California State Route 238

State Route 238
Mission Boulevard, Foothill Boulevard
Route information
Defined by S&HC § 538
Maintained by Caltrans
Length:	14.393 mi[2] (23.163 km)
Existed:	July 1, 1964[1] – present
Major junctions
South end:	I-680 in Fremont
	SR 92 / SR 185 in Hayward
North end:	I-238 / I-580 in Castro Valley
Highway system
State highways in California(list • pre-1964) History • Unconstructed • Deleted • Freeway • Scenic ← I-238 SR 241 →

State Route 238 (SR 238) is a north–south highway in the U.S. state of California. The route is a divided multilane surface highway in the southeastern part of the San Francisco Bay Area. SR 238 connects Interstate 580 in Castro Valley and Interstate 680 in Fremont.

Route description

SR 238 goes through Hayward and Union City parallel to the Hayward hills. It formerly contained a segment of east–west freeway now designated as Interstate 238 and, until Interstate 680 was completed in the area and supplanted it completely as a through route, extended to San José, California at its intersection with U.S. Route 101. Locally it is designated Mission Boulevard from I-680 to the intersection with State Route 92 and State Route 185 (which continues as Mission Boulevard), then from that intersection to I-580 as Foothill Boulevard.

Mission Boulevard

Mission Boulevard is the road that passes in front of Mission San José, the historic Spanish Mission founded in 1797, for which the road is named. Mission Boulevard proceeds in both directions from the Mission, but mainly northwest through Fremont, Union City, and Hayward. At the north end of Hayward it changes its name to East 14th Street, which continues as a major thoroughfare going through San Leandro and Oakland. Since it runs along the base of the hills, Mission Boulevard nearly coincides with the Hayward Fault, a major earthquake fault, for almost the entire length of the Boulevard.

Mission Boulevard joins the historic centers of the Mission San Jose and Niles districts of Fremont (formerly independent towns), the Decoto district of Union City (formerly an independent town), and Hayward.

History

See also: Interstate 238

Before California massively renumbered its state highways in 1964, SR 238 was part of State Route 9. The segment of what is now Interstate 238 was built as a freeway in 1956,^[3] before it became part of the Interstate Highway System in 1983.^[4]

For several decades, SR 238 from Hayward to Fremont was also planned to be upgraded to a freeway, called the "Mission" or "Foothill" freeway.^[1] It was submitted to the Interstate Highway System in October 1968 but was rejected.^[4] Then after a series of lawsuits and appeals, Caltrans had to abandon the project in 2004 and sell off the property it had acquired in the name of eminent domain along the proposed route.^[1]

As an alternative, SR 238 is proposed to be expanded from two lanes in each direction to three lanes in each direction along the majority of its width. Changes proposed also include a one way circulation through Downtown Hayward, and various improvements to traffic signals and closure of minor streets intersecting with SR 238.^[5] Construction on the Route 238 Corridor Improvement Project began in July 2010.

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 Alameda County.

Location	Postmile [2][6][7]	Destinations	Notes
Fremont	0.00	Mission Boulevard	Continuation beyond I-680
	0.00	I-680 – San Jose, Sacramento	Interchange
		Stevenson Boulevard
		Walnut Avenue, Morrison Canyon Road
	3.31	SR 84 west (Mowry Avenue) – Centerville District, Newark, Dumbarton Bridge	South end of SR 84 overlap
	3.64	SR 84 east (Niles Canyon Road) / Niles Boulevard – Sunol, Livermore, Niles District	North end of SR 84 overlap
Union City	6.78	Decoto Road – Decoto District, Dumbarton Bridge
		Whipple Road – Alvarado District
Hayward	9.32	Alquire Parkway, Industrial Parkway to I-880
	9.94	Tennyson Road
	11.20	Harder Road – San Mateo Bridge
	12.61	SR 92 (Jackson Street) – San Mateo Bridge, San Mateo, San Jose
	12.61	SR 185 (Mission Boulevard)
	13.12	A Street
Castro Valley	14.29	Castro Valley Boulevard, Mattox Road	Interchange northbound and at-grade intersection southbound
	R14.47	I-580 (MacArthur Freeway) – Oakland, Stockton	Interchange; northbound exit and southbound entrance
	R14.47	I-238 to I-880	Interchange; northbound exit and southbound entrance
1.000 mi = 1.609 km; 1.000 km = 0.621 mi      Concurrency terminus •      Closed/Former •      Incomplete access •      Unopened

References

1. ^ ^{a b c} California Highways: Interstate 238
2. ^ ^{a b} California Department of Transportation, State Truck Route List (XLS file), accessed February 2008
3. ^ January 1, 2006 California Log of Bridges on State Highways
4. ^ ^{a b} California Highways: Interstate Highway Types and the History of California's Interstates
5. ^ Route 238 Corridor Improvement Project
6. ^ California Department of Transportation, Log of Bridges on State Highways, July 2007
7. ^ California Department of Transportation, All Traffic Volumes on CSHS, 2005 and 2006