The Harbor Freeway is one of the principal north-south freeways in Los Angeles County, California. Signed as Interstate 110 (abbreviated I-110) for its entire length, it runs from Gaffey Street in San Pedro to the Santa Monica Freeway (Interstate 10) south of downtown Los Angeles, where it turns into the Pasadena Freeway and becomes signed as California State Highway 110. The Harbor Transitway is a grade-separated bus and high-occupancy vehicle corridor in the median running between State Route 91 (Gardena Freeway) and the south side of downtown Los Angeles.

Interstate 110 (abbreviated I-110) is an unsigned 0.92 mile spur route in El Paso extending from Interstate 10 south to State Highway Loop 375 at the Rio Grande. The route is signed as U.S. Route 54, which also continues north of Interstate 10.

Interstate 110 (abbreviated I-110) is an auxiliary route of the Interstate Highway System in Pensacola, Florida, running south from Interstate 10 to U.S. Highway 98. Carrying the hidden Florida Department of Transportation designation of State Road 8A, I-110 is also known as the Reubin O'Donovan Askew Parkway, in honor of the former governor of Florida who is also a Pensacola native.