Interstate 5, or I-5, is an interstate highway along the west coast of the United States. Its odd (as opposed to even) number indicates that it is a north-south highway (though in much of the southern half of California it runs in a northwest-southeast direction). Its south terminus is at the international border between the United States and Mexico a few miles south of San Diego. Its north terminus is at the international border between the United States and Canada near Blaine, Washington.

This highway links the majority of the metropolitan areas in California (San Diego, Los Angeles, and Sacramento); Oregon (Eugene, Salem, and Portland); and Washington (Olympia, Tacoma, and Seattle).

A metropolitan area which is not linked by this highway is San Francisco. San Francisco is about 80 miles (130 km) west of the I-5 alignment. Nevertheless, San Francisco is still 'interstate accessible' via Interstate 80 (I-80), a major east-west interstate that junctions with I-5 in Sacramento.

This interstate highway, Interstate 15, Interstate 10, Interstate 8, and U.S. Route 101 serve as the primary roads that link the Los Angeles/San Diego Metropolitan areas and the rest of the nation.

Detailed information on the sections of I-5 in Southern California can be found on the Golden State Freeway, Santa Ana Freeway, and San Diego Freeway pages.

Interstate 5 southbound approaching Weed, California and Mt. Shasta

History

The portion of this highway from Los Angeles, California to San Ysidro, California was also co-signed as US 101 until the late 1960s.

The portion of this highway from Lebec, California to Red Bluff, California roughly follows old US 99W.

The western branch of Interstate 5, called Interstate 5W, was replaced by I-505 and I-580, the main spur into the San Francisco Bay Area. What is now I-5 would have been designated Interstate 5E.

Length

Major cities along the route

• San Ysidro, California (border of Mexico)
• San Diego, California
• Santa Ana, California
• Anaheim, California, location of Disneyland
• Los Angeles, California
• Burbank, California
• Santa Clarita, California
• Stockton, California
• Sacramento, California
• Redding, California
• Ashland, Oregon
• Medford, Oregon
• Eugene, Oregon
• Salem, Oregon
• Portland, Oregon
• Vancouver, Washington
• Olympia, Washington
• Tacoma, Washington
• Seattle, Washington
• Everett, Washington
• Bellingham, Washington
• Blaine, Washington (border with Canada, becoming British Columbia provincial highway 99 northbound)

In California south of Tracy, I-5 skirts along the more remote western edge of the great Central Valley, and thus here is removed from population centers such as Bakersfield, California and Fresno, California with state highways providing connections. Interstate 580 provides a loop-route connection to San Francisco, California and the San Francisco Bay Area.

Junctions with other interstates in California (south to north)

• Interstate 805 (bypass) in south San Diego, California
• Interstate 8 in San Diego, California
• Interstate 805 (bypass)in north San Diego, California
• Interstate 405 (bypass) at the El Toro Y in El Toro, California
• Interstate 605 in Santa Fe Springs, California
• Interstate 710 southeast of downtown Los Angeles, California
• Interstate 10 at the East Los Angeles Interchange complex, east of downtown Los Angeles, California
• Interstate 405 (bypass) in Sylmar, California
• Interstate 210 in Sylmar, California
• Interstate 580 in Tracy, California
• Interstate 205 in Tracy, California
• Interstate 305 in Sacramento, California (hidden, known as Buisness Loop 80.)
• Interstate 80 in Sacramento, California
• Interstate 505 in Dunnigan, California

Junctions with other interstates in Oregon/Washington (south to north)

• Interstate 105 in Eugene, Oregon
• Interstate 205 (bypass) around Portland, Oregon
• Interstate 405 (bypass) in Portland, Oregon
• Interstate 84 in Portland, Oregon
• Interstate 405 (bypass) in Tukwila, Washington and Lynnwood, Washington
• Interstate 90 in Seattle, Washington

Spur routes

• San Diego, California - I-905 (future)
• Los Angeles, California - I-105,
• Tracy, California - I-205
• Sacramento, California - I-305 (unsigned)
• Zamora, California - I-505
• Eugene, Oregon - I-105
• Tacoma, Washington - I-705

Notes

• Of the existing three-digit Interstate highways, I-105 is the lowest number.
• Interstate 5 is the only Interstate highway to touch both the Canadian and Mexican borders; it may be considered part of the Pan-American Highway, a road that runs from Alaska, United States to Chile. It continues into Vancouver, Canada as BC Provincial Highway 99, and crosses from San Diego to adjacent Tijuana, where it becomes Mexico Route 1D.
• The highest elevation on I-5 is Siskiyou summit, at 4,310 feet, in Oregon, about three miles north of the California border.
• There were plans to build a spur into Salem, Oregon, called I-305, as well as a spur in Portland off of I-405, called I-505, but they were never built. However, a stub of I-505 exists as a long exit ramp to US-30.
• The interstate bisects the University of California, San Diego campus.

References and external links

• http://www.ihoz.com/
• California Highways -- Interstate 5