Runs from I-5 in San Diego (as SR-15) to the Nevada State Line in Ivanpah Valley near Primm eventually ending at the Canadian border near Sweetgrass, Montana
I-15 starts at I-8 near City Heights in San Diego.
I-15 runs through varied country. It skirts the LA area through Corona, Norco, and Ontario passing through mostly farming lands. The segment from SR-91 to SR-60 wasn’t completed until 1989. Traffic had to detour onto either then SR-215 or TEMP I-15 – Hamner Avenue (former SR-31). High winds are a major problem for this route in the Cajon Pass area, as well as outbound traffic on weekends. Backups can extend from SR-210 north to I-215 on busy weekends.