Pre-1964 Legislative Route 242 (California)

Interstate 80
Route information
Defined by
Maintained by Caltrans
Length:	205.07 mi (330.03 km)
History:	Proposed August 7, 1947 by FHWA Federally designated June 26, 1956 Signed July 1, 1964 by Caltrans
Restrictions:	No flammable tank vehicles or explosives on the Bay Bridge
Major junctions
West end:	US 101 in San Francisco
	I-580 / I-880 in Oakland SR 4 in Hercules I-780 in Vallejo I-680 in Fairfield I-505 in Vacaville US 50 / I-80 Bus. in West Sacramento I-5 / SR 99 in Sacramento I-80 Bus. in Sacramento SR 49 in Auburn SR 89 in Truckee
East end:	I‑80 at Nevada state line
Highway system
Interstate Highway System Main Auxiliary Suffixed Business Future State highways in California Interstate U.S. State Pre-1964 History Unconstructed Deleted Freeway Scenic ← SR 79 US 80 →

U.S. Route 40
Location:	San Francisco–Nevada state line
Existed:	1926–1964

Interstate 880
Location:	West Sacramento–Sacramento
Existed:	1971–1983

Interstate 80 (I-80) is a major east–west route of the Interstate Highway System, running between the U.S. states of California and New York. The highway has its western terminus in San Francisco. 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 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 65 miles per hour (105 km/h) along the entire route instead of the state's maximum of 70 mph (110 km/h) and 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 U.S. 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 re-routed around the city after plans to upgrade the original grandfathered route through the city to Interstate highway standards were cancelled.

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Wikipedia