Interstate 380

Home » Guides » California Highways » Interstate 380

Interstate 380 is the Quentin L. Kopp (formerly Gaspar de Portola) Freeway, a short connector between Interstate 280 (Father Junipero Serra Freeway) in San Bruno and U.S. 101 (Bayshore Freeway). The east end provides direct connections with San Francisco International Airport (SFO).

A long term proposal for the California State Route 380 freeway outlined an extension of the route west from I-280 to SR 1 near Pacifica. Obstacles against this controversial highway included lengthy environmental review, community opposition, earthquake considerations due to the route passing over the San Andreas Fault and others. Exit numbers for I-380 start at 5, factoring in the unbuilt extension west to SR 1.

I-380 was established as an Interstate highway in December 1968 per the Federal Highway Act of that year. Subsequent actions by the state modified the Streets and Highways Code in 1969 with former SR 186 redesignated as Interstate 380.1

Southern Crossing

The east end of I-380 was suggested by some as a potential western terminus of a new trans-San Francisco Bay bridge. Proposals for an additional crossing, including the Southern Crossing at Hunters Point in San Francisco, arose between the 1940s and 1970s.2

Pushed by Senator Dianne Feinstein, D-California initially in 2000, ideas for a Southern Crossing continued over the ensuing two decades. A two-year study released on April 3, 2002 concluded that building a new span from I-380 on the Peninsula east to Interstate 238 in San Leandro would cost $8.2 billion.3 A subsequent study in 2012 estimated that a bridge carrying both vehicles and transit would cost $12.4 billion. Feinstein and Representative Mark DeSaulnier, D-Concord advocated a new crossing, referencing increased congestion on the San Francisco-Bay Bridge (I-80) and intolerable traffic demands on streets and mass transit, in a letter issued to the Metropolitan Transportation Commission (MTC) on December 6, 2017.2 The MTC did not commit to a new bay-crossing study at the time, citing that it was not on the list of projects approved by Regional Measure 3, a funding ballot that eventually passed on June 5, 2018. Paid for by a $3 toll increase on seven state-owned bridges, Regional Measure 3 will raise an estimated $4.45 billion over a ten year period for capitol projects. The bulk of money will fund transit projects, with 34.4 percent going toward highway improvements or other road projects.4

Interstate 380 East
Following Exit 43 A from I-280 south onto Interstate 380 east. Unused overpasses span the two lane ramp ahead. The bridges were built in anticipation for the unconstructed extension of the freeway west to SR 1. 07/11/18
The first exit along Interstate 380 eastbound is for SR 82 (El Camino Real) north to the city of South San Francisco and south to the city of San Bruno. 07/11/18
Interstate 380 is designated as the Quentin L. Kopp Freeway for its entire length. Kopp was a former member of the Board of Supervisors for the city and county of San Francisco and then was a judge in San Mateo County. Kopp retired in 2004. 07/11/18
Entering the six-ramp parclo interchange (Exit 5) with SR 82 (El Camino Real) on I-380 east. Extending nearly the length of the Peninsula from San Jose to San Francisco, SR 82 is old U.S. 101. The Bayshore Freeway to the east was previously U.S. 101 Bypass, excluding a few segments. 07/11/18
Three lanes advance east along Interstate 390 to North Access Road, the rental car return and long term parking for San Francisco International Airport (SFO). 07/11/18
An auxiliary lane opens along Interstate 380 east from El Camino Real to Exit 6 A for U.S. 101 (Bayshore Freeway) south. 07/11/18
Exit 6 A departs from I-380 east for U.S. 101 south to the main entrance for San Francisco International Airport (SFO) and San Jose. The succeeding two lane flyover connects with U.S. 101 north to San Francisco. 07/11/18
Exit 6 B lowers between the southbound mainline of U.S. 101 and a collector distributor roadway ahead of the three wye interchange with Airport Access Road to the SFO passenger terminal. 11/26/04
Traffic taking Exit 6 B partitions with slip ramps joining the c/d roadway to SFO Airport and U.S. 101 south to Millbrae, San Mateo and Redwood City. 11/26/04
Continuing east through the systems interchange with the Bayshore Freeway, Interstate 380 separates with Exit 6 B for U.S. 101 north. 07/11/18
Interstate 380 west concludes where Exit 7 separates for S Airport Boulevard and N Access Road to the North Cargo Area at SFO Airport. 07/11/18
Flyovers linking I-380 and U.S. 101. 07/11/18
I-380 ends at a signalized intersection joining Exit 7 and N Access Road. 07/11/18
N Access Road leads west back to S Airport Boulevard and east along the perimeter of SFO Airport. 07/11/18
Interstate 380 West
Interstate 380 commences west from a signalized intersection with N Access Road at the North Cargo Area of San Francisco International Airport (SFO). 07/11/18
Two lanes ascend from N Access Road onto Interstate 380 west across S Airport Boulevard. 07/11/18
Interstate 380 (Kopp Freeway) enters the systems interchange (Exit 6) with U.S. 101 (Bayshore Freeway) west from N Access Road. 07/11/18
Exit 6 partitions onto flyovers for U.S. 101 (Bayshore Freeway) north to San Francisco and south to San Jose. 07/11/18
Connecting the Long Term Parking facilities of San Francisco International Airport (SFO) with both the Kopp Freeway west and U.S. 101 north, an entrance ramp rises onto I-380 west from the intersection of N Access Road and S Airport Road. 03/26/16
Flyover ramps for U.S. 101 converge above the westbound mainline of Interstate 380. 07/11/18
Succeeding lane drops leave a single lane for I-380 west ahead of the entrance ramps from the Bayshore Freeway. 07/11/18
Viewing Interstate 380 from the two lane flyover linking SFO Airport and U.S. 101 with the Kopp Freeway westbound. 11/26/04
Interstate 380 westbound expands to six lanes with the advent of traffic from U.S. 101. Two lanes depart at Exit 5 for SR 82 (El Camino Real) to The Shops at Tanforan mall and the city of San Bruno. 07/11/18
SR 82 (El Camino Real) runs between the I-280 and U.S. 101 corridors north to San Francisco and south to San Jose. 07/11/18
Historically the arterial route along SR 82 was the first alignment of U.S. 101 along the Peninsula. 07/11/18
Passing over El Camino Real, a supplemental sign references the forthcoming ramp (Exit 5 B) to Interstate 280 north for Daly City and SR 1 south to Pacifica. 07/11/18
The lone confirming shield for Interstate 380 west stands beyond the entrance ramp from SR 82. 07/11/18
Four lanes continue west along I-380 to the directional T interchange (Exits 5 B/A) with Interstate 280. A green overlay likely covered "Exit One Mile" or "Right Lanes".5 07/11/18
A stub end of the freeway mainline appears within the median as traffic defaults onto high speed ramps for Interstate 280. A two lane flyover joins I-280 (Father Junipero Serra Freeway) south to Cupertino and San Jose. 07/11/18
Three lanes connect the west end of I-380 with Interstate 280 north. The bulk of traffic headed to San Francisco eventually leaves I-280 north for SR 1 (19th Avenue), which is the best north to south corridor through the city. 07/11/18
Interstate 380 scenes
Airport Boulevard leads north from San Bruno Avenue in unincorporated San Mateo County adjacent to San Francisco International Airport (SFO). The four lane arterial connects the Long Term Parking garage for the airport with the systems interchange joining Interstate 380 and U.S. 101 (Bayshore Freeway). 11/26/04
A direct ramp links Airport Boulevard with Interstate 380 west to I-280 (Junipero Serra Freeway) to San Francisco and the Golden Gate Bridge and points north via SR 1. 11/26/04
Northbound Airport Boulevard continues beyond the westbound on-ramp for I-380 and North Access Road east into the city of South San Francisco. The distant Sign Hill embedds the city's name. 11/26/04
Reflective signs above Airport Boulevard at North Access Road were newly installed in 2004. 11/26/04
North Access Road circles east from Airport Boulevard to intersect the westbound beginning of I-380. The frontage road allows motorists to connect with the northbound on-ramp for U.S. 101. 11/26/04
North Access Road hooks south to intersect the east end of I-380 and its continuation east to the SFO Airport north cargo area and U.S. Coast Guard Air Station San Francisco. 11/26/04
Departing the passenger terminals of San Francisco International Airport (SFO), Airport Acess Road partitions into ramps for U.S. 101 (Bayshore Freeway) and a lengthy distributor roadway to both Interstate 380 west and San Bruno Avenue. 03/19/07
Departing the passenger terminals of San Francisco International Airport (SFO), Airport Access Road partitions into ramps for U.S. 101 (Bayshore Freeway) and a lengthy distributor roadway to both Interstate 380 west and San Bruno Avenue. 03/19/07
Caltrans standard signs precede the Airport Access Road ramp split for U.S. 101 south to San Jose, U.S. 101 north to San Francisco and the distributor roadway for I-380 west to San Bruno and Interstate 280. 03/19/07

  1. California Highways: Route 380 by Daniel Faigin
  2. "Feinstein: Traffic is terrible. Build a new bay bridge." San Francisco Gate (CA), December 6, 2017.
  3. "New bridge? Yeah, right / Southern Crossing, transbay tube would cost at least $8 billion, study says." San Francisco Chronicle (CA), April 3, 2002.
  4. "Bay Area voters OK higher bridge tolls to curb traffic." The Mercury News (San Jose, CA), June 5, 2018.
  5. Newton-John, Mark.

Photo Credits:

11/26/04, 03/19/07, 03/26/16, 07/11/18 by AARoads

Connect with:
Interstate 280
U.S. 101

Page Updated 07-14-2023.

Go to Top