Online Resources
Interstate 5
Interstate Guide: I-5: Info on the routing of, improvements to, and average daily traffic numbers for the I-5.
Interstate List: I-5: General facts and notes about the I-5.
Federal Highway Administration: The history of the I-5 and its brethren: "Creating the Interstate System," by Richard F. Weingroff.
California Highways: A state highway hobbyist provides information on California highways.
Northwest Highways: Another state highway hobbyist details several highways in the Pacific Northwest. (last updated Jan. 2003)
Oregon's Highways and Routes: An Oregon state highway hobbyist reports on the I-5 and other roads in his home state.
California highways and roads
AboutVia.com: Links about California transportation.
dmoz.org: Open-source depository of links about California roads and highways.
Oregon highways and roads
AboutVia.com: Links about Oregon transportation.
dmoz.org: Open-source depository of links about Oregon roads and highways.
Washington highways and roads
AboutVia.com: Links about Washington transportation.
dmoz.org: Open-source depository of links about Washington roads and highways.
Facts
The I-5 is 1,375.62 miles long, from San Ysidro, Calif., to Blaine, Wash.
The I-5 reaches 4,183 feet at Tejon Pass in the Tehachapi Mountains.
Last year, traffic on the I-5 in California reached its maximum near Lake Forest Drive in Orange County, averaging 356,000 cars a day.
The U.S.'s busiest international border crossing is located at San Ysidro, Calif., where the I-5 starts.
Parts of I-5 through Orange county contain as many as 22 lanes, if you include auxiliary and carpool lanes.
As it passes by Old Town Sacramento, the I-5 dips lower than the bottom of the nearby Sacramento River.
From Route 10 to Route 99 at the Oregon border, the northern I-5 is a part of "Historic U.S. Highway 99."
One section of I-5 is known as the "Grand Army of the Republic Highway." The last surviving member of this Civil War-era veterans' group died in 1956 at the age of 109.
The "Stone Turnpike Memorial Freeway" segment of the I-5 honors Gold Rush entrepreneurs Elias B. Stone and his family, who built nine bridges across the Sacramento River, 15 bridges across creeks and gulches, and a 43-mile road notched into Sacramento River Canyon's walls. Despite a winter storm that destroyed most of their work, the Stones rebuilt.
In Oregon, part of the I-5 had been a toll road that once charged 25 cents for men on foot or horseback. The road was bought from its shotgun-toting owner in the early 1900's for $1,000.
The I-5 was originally approved for construction in 1947, along with the I-505 and I-580, but the three-digit routes didn't get their signs until as late as 1965.
