The history of the original California State Route 117
What was to become California State Route 117 was added to the State Highway System as part of 1956 Legislative Chapter 63. Legislative Chapter 63 defined Legislative Route Number 237 (LRN 237) as:
"Junipero Serra Boulevard as it exists and as it was constructed by Joint Highway District No. 10 from its junction with LRN 56 (California State Route 1) in Daly City to the present terminus of said highway in the City of San Bruno. Upon the effective date of this section, the Joint Highway District No. 10 shall be dissolved in accordance with the provisions of Chapter 20 of Part 1 of Division 16 of the Streets and Highway Code and all property, assets, and liabilities of said district shall become property of the State."
Junipero Serra Boulevard appears as LRN 237 for the first time on the 1957 Division of Highways Map.
The March/April 1957 California Highways & Public Works announced the addition of LRN 237 to the State Highway System. Upon Joint Highway District Number 10 being dissolved during July 1956 the entirety of Junipero Boulevard was adopted by the California Highway Commission and declared designated a future freeway corridor (the Junipero Serra Freeway).
The March/April 1959 California Highways & Public Works announced the planned Junipero Serra Freeway from the end of Junipero Serra Boulevard/LRN 237 near San Bruno Avenue and Saratoga Avenue in Santa Clara had been adopted by the California Highway Commission as part of LRN 239 (defined in 1957) on July 23, 1958. The prospective relocation of LRN 237 onto an adopted freeway corridor is noted to be in the process of study.
The southern terminus of LRN 237 is shown connected to the adopted Junipero Serra Freeway corridor of LRN 239 on 1960 Division of Highways Map.
The March/April 1960 California Highways & Public Works announced the relocation LRN 237 was discussed at a series of public hearings during January 1960.
The January/February 1962 California Highways & Public Works discussed the history of Joint Highway District Number 10. Joint Highway District Number 10 was created during 1928 as a cooperative between San Francisco County and San Mateo County. The purpose of the district was to ultimately construct a new arterial highway from San Franscico south to San Jose. By 1939 the district had located an alignment for Junipero Serra Boulevard as far south as Santa Clara County line. Junipero Serra Boulevard had constructed to Crystal Springs Road by 1952 via right-of-way largely obtained in Millbrae. Joint Highway District Number 10 began to encounter financial difficulties and issues finding a suitable alignment which led to Junipero Serra Boulevard being turned over to the state as LRN 237 during 1956. The general routing of the Junipero Serra Freeway (Interstate 280) following LRN 237/existing Junipero Serra Boulevard north of San Bruno is noted to have been adopted by the California Highway Commission during 1960.
As part of the 1964 State Highway Renumbering what had been LRN 237 along Junipero Serra Boulevard was defined as California State Route 117. California State Route 117 was defined as "Crystal Springs Road in the city of San Bruno northerly to Route 280 in Daly City." The adopted Junipero Serra Freeway corridor north of San Bruno was defined as part of legislative definition of Interstate 280. California State Route 117 appears for the first time on the 1964 Division of Highways Map.
The original California State Route 117 was deleted by way of 1965 Legislative Chapter 1372. Junipero Serra Boulevard north of San Bruno was transferred legislatively as Route 280 which functioned as a placeholder connection for Interstate 280. Junipero Serra Boulevard north of San Bruno can be seen as part of Route 280 on the 1966 Division of Highways Map. Junipero Serra Boulevard was relinquished from the State Highway System during 1970 following the completion of Interstate 280 on the Junipero Serra Freeway north of San Bruno.