in Santa Monica to SR 39 in Buena Park.

[citation needed] Between Santa Monica and Los Angeles, it was later replaced by the Santa Monica Freeway, and added to the Interstate Highway System on September 15, 1955.

[citation needed] The highway originally traveled along 10th Street in Los Angeles, but as Olympic Boulevard was built out to the west and east, it was aligned to that.

East of Los Angeles, the highway turned southeast along the Anaheim Telegraph Road, which it followed into Santa Fe Springs.

The portion east of Downtown Los Angeles was eventually deleted from the system as redundant to US 101 Byp.