Rosecrans Avenue is a major west-east thoroughfare in Los Angeles and Orange Counties, California, USA. It has a total length of 27.5 miles (44.3 km). The street is named after U.S. Union General William S. Rosecrans, who purchased 13,000 acres (5,300 ha) of Rancho Sausal Redondo southwest of Los Angeles in 1869. Rosecrans Avenue was originally named Drexel Avenue, and ran through the Rosecrans Rancho which is part of modern-day Gardena.

Route 110, consisting of State Route 110 (SR 110) and Interstate 110 (I-110), is a state and auxiliary Interstate Highway in the Los Angeles metropolitan area of the US state of California. The entire route connects San Pedro and the Port of Los Angeles with Downtown Los Angeles and Pasadena. The southern segment from San Pedro to I-10 in downtown Los Angeles is signed as I-110, while the northern segment to Pasadena is signed as SR 110. The entire length of I-110, as well as SR 110 south of the Four Level Interchange with US Route 101 (US 101), is the Harbor Freeway, and SR 110 north from US 101 to Pasadena is the historic Arroyo Seco Parkway, the first freeway in the western United States.