Interstate 80 (I-80) is a transcontinental Interstate Highway in the United States, stretching from San Francisco, California, to Teaneck, New Jersey. The segment of I-80 in California runs east from San Francisco across the San Francisco–Oakland Bay Bridge to Oakland, where it turns north and crosses the Carquinez Bridge before turning back northeast through the Sacramento Valley. I-80 then traverses the Sierra Nevada, cresting at Donner Summit, before crossing into the state of Nevada within the Truckee River Canyon. The speed limit is at most along the entire route instead of the state's maximum of as most of the route is in either urban areas or mountainous terrain. I-80 has portions designated as the Eastshore Freeway and Alan S. Hart Freeway.
Throughout California, I-80 was built along the corridor of US Route 40 (US 40), eventually replacing this designation entirely. The prior US 40 corridor itself was built along several historic corridors in California, notably the California Trail and Lincoln Highway. The route has changed from the original plans in San Francisco due to freeway revolts canceling segments of the originally planned alignment. Similarly in Sacramento, the freeway was rerouted around the city after plans to upgrade the original grandfathered route through the city to Interstate Highway standards were canceled.
Route description The entirety of Interstate 80 in California is defined in section 380 of the California Streets and Highways Code as Route 80:
Route 80 is from:(a) Route 101 near Division Street in San Francisco to Route 280 near First Street in San Francisco.(b) Route 280 near First Street in San Francisco to the Nevada state line near Verdi, Nevada, passing near Oakland, via Albany, via Sacramento, passing near Roseville, via Auburn, via Emigrant Gap, via Truckee and via the Truckee River Canyon.
The section of Route 80 defined in subdivision (a) is not considered an Interstate Highway according to the Federal Highway Administration (FHWA)'s route logs, but is still signed as I-80 by Caltrans.
I-80 is recognized as the Dwight D. Eisenhower Highway in the Western United States and a Blue Star Memorial Highway for its entire length. In California, it follows the original corridor of the Lincoln Highway from Sacramento to Reno (with minor deviations near Donner Summit). I-80 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). I-80 is also known as the Dutch Flat and Donner Lake Wagon Road from Emigrant Gap to Donner Lake. The segment of I-80 from Emigrant Gap to Truckee also forms part of the Yuba–Donner Scenic Byway, a National Forest Scenic Byway.
San Francisco Bay Area
According to the California Streets and Highways Code, most maps, and local signs, I-80 begins at the interchange with US 101 in San Francisco. However, federal records place the western terminus of I-80 at the western approach to the San Francisco–Oakland Bay Bridge, at the location of the Fremont Street offramp (previously known as the Terminal Separator Structure that once connected it to the Embarcadero Freeway). The federal and state governments disagree as to whether this westernmost segment of the signed Interstate, known as the San Francisco Skyway or Bayshore Viaduct, is actually part of the Interstate Highway System, although it is consistently shown as I-80 on most maps of San Francisco.
Eastshore Freeway The Eastshore Freeway is a segment of I-80 and I-580 along the northeast shoreline of San Francisco Bay. It runs from the MacArthur Maze interchange just east of the eastern end of the San Francisco–Oakland Bay Bridge to the Carquinez Bridge. I-580 splits from the Eastshore Freeway at an interchange known locally as the "Hoffman Split" in Albany. The section of the Eastshore Freeway between the MacArthur Maze and I-580 (Hoffman) split between Albany is a wrong-way concurrency where the northbound direction is signed as I-80 east and I-580 west, while the southbound direction is signed as westbound I-80 and eastbound I-580. This segment suffers from severe traffic congestion during rush hour due to the merger of three freeways (I-80, I-580, and I-880) at the MacArthur Maze.
The Eastshore Freeway was created in the mid-1950s (construction commenced in 1954, last segment completed May 10, 1960) by reengineering the Eastshore Highway, a thoroughfare constructed in the 1930s (1934–1937) as one of the approaches to the Bay Bridge and designated as part of US 40. The Eastshore Highway began in El Cerrito at an intersection with San Pablo Avenue at Hill Street between Potrero Avenue and Cutting Boulevard, adjacent to the location today of the El Cerrito del Norte station of Bay Area Rapid Transit (BART). It was not a freeway in that access was at intersections with adjoining streets rather than by ramps. The Eastshore Highway ran from El Cerrito to the San Francisco–Oakland Bay Bridge along the same routing as today's freeway, although it was much narrower. A causeway was constructed for this purpose by filling in part of the mudflats along the bayshore. In the stretch from University to Ashby avenues in Berkeley, this resulted in the creation of an artificial lagoon which was developed by the Works Progress Administration (WPA) in the late 1930s as Aquatic Park.
The frontage road along the east side of today's Eastshore Freeway between Buchanan Street in Albany and Hearst Avenue in Berkeley retains the name "Eastshore Highway". The terminal segment of the old Eastshore Highway in El Cerrito between Potrero and San Pablo avenues is today named "Eastshore Boulevard".
Originally, the name "Eastshore Freeway" was also applied to what is today known as the "Nimitz Freeway" (I-880) from the beginning of its construction in 1947. This freeway was dedicated in 1958 to Chester W. Nimitz, and so, for a few years in the 1950s prior, the Eastshore Freeway stretched the entire length of the east shore of San Francisco Bay. Until the late 1960s, the Eastshore Freeway was also designated as part of State Route 17 (SR 17) together with the Nimitz Freeway.
Central Valley This section of I-80 has a top speed of , unlike California's top speed limit of , common in rural freeways. I-80 is a six- to eight-lane freeway with carpool lanes in Fairfield between exit 39A (Red Top Road) and exit 47 (Air Base Parkway).
I-80 has changed routing in the Sacramento area. Currently, the freeway runs on a northern bypass of the city, the Beltline Freeway, that was originally designated I-880. The I-80 routing alignment was moved from a route through Sacramento, now US 50 and I-80 Business (I-80 Bus), after the proposed I-80 replacement of the North Sacramento Freeway was canceled. The Beltline Freeway runs northeast from the junction of I-80 and US 50 in West Sacramento across I-5 to its junction northeast of Sacramento with I-80 Bus (which is SR 51). SR 244 heads east as a short freeway spur from that interchange.
Sierra Nevada 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 set up to enforce chain restrictions on vehicles bound for icy or snowy areas. When chain restrictions are in effect, vehicles must have chains on the driving wheels, except 4WD vehicles with snow tires. Additionally, during the winter season, trucks are required to carry chains whether or not controls are in force.
I-80 crosses the Sierra Nevada crest at Donner Summit (also known as Euer Saddle) at an elevation of westbound and eastbound. The Donner Summit Rest Area is located at this point. The summit is located in Nevada County, California. The pass is generally open year-round; it is plowed in winter but may temporarily close during the worst snowstorms. The older, original US 40/Lincoln Highway route over Donner Pass is about to the south. This highway was replaced as the official trans-Sierra route by I-80 in 1964. Although the current Donner Pass is lower, Euer Saddle was chosen for the Interstate because of more gradual approaches that aided construction to Interstate Highway standards, which do not allow the sharp curves used by the Donner Pass Road. The grade is three to six percent for .
Tolls San Francisco–Oakland Bay Bridge
Tolls are collected only for westbound traffic on the San Francisco–Oakland Bay Bridge's eastern span headed to Yerba Buena Island (those just traveling on the bridge's western span between Yerba Buena Island and the main part of San Francisco are not tolled). All-electronic tolling is used on the bridge, and they can be paid by either a FasTrak transponder or license plate tolling. The high-occupancy vehicle (HOV) lane leading to the bridge requires a car with three or more people.
Carquinez Bridge
Tolls are collected only for eastbound traffic on the Carquinez Bridge headed to Vallejo. All-electronic tolling is also used on this bridge, and they can be paid by either a FasTrak transponder or license plate tolling. The high-occupancy vehicle (HOV) lane leading to the bridge requires a car with three or more people.
Express lanes High-occupancy toll (HOT) lanes along the segment of I-80 between Red Top Road in Fairfield and Leisure Town Road in Vacaville opened on December 16, 2025. Construction on them began in May 2022, and included converting the existing carpool lanes between Red Top Road and Air Base Parkway.
, the HOT lanes' hours of operation is between 5:00 am and 8:00 pm; they are otherwise free and open to all vehicles at other times. Solo drivers are tolled using a congestion pricing system based on the real-time levels of traffic. Two-person carpools are charged 50 percent of the posted toll. Carpools with three or more people and motorcycles are not charged. All tolls are collected using an open road tolling system, and therefore there are no toll booths to receive cash. Each vehicle using the HOT lanes is required to carry a FasTrak Flex transponder with its switch set to indicate the number of the vehicle's occupants (1, 2, or 3+). Solo drivers may also use the FasTrak standard tag without the switch. Drivers without any FasTrak tag will be assessed a toll violation regardless of whether they qualified for free.
In May 2024, the California Transportation Commission approved $105 million for a project that would add HOT lanes between Davis and Sacramento.
History Historic routing
In California I-80 was built along the line of, and eventually replaced, US 40. The US 40 designation was eliminated in the state as part of the 1964 state highway renumbering. US 40 was one of the original California routes designed in 1926, although its west end was in Oakland with US 101E (then SR 17, then I-5W, now I-580/I-880) prior to the San Francisco–Oakland Bay Bridge opening in 1936. An auto ferry ran from Berkeley to San Francisco, signed at the ferry landings for US 40. After the San Francisco–Oakland Bay Bridge's construction, US 40, along with US 50, were extended along the bridge to connect with US 101. The auto ferry service was then discontinued.