Linking I-5/10, U.S. 101, and California State Route 10 (former I-110) north of Downtown Los Angeles, Interstate 105 was previously commissioned along the Santa Ana Freeway between 1964 and 1968. I-105, then I-110 and U.S. 101 converged at an exchange east of the Los Angeles River and Mission Road. The original Interstate 105 was subsequently decommissioned, and that portion of the Santa Ana Freeway remains as the southernmost extent of U.S. 101.
Interstate 105 was revived several years later as the designation for the proposed Century Freeway. A controversial route, protests against the freeway from adjacent community members arose throughout the 1970s and 1980s. Construction finally commenced on I-105 in 1982. Replacing parallel SR 42 (Manchester Avenue), I-105 was originally slated to meet Interstate 5 in Norwalk, but that extension was deleted from plans. The City of Norwalk considered the freeway to be divisive, and many would argue that the effectiveness of Interstate 105 as a primary east-west freeway was undercut by Norwalk’s action preventing construction within its boundaries.
Another early proposal outlined extending Interstate 105 east beyond I-5 to SR 90 (Richard M. Nixon Freeway) in Orange County. Such a freeway was squashed by public outcry, but the extension remained on the official California state map as a proposed freeway corridor along unconstructed SR 90.
Even after it was completed, some problems continued to plague Interstate 105. Since the freeway was constructed below-grade, portions of the roadway sunk between I-605 and I-710. This section of freeway lies between the San Gabriel River (which parallels I-605) and the Los Angeles River (near I-710). As a result of the pavement sinking and cracking, the freeway required premature repairs. A state of California audit report issued in 1999 scrutinized the California Department of Transportation (Caltrans) for not adequately testing the soil and groundwater conditions prior to construction.1
For more on the Century (Glenn Anderson) Freeway, see Interstate 105 (Daniel Faigin) and In Our Path: Interstate 105 (Jeff Gates).