Interstate 380 (California)
Interstate 380 is a short east-west auxiliary Interstate Highway in the San Francisco Bay Area of Northern California, connecting I-280 in San Bruno to US Route 101 near San Francisco International Airport. The highway primarily consists of only three intersections: I-280, State Route 82, and US 101. Like the nearby I-280, I-380 never connects to I-80, its parent Interstate Highway. However, there is no rule that says that spur routes need to do so.
I-380 is officially known as the Quentin L. Kopp Freeway, named after the prominent California state senator from San Mateo County. This highway was previously named the Portola Freeway to honor the 18th-century Spanish explorer Gaspar de Portolá, whose expedition in 1769–1770 discovered the San Francisco Bay, from a viewpoint on the Sweeney Ridge located between San Bruno and Pacifica.
Route description
The entirety of I-380 is defined in section 608 of the California Streets and Highways Code as Route 380, and that the highway is from:Route 1 near Pacifica to Route 280 in San Bruno.
Route 280 in San Bruno to Route 101 in the vicinity of the San Francisco International Airport.
The segment defined in subdivision remains unconstructed, and is not included in the Federal Highway Administration 's Interstate Highway route logs.
I-380 begins at a junction with I-280 in San Bruno. This junction was only partially built, with room to accommodate a proposed freeway extension west toward SR 1. The freeway itself lacks overhead guide signs mentioning I-380. It then travels east through the city of San Bruno, intersecting with SR 82 before reaching US 101.
At its terminus at US 101, the mainline lanes of I-380 continue to North Access Road. The ramps to and from southbound US 101 provide connections to collector–distributor roads leading directly to San Francisco International Airport, allowing traffic between the Interstate and the airport to avoid merging with the main traffic lanes of US 101.
I-380 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.