Interstate 80 California Descriptions

According to signage, I-80 begins at its intersection with U.S. Route 101 in San Francisco. However, the San Francisco Skyway is not part of the Interstate Highway System; the Interstate actually begins at the west end of the Bay Bridge, at the ramps formerly connecting to the Embarcadero Freeway. Thus the first 1.20 miles (1.93 km) of the signed Interstate are not an actual Interstate.

When I-80 was first approved, it was to head north on the Central Freeway (US 101) and west on the never-built Panhandle Freeway, ending at planned I-280 (State Route 1) in Golden Gate Park. A January 1968 amendment moved I-280 to its present alignment, removed Interstate 480, and truncated I-80 to the Embarcadero Freeway (then I-280, formerly I-480).[2] These changes were made on the state level later that year, but Route 80 was only truncated to US 101. (The Central Freeway remained part of US 101, and the Panhandle Freeway became State Route 241. The Panhandle Freeway was later cancelled in the wake of the Freeway Revolts, and the State Route 241 designation has since been reassigned to an unrelated stretch of highway in Orange County) The San Francisco Skyway, which had already been signed as part of I-80, has remained a de facto section of Interstate 80 to the present day and remains listed as part of Route 80 in California.

Sierra Nevada portion

Crossing the Sierra Nevada, I-80 regularly gets snow at higher elevations from fall to spring. The California Department of Transportation (Caltrans) sometimes requires vehicles to use snow tires, snow chains or other traction devices in the mountains during and after snowstorms. Checkpoints are often utilized to enforce chain restrictions prior to entering the Sierra Nevada.

I-80 crosses the Sierra Nevada crest at the Donner Summit in Nevada County at the elevation 2,206 metres (7,240 ft) westbound and 2,203 metres (7,230 ft) eastbound. The pass is generally open year around, is plowed in winter, but may be temporarily closed during the worst snowstorms. Donner Pass is just a couple miles to the south.