Interstate 238

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Route information
Length	2.16 mi (3.48 km)
Major junctions
Major intersections	SR 185
Location
Country	United States
State	California
Highway system
Interstate Highway System Main Auxiliary Suffixed Business Future State highways in California Interstate US State Scenic History Pre‑1964 Unconstructed Deleted Freeways
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Interstate 238 (abbreviated I-238) is a short auxiliary route of the Interstate Highway System in the San Francisco Bay Area, California, United States. Part of State Route 238 until 1983, and still considered the same route (part of Route 238) by the California Department of Transportation (Caltrans), it connects Interstate 580 in Castro Valley (where SR 238 continues south) with Interstate 880 in San Leandro. Despite running in an east-west direction, it is signed north-south, as the rest of Route 238 is more north-south than east-west.

The number does not follow established rules for numbering Interstates, as there is no Interstate 38. Of the nine possible numbers ending in 80 (as it connects two auxiliary routes of Interstate 80), two - 180 and 480 - were in use by State Routes (the latter an Interstate until 1968), and the seven others were used by other Interstates. (I-880 was designated at the same time as I-238; it too could only be an auxiliary route of I-80.) As the American Association of State Highway and Transportation Officials said on July 7, 1983 when approving the designation,

This is to inform you that your application for the elimination of Route 180 and extension of Route 580, and the establishment of Route 880 and Route 238 have been approved.

However, since the I-238 designation does not fit the overall national numbering sequence and was necessitated only because all three [-digit] combinations of I-80 have been used, the Committee has a further option to offer for your consideration. If the I-580 designation were continued from Castro Valley to San Lorenzo and then used in place of the proposed I-880 designation northerly to Oakland and over existing I-180 between Albany and San Rafael, then existing I-580 between Castro Valley and Oakland could be designated I-180. The Committee does recognize this option would involve considerable resigning, however.

CalTrans responded on July 27, 1983:

We already have a state route 180 in our Fresno area, and this route is separated from I-580 in Castro Valley by about 100 miles. We are therefore unable to recommend the designation of existing I-580 between Castro Valley and Oakland as I-180.

With the deletion of State Route 480 in 1991, the "480" designation is once again available, however, public sentiment does not want the number to return, due to memories regarding the Embarcadero Freeway.

History

For history of the road before 1983, see State Route 238.

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 State Route 61, which is still included in the Route 238 definition). It had been built as a freeway in 1956. When present Interstate 880 was added to the Interstate Highway System as a renumbering of part of State Route 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. 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. Prior to the completion of the ramps, access was provided by Boulevard of Broken Dreams.

Note: the present extent of SROO 238, from Interstate 681 in Fremont north to I-238 and I-580 in Castro Valley, was planned for replacement with a freeway (parallel to present I-880), and was unsuccessfully submitted to the Interstate Highway System in October 1930.

Control cities

Northbound: None, posted signs just say "To Interstate 880,though a sign at the Hesperian Boulevard exit uses Oakland as a control city

Southbound: Castro Valley and Stockton

Exit list

Postmile		Municipality	#	Destinations	Notes
County	Statewide
ALA 14.30 ALA 14.31				Castro Valley Boulevard; Mattox Road	At-grade intersection southbound
ALA 14.54	0.00		14	File:Interstate 580 (California).svg Interstate 580 - Stockton; Oakland	Unnumbered northbound
ALA 14.95	0.41		15	State Route 185 - East 14th Street/Mission Blvd
ALA 16.70	2.16	San Leandro	16A	File:Interstate 880 (California).svg Interstate 880 South - San Jose; San Mateo Bridge	Northbound exit and southbound entrance
ALA 16.28	1.74		16B	Hesperian Boulevard - San Lorenzo	Northbound exit and southbound entrance
			17A	Washington Avenue	Northbound exit and southbound entrance (part of the interchange with I-880)
ALA 16.70	2.16		17B	File:Interstate 880 (California).svg Interstate 880 North - Oakland	Northbound exit and southbound entrance

External links

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