Another Interstate 580 exists in Reno, Nevada, but is signed only as US 395.

The Interstate 580 number was also used for part of US 75 in Omaha, Nebraska.

Interstate 580 (MacArthur Freeway) in northern California is a heavily traveled, fairly long spur route of Interstate 80 that connects the San Francisco Bay Area to Interstate 5 in the state's Central Valley. The western terminus of I-580 is north of San Francisco in San Rafael, at a junction with U.S. Highway 101. The eastern terminus is with I-5 southeast of Tracy. It was named after General Douglas MacArthur in 1968. Leaving San Rafael, I-580 runs next to the San Quentin State Prison before crossing San Francisco Bay over the Richmond-San Rafael Bridge.

Major cities

• San Rafael
• Richmond
• Albany
• Berkeley
• Emeryville
• Oakland
• San Leandro
• Dublin
• Pleasanton
• Livermore
• Tracy

Intersections with other Interstates

• Joins Interstate 80 in Albany
• Separates from I-80 in Emeryville (junction is also the north terminus of Interstate 880)
  • This intersection is known as the MacArthur Maze
• Interstate 980 (northern terminus of I-980) in Oakland
• Interstate 238 (eastern terminus of I-238) in Castro Valley
• Interstate 680 in Pleasanton
• Interstate 205 (western terminus of I-205) between Livermore and Tracy
• Interstate 5 southeast of Tracy

Notes

On the section of 10-lane freeway that is designated both I-80 and I-580, from Emeryville to Albany, the two routes are running in opposite directions. That is, while a vehicle is physically moving north on the road, it is on both I-80 East and I-580 West.