Interstate 8 (abbreviated I-8) is an Interstate highway in the southwestern United States. It runs from the southern edge of Mission Bay at Sunset Cliffs Blvd. in San Diego, California. In California, especially from eastern San Diego County to points east, Interstate 8 runs very close to the United States-Mexico border. At points in eastern Imperial County, the border is no more than two miles (3 km) south of the Interstate.
I-8 within the Mountain Springs/In Ko Pah grade has one of the widest medians on the entire Interstate highway system. In places, the median is over 1.5 miles wide.

Arizona

Interstate 5 in San Diego, California
Interstate 805 in San Diego, California
Interstate 15 in San Diego, California
Interstate 10 in Casa Grande, Arizona