Interstate 880 (California)

Interstate 880 (I-880) is a north–south auxiliary Interstate Highway in the San Francisco Bay Area of Northern California. It runs from I-280 and State Route 17 (SR 17) in San Jose to I-80 and I-580 in Oakland, running parallel to the eastern shore of San Francisco Bay. For most of its route, I-880 is officially known as the Nimitz Freeway, after World War II fleet admiral Chester W. Nimitz, who retired to the Bay Area. The northernmost five miles (8.0 km) is also commonly referred to as the Cypress Freeway, after the former alignment of the freeway and its subsequent replacement.

The entirety of I-880 is defined in section 625, subdivision (a) of the California Streets and Highways Code as Route 880, and that the highway is from "Route 280 to Route 80 in Oakland".

In addition, section 325 subdivision (b), last amended by the California State Legislature in 2001, permits the state to relinquish the former right-of-way of Route 880 located along the now-demolished Cypress Street Viaduct between 8th and 32nd streets to the City of Oakland. The entirety of I-880 is considered a "non-chargeable" Interstate Highway (built without federal Interstate completion funds per 23 U.S.C. § 103(c)(4)(A)) according to the Federal Highway Administration (FHWA)'s route logs.

The southern terminus of I-880 is at its interchange with I-280 and SR 17 in San Jose. From there, it heads roughly northeast past San Jose International Airport to US Route 101 (US 101). The Nimitz Freeway then turns northwest, running parallel to the southeastern shore of San Francisco Bay, connecting the cities of Milpitas, Fremont, Newark, Union City, Hayward, and San Leandro before reaching Oakland. In Oakland, I-880 passes by Oakland International Airport, Oakland Coliseum, the Port of Oakland, and Downtown Oakland. The northern terminus of I-880 is in Oakland at the junction with I-80 and I-580 (known as the MacArthur Maze), near the eastern approach of the San Francisco–Oakland Bay Bridge.

I-880 between I-238 in San Leandro and the MacArthur Maze is used as the main truck route; trucks over 4.5 short tons (4.1 t; 4.0 long tons) are prohibited through Oakland on I-580.

I-880 is part of the California Freeway and Expressway System and is part of the National Highway System, a network of highways that are considered essential to the country's economy, defense, and mobility by the Federal Highway Administration (FHWA). Officially, the Nimitz Freeway designation is Route 880 from Route 101 to Route 80, as named by Senate Concurrent Resolution 23, Chapter 84 in 1958.

Since the late 1990s, an infamous misconception for certain commuters and businesses in San Jose is that I-880 extends from I-280 to SR 85 in Los Gatos (which would extend the length to 50 miles [80 km]).^{[citation needed]}

High-occupancy toll (HOT) lanes along I-880 between the Milpitas–Fremont line at Dixon Landing Road and Lewelling Boulevard in San Lorenzo opened in October 2020. The southbound express lanes extend north to Hegenberger Road in Oakland and south to SR 237 in Milpitas.