Interstate 238

Interstate 238
Route information
Defined by S&HC § 538
Maintained by Caltrans
Length:	2.126 mi[1] (3.421 km)
Existed:	May 1983 by FHWA[2] – present
Major junctions
South end:	I-580 / SR 238 in Castro Valley
North end:	I-880 in San Leandro
Highway system
Interstate Highway System Main Auxiliary Suffixed Business State highways in California List Pre-1964 History Unconstructed Deleted Freeway Scenic ← SR 237 SR 238 →

Interstate 238 (I-238) is a short auxiliary route of the Interstate Highway System in the San Francisco Bay Area in the U.S. state of California. Part of State Route 238 (SR 238) until 1983, and still considered part of SR 238 by the California Department of Transportation (Caltrans), it connects I-580 in Castro Valley (where SR 238 continues south) with I-880 in San Leandro. Despite running in an east–west direction, it is signed north–south, as the rest of SR 238 is more north–south than east–west.

The number does not follow established rules for numbering Interstates, as there is no I-38. As it connects two auxiliary routes of I-80, it would normally use a three-digit number ending in 80, but of the nine possible numbers, two (180 and 480) were in use by State Routes (the latter an Interstate until 1968), and the remainder were already in use by other California auxiliary routes. (I-880 was designated at the same time as I-238.)

This route is part of the California Freeway and Expressway System.^[3]

Route description

Although the 2.16-mile-long (3.48 km) I-238 goes in an east–west direction from Castro Valley to San Leandro, Caltrans officially signs it as a north–south freeway since the rest of SR 238 is more north–south. The south (or east) terminus of I-238 is at its interchange with InterstateI-580 and SR 238 in Castro Valley. From there, it enters into the southern portion of the census-designated place of Ashland, running parallel to its border with Cherryland. Then after entering San Leandro, I-238 terminates at I-880.

I-238 and I-880 are used as an alternate truck route between Castro Valley and Oakland; trucks over 4.5 short tons (4.1 t) are prohibited through the latter on I-580.^[4]

History

The section of road that is now I-238 had no signed number before the 1964 renumbering; it was pre-1964 Legislative Route 228 (along with an unbuilt extension west to unbuilt SR 61, which is still included in the SR 238 definition).

The segment from what is now I-580 to I-880 was built as a freeway in 1956.^[5] The rest of SR 238 south to I-680 in Fremont was also planned to be upgraded to a freeway (parallel to present I-880), but after it was unsuccessfully submitted to the Interstate Highway System in October 1968,^[2] and after several lawsuits, it never got off the ground.^[6]

When present I-880 was added to the Interstate Highway System as a renumbering of part of SR 17, the short piece of SR 238 connecting I-880 to I-580 was also added; both were non-chargeable routes (not eligible for Interstate Completion funds). Both numbers—I-238 and I-880—were approved by the American Association of State Highway and Transportation Officials (AASHTO) on July 7, 1983.^[2] The interchanges with I-580 and I-880 were rebuilt from 1988 to 1994, in part to add missing ramps between I-238 and I-880 towards the south.^[5] Prior to the completion of the ramps, access was provided by Hesperian Boulevard.

As AASHTO said on July 7, 1983, when approving the designation,

Caltrans responded on July 27, 1983:

With the deletion of SR 480 in 1991, the "480" designation is once again available. However, there has been no push since then to renumber I-238 to I-480.

In September 2006, a project began to reconstruct the entire length of I-238, including a reconfigured interchange with I-880 and an added travel lane in each direction. Additionally, almost all of the bridges and overpasses were replaced with new ones meeting current earthquake resistance standards. The project was completed in October 2009, six months ahead of schedule.^[8]

Exit list

Except where prefixed with a letter, postmiles were measured on the road as it was in 1964, and do not necessarily reflect current mileage. R reflects a realignment in the route since then.^[1] The entire route is in Alameda County.

Location	Postmile [1][5][9]	Exit [10][11]	Destinations	Notes
Castro Valley	R14.47	14	I-580 (MacArthur Freeway) – Oakland, Stockton SR 238 / Castro Valley Boulevard – Hayward	Southbound exit and northbound entrance; roadway continues as SR 238
Ashland	14.95	15	SR 185 (Mission Boulevard, East 14th Street)
San Leandro	16.28	16B	Hesperian Boulevard – San Lorenzo	Northbound exit and southbound entrance
	16.70	16A	I-880 south (Nimitz Freeway) – San Jose, San Mateo Bridge	Northbound exit and southbound entrance
	16.70	17A	Washington Avenue	Northbound exit and southbound entrance
	16.70	17B	I-880 north (Nimitz Freeway) – Oakland	Northbound exit and southbound entrance
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Incomplete access

References

External links

• Indigestion 238: A history of the route and a full explanation of its numbering
• I-238 California: Kurumi

v t e Main Interstate Highways Signed 2 4 5 8 10 12 15 16 17 19 20 22 24 25 26 27 29 30 35 37 39 40 43 44 45 49 55 57 59 64 65 66 68 69 70 71 72 73 74 75 76 (W) 76 (E) 77 78 79 80 81 82 83 84 (W) 84 (E) 85 86 (W) 86 (E) 87 88 (W) 88 (E) 89 90 91 93 94 95 96 97 99 H-1 H-2 H-3 Unsigned A-1 A-2 A-3 A-4 PRI-1 PRI-2 PRI-3 Lists Primary Main Intrastate Suffixed Temporary Future Gaps Auxiliary Main Future Unsigned Other Standards Business Bypassed Tolled Major Interstates highlighted