Area Interstates
as planned in 1955
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
. The first piece of I-680 freeway built,
other than the pre-existing 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
. A southerly extension, bypassing downtown
Walnut Creek to South Main Street, opened on March 22, 1960, connecting with
the SR 24 freeway to Oakland
. 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 Cordelia,
which became the only remaining piece of SR 21, was also upgraded
to freeway standards.H.M. Gousha
Company, San Francisco, 1968
In the
1964
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, : "Route 17 is from: (a) Route 1 near Santa
Cruz to Route 101 near Story Road. (b) Route 101 near San Jose to
Route 680 near Warm Springs. (c) Route 680 near Warm Springs to
Route 580 in Oakland..." "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." 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. This was very
short-lived, as the
Bureau of
Public Roads approved a shift in the south end of I-680 in
October 1964. The legislature changed the routes in 1965, swapping
Routes 17 and 680 south of Warm Springs, and creating a new
SR 262 on the short
roadway at Warm Springs where they had
overlap to switch sides. However, until I-680
was completed in the early-to-mid 1970s, it remained signed along
the Nimitz Freeway, and the old road between San Jose and Warm
Springs continued to be marked as SR 238. One more change was made
to the routing of I-680: in July 1973, the remainder of SR 21, from
Benicia to Cordelia, 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.
Future
There is
a proposal to add a high-occupancy
toll (HOT) lane along I-680 between Alameda
and Santa Clara
counties. Under the plan, the existing
southbound carpool lane along the 14-mile stretch between SR 84 and
SR 237 would be modified to be the HOT lane. Solo drivers would
then be required to use a
FasTrak
transponder. There are currently no plans to add northbound HOT
lanes on I-680, however.
Exit list
- Note: Except where prefixed with a letter, postmiles were measured in 1964, based on the
alignment as it existed at that time, and do not necessarily
reflect current mileage. The numbers reset at county lines; the
start and end postmiles in each county are given in the county
column.
County |
Location |
Postmile
|
# |
Destinations |
Notes |
Santa Clara
SCL M0.00-M9.94
|
San Jose |
M0.00 |
1A |
|
Continuation beyond US 101 |
M0.00 |
1B |
|
Southbound exit and northbound entrance |
M0.39 |
1A |
King Road |
Signed as exit 1C southbound |
M1.19 |
1B |
Jackson Avenue |
Northbound exit and southbound entrance |
M1.41 |
1C |
Capitol Expressway (CR G21) |
Signed as exit 1D southbound |
M1.74 |
2A |
Alum Rock Avenue (SR
130) |
|
M2.38 |
2B |
McKee Road |
|
M3.84 |
4 |
Berryessa Road |
|
M4.80 |
5A |
Hostetter Road |
Southbound exit is via exit 5 |
M5.07 |
5B |
Capitol Avenue |
Signed as exit 5 southbound |
M6.17 |
6 |
Montague
Expressway (CR G4),
Landess Avenue |
|
Milpitas |
M7.65 |
8 |
|
|
M8.50 |
9 |
Jacklin Road |
|
Alameda
ALA M0.00-R21.88
|
Fremont |
M0.13 |
10 |
Scott Creek Road – Warm Springs District |
|
M2.38 |
12 |
|
Former SR 21 north |
M4.02 |
14 |
Auto Mall Parkway, Durham Road |
|
M5.37 |
15 |
Washington Boulevard – Irvington District |
|
R6.40 |
16 |
|
Former SR 21 south |
R7.48 |
18A |
Vargas Road |
Signed as exit 18 southbound |
|
R8.31 |
18B |
Sheridan Road |
Southbound exit is via exit 20 |
|
R9.71 |
20 |
Andrade Road |
|
|
R11.04 |
21A |
|
South end of SR 84 overlap; signed as exit 21 northbound;
former SR 21 north |
|
R11.85 |
21B |
|
North end of SR 84 overlap; southbound exit is via a U-turn at
exit 21 |
|
R12.44 |
22 |
Sunol |
Southbound exit and northbound entrance; former SR 21 |
Pleasanton |
R15.26 |
25 |
Sunol
Boulevard, Castlewood Drive – Pleasanton |
|
R16.75 |
26 |
Bernal Avenue – Pleasanton |
|
R19.30 |
29 |
Stoneridge Drive |
|
R20.06 |
30 |
|
Signed as exits 30A (east) and 30B (west) |
Dublin |
R20.39 |
30A |
Dublin Boulevard |
No northbound exit; former US 50 |
Contra Costa
CC R0.00-25.46
|
San Ramon |
R0.01 |
31 |
Alcosta Boulevard – Dublin |
|
R2.89 |
34 |
Bollinger Canyon Road |
|
R4.18 |
36 |
Crow Canyon Road – San
Ramon |
|
Danville |
R6.76 |
38 |
Sycamore Valley Road |
|
R7.55 |
39 |
Diablo Road – Danville |
|
R8.18 |
40 |
El Cerro Boulevard |
|
R8.75 |
41 |
El Pintado Road |
Northbound exit is via exit 40 |
Alamo |
R10.37 |
42 |
Stone Valley Road |
Signed as exits 42A (east) and 42B (west) |
R11.28 |
43 |
Livorna Road |
|
Walnut Creek |
R12.61 |
44 |
Rudgear Road |
Southbound exit is via exit 45A |
13.08 |
45A |
South
Main Street – Walnut Creek |
No northbound entrance; former SR 21 |
13.93 |
45B |
Olympic Boulevard |
|
14.38 |
46A |
|
Signed as exit 46 southbound |
14.85 |
46B |
Ygnacio Valley Road |
Northbound exit and southbound entrance |
15.61 |
47 |
North
Main Street – Walnut Creek |
Former SR 21 |
16.40 |
48 |
Treat Boulevard, Geary Road |
|
Pleasant Hill |
R17.29 |
49A |
Contra Costa Boulevard – Pleasant
Hill |
Northbound exit and southbound entrance; former SR 21 |
R17.70 |
49B |
Monument Boulevard, Gregory Lane |
Signed as exit 49 southbound; former SR 24 east |
Concord ,
Pleasant
Hill
|
R18.71 |
50 |
|
Northbound exit and southbound entrance |
19.04 |
51 |
Willow Pass Road, Taylor Boulevard |
|
19.86 |
52 |
Concord Avenue, Burnett Avenue –
Pacheco , Concord |
|
|
21.19 |
53 |
|
|
|
22.43 |
54 |
Pacheco Boulevard |
Former SR 21 |
Martinez |
24.26 |
56 |
Marina Vista, Waterfront Boulevard –
Martinez |
|
Benicia-Martinez Bridge over Carquinez Strait |
Solano
SOL L0.00-R13.13
|
Benicia |
0.68 |
58A |
|
Signed as exit 58 southbound |
R1.00 |
58B |
Bayshore Road |
Northbound exit and southbound entrance |
R1.46 |
60 |
Industrial Park |
Southbound exit and northbound entrance |
R2.82 |
61 |
Lake Herman Road |
Former SR 21 south |
|
R5.02 |
63 |
Parish Road |
|
|
R7.32 |
65 |
Marshview Road |
|
Fairfield |
R10.02 |
68 |
Gold Hill Road |
|
12.63 |
70 |
Green
Valley Road – Cordelia |
Northbound exit and southbound entrance |
13.13 |
71 |
|
Northbound exit and southbound entrance; signed as exits 71A
(east) and 71B (west) |
References
External links