 In California, the former western branch of Interstate 5 (the northern end of the spur into the Bay Area) connecting Interstate 80 out of Vacaville to near Dunnigan, previously known as Interstate 5W, was renamed Interstate 505.Interstate 580 running between I-5 and I-80 was also once designated 5W; what is now I-5 (the stretch that runs through Sacramento) had been originally designated Interstate 5E.The term "Golden State Highway" was the popular name for U.S. Route 99, stretching from Mexico to Canada through the length of California.