Business Loop I-8 - Winterhaven, California and Yuma, Arizona

A well signed route, Business Loop I-8 (Winterhaven Drive) arcs north from Interstate 8 through the community of Winterhaven between Exits 170 and 173. The route continues south across the Colorado River to 4th Avenue and the Yuma business district. Two miles south of U.S. 95 (16th Street), Business Loop I-8 curves east onto 32nd Street by Yuma International Airport (YUM) to reconvene with I-8 at Exit 9.

All of Business Loop I-8 between Winterhaven and Yuma follows the old alignment of U.S. 80. The California portion of the business route is not referenced in the 1991 state signing log. The 1998 Arizona State Highway System Log listed the Yuma portion of Business Loop I-8 as 11.93 miles. The Arizona portion varies between state and city maintenance. Sections along 4th Avenue and 32nd Street were transferred to the city of Yuma in September or November 2010 while the eastern extent between mileposts 11.50 to 12.66 was transferred to the city in September 2003.