California State Route 237

State Route 237
Southbay Freeway
Route information
Maintained by Caltrans
Length	11 mi (18 km)
Major junctions
West end	SR 82 in Mountain View
Major intersections	SR 85 in Mountain View US 101 in Sunnyvale I-880 in Milpitas
East end	I-680 in Milpitas
Location
Country	United States
State	California
Highway system
State highways in California Interstate US State Scenic History Pre‑1964 Unconstructed Deleted Freeways
← SR 236 → I-238

State Route 237 runs from El Camino Real (SR 82) in Mountain View to Interstate 680 in Milpitas. It runs south of the San Francisco Bay, connecting the East Bay to the Peninsula.

This route is part of the California Freeway and Expressway System.

Route description

It intersects with Highway 101 at the southern corner of Moffett Field. It also has a major intersection with Interstate 880. Westbound traffic can connect to Highway 85 southbound, but the eastbound traffic connection to 85 northbound is labeled as an exit for U.S. 101.

Half a mile from the highway's western terminus, to the I-880 intersection, Route 237 is constructed to Interstate standards, and is named the Southbay Freeway. It is not part of the Interstate system, however, despite a sign on the ramp to it from Northbound I-680 to the contrary. East of I-880 in Milpitas, it becomes a surface street, Calaveras Boulevard, and the highway designation terminates at the intersection with I-680. West of El Camino Real in Mountain View, it becomes a surface street, Grant Road.

It begins at a junction with El Camino Real (CA-82) in Mountain View as a freeway with two lanes in each direction, although most traffic comes from State Route 85. After an intersection with US Route 101, Mathilda Avenue, and Fair Oaks Avenue, a carpool lane is added for a total of 3 lanes in either direction. It remains like this as it passes the companies where commuters work, to its east end of the freeway at I-880, where most eastbound traffic is directed to northbound 880. The route becomes a street, Calaveras Boulevard, in Milpitas, terminating at I-680. Calaveras Blvd becomes Calaveras Road.

Route 237 is known for the many Silicon Valley companies that line its route.

Before Route 237 was upgraded to freeway status in the mid-1990s, it was a 4-6 lane street, known as Alviso-Milpitas Road or Milpitas-Alviso Road depending on different maps showing the description.

The Route 237 corridor has long been sought as a location for a freeway connector between Interstates 680 and 880. Many possible sites have been suggested, from Montague Expressway in North San Jose to Mission Boulevard in Fremont. One map printed before 237's construction to freeway standards between Alviso and 880 showed a new freeway across bay wetlands between Alviso and the Scott Creek Road interchange in South Fremont. Grading and underpasses for a freeway interchange are presently visible along 680 near Scott Creek Road. [1]

Route 237 is known for a number of companies that define Silicon Valley's technological landscape. Many major software and hardware manufacturers have their headquarters along 237. Some of these manufacturers include Lockheed-Martin, Brocade Communications Systems, Nortel Networks, Cisco Systems, Yahoo!, TiVo and Ariba.

Route 237 also passes Moffett Federal Airfield, a large former military air base in the Bay Area, and Onizuka Air Force Station, locally known as the blue cube.

Highway 237 Bikeway

The Highway 237 Bikeway is a 5-mile (8.0 km) pedestrian and bicycle path that parallels State Route 237. The majority of the path is separated from vehicular traffic, however, two sections comprising a total of 1.5 miles (2.4 km) follow an on-street alignment adjacent the freeway.

This bikeway serves as an important connector in the network of trails in San Jose and Santa Clara County. It intersects with the Guadalupe River Trail, which provides access to Downtown San Jose, as well as the San Tomas Aquino Creek and Coyote Creek trails.

Major intersections

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 entire route is in Santa Clara County.

Location	Postmile	Exit	Destinations	Notes
Mountain View	R0.00		Grant Road	Continuation beyond SR 82
	R0.00	1A	SR 82 (El Camino Real) – Mountain View, Los Altos
	West end of freeway
	R0.38	1A	US 101 north (via SR 85 north) – San Francisco	Eastbound exit and westbound entrance
	R0.38	1B	SR 85 south to SR 82 south – Los Gatos, Santa Cruz	Westbound exit and eastbound entrance
	R0.61	1B	Dana Street, Evelyn Avenue, Whisman Road	Signed as exit 1C westbound
	M1.55	2	Middlefield Road, Maude Avenue
Sunnyvale	2.48	3A	US 101 south (Bayshore Freeway) – San Jose	Westbound exit is via exit 3B
	2.48	3A	US 101 north (Bayshore Freeway) – San Francisco	Eastbound exit is via exit 3B
	2.99	3B	Mathilda Avenue – Sunnyvale	Former SR 9 south
	R3.97	4	Fair Oaks Avenue	Eastbound exit and westbound entrance
	R4.60	5	Lawrence Expressway (CR G2), Caribbean Drive
Santa Clara	R5.83	6	Great America Parkway, Lafayette Street
San Jose	6.87	7	North First Street
	8.02	8	Zanker Road
Milpitas	R9.13	9A	McCarthy Boulevard
	9.34	9	I-880 (Nimitz Freeway) – Oakland, San Jose	Signed as exits 9B (south) and 9C (north)
	East end of freeway
			Serra Way to Main Street
			Abel Street to Main Street
	10.00	10	Main Street	Interchange; westbound exit and eastbound entrance; former SR 238
			Milpitas Boulevard
	11.08	11	I-680 – Sacramento, San Jose	Interchange; signed as exits 11A (south) and 11B (north)
	11.08		Calaveras Boulevard	Continuation beyond I-680
1.000 mi = 1.609 km; 1.000 km = 0.621 mi

See also

• List of California State Routes

External links

• Caltrans: Route 237 highway conditions
• California Highways: SR 237
• Highway 237 / I-880 Interchange Reconstruction Project