Business Loop Interstate 8 is a business loop route that diverges from Interstate 8 in El Centro, California to pass through the downtown area. Business Interstate 8 originates and terminates with I-8 and acts as a direct link to El Centro as I-8 bypasses the downtown area.
Business Interstate 8's path through El Centro traces roughly three sides of a rectangle with I-8 constituting the fourth side. BUS-8 begins at its western terminus with I-8 by going north along Imperial Avenue. When BUS-8 reaches the intersection of Adams Avenue it turns east along that road. Along this stretch, BUS-8 is joined by State Route 86 which approaches from the north along Imperial Ave, and by Imperial County Route S80 which approaches from the west along Adams Avenue. The three routes continue joined as Adams Avenue ends and turns south along Fourth Avenue where S80 then turns to continue east. BUS-8 and SR-86 continue south running concurrent until BUS-8 reaches its eastern terminus with I-8.
Only the portion of BL-8 that runs concurrently with SR 86 is maintained by the state. Along its concurrency with SR-86, BUS-8 is designated as part of the Juan Bautista de Anza National Historic Trail.