US 40 and US 50 both followed the Bay Bridge and the routes split on what is the present day MacArthur Maze in Oakland, California. US 50 continued southeast on present-day I-580 to Stockton and US 40 closely followed the route of present-day I-80. When reaching Sacramento, California, US 40 and US 50 rejoined, US 50 running concurrently with former US 99 from Stockton to Sacramento. US 40 then again split with US 50 in Downtown Sacramento and closely followed the route of present-day Business I-80, which was I-80 from 1957 to 1981, when I-80 was realigned along former I-880, routing along what was then the outskirts of Sacramento. US 40 then closely followed I-80 through the Sierra Nevada Range into Nevada.