America's First Freeway

However, this route here is an anomaly, because as the sign hints the highway we exit onto isn't CA 110: it's actually unsigned CA 710, the northernmost discontinuous segment of what was supposed to be Interstate 710.

Although I-710 is the Long Beach Freeway, that designation ends in Alhambra where the current freeway does, and its ancestor Los Angeles River Freeway (then signed CA 15) was never intended to go further north than the Santa Ana Fwy (now I-5). In 1961 the Calfornia Division of Highways started exploring extension options north of Interstate 10 and adopted a routing in 1964. At this point during the California Great Renumbering the 15 route number was assigned to Interstate 15 and the Long Beach Fwy became Route 7.

The first extension in 1965 brought the freeway to its present terminus at Valley Blvd and Caltrans continued the purchase of further right-of-way including several hundred homes. However, lawsuits were first filed in 1973 based on the new NEPA and CEQA environmental policies and tied the project up in court for years despite the Federal Highway Administration approving it as non-chargeable Interstate in 1983. Nonetheless, Caltrans still managed to complete the northern Pasadena terminus of future Interstate 710 in 1975, the alignment we will drive here.

In 1984, Caltrans obtained AASHTO approval to convert the Long Beach Fwy from CA 7 to I-710, though other marks of the old number still remain. Public opposition to the various alternative surface routings to connect to the 1975 northern stub nevertheless mounted rapidly, with over 20 variations being entertained, and in 1999 a preliminary injunction prevented Caltrans from proceeding further with the surface project. Although a tunnel alternative was first proposed in 2004, years of study amidst local criticism eventually concluded tunneling, albeit technically feasible, would be unacceptably expensive, potentially traversed underground faults and wouldn't address concerns over air quality. In 2018, the entire project was abandoned for local street improvements instead and the routing between Alhambra and Pasadena will be officially deleted from the state highway code in 2024. Caltrans has been slowly divesting themselves of the right-of-way acquired back in the 1960s, but the Alhambra and Pasadena stubs remain state highway to this day and are the last pieces of the failed expansion that are still extant.

This was the Pasadena Fwy from 1954 to 2010. We'll have much more to say about it in Part 3.

The northbound alignment is the subject of the next Part.

We now officially begin the Interstate-shield portion, but we'll fast-forward to the southern terminus in San Pedro and loop around in the next Part.