In the U.S. state of California, Interstate 80 (I-80), a major east–west route of the Interstate Highway System, has its western terminus (ending point) in San Francisco, California, United States. From there it heads east across the Bay Bridge to Oakland, where it turns north and crosses the Carquinez Bridge before turning back northeast through the Sacramento Valley. I-80 then goes northeast and east over the Sierra Nevada mountain range before crossing into the state of Nevada within the Truckee (River) Canyon. The speed limit is instead of the state's maximum of since the road passes exclusively through urban and mountainous areas in California.