California State Route 15 is an approximately 6.13-mile portion of the Archie Moore Memorial Freeway and Escondido Freeway in the city of San Diego. California State Route 15 beings at Interstate 5 and ends at Interstate 8. California State Route 15 functionally acts as an extension of Interstate 15 south of Interstate 8 to Interstate 5. California State Route 15 exists due to the Archie Moore Memorial Freeway south of Interstate 805 not fully meeting Interstate standards. California State Route 15 was created during 1969 as a renumbering of the original California State Route 103. During 1984 California State Route 15 was approved by the Federal Highway Administration to become a non-chargeable part of Interstate 15 once it meets Interstate design standards.
Part 1; the general history of the original California State Route 15
The current California State Route 15 is the second time the designation has been used. The original California State Route 15 was tied heavily to Legislative Route Number 167 (LRN 167) and the future corridor of the Long Beach Freeway. As originally defined in 1933 LRN 167 ended at LRN 26 (then US Route 60 and later also US Route 99-70) in Monterey Park. The initial run of Sign State Routes was announced in the August 1934 California Highways & Public Works. California State Route 15 was defined as following LRN 167 to a terminus US Routes 99-60-70/LRN 26 in Monterey Park via Atlantic Boulevard (later Atlantic Avenue).
Part 2; the history of the current California State Route 15
1. LRN 241 near north city limits of National City to LRN 2 (US Route 101/Interstate 5) 2. LRN 2 to LRN 77 (US Route 395) near United States Naval Air Station, Miramar
LRN 283 appears for the first time on the 1960 Division of Highways Map.
The July/August 1960 California Highways & Public Works discussed segment two of LRN 283. LRN 283 is noted in the article to not have a formal route adoption by the California Highway Commission between US Route 101/LRN 2 and US Route 395/LRN 77. The article references the city of San Diego adopting Wabash Boulevard, 40th Street and Ward Road as major highway corridor following World War II. The Wabash Boulevard/California State Route 94 interchange is shown to have been constructed by the city of San Diego prior to becoming part of LRN 283. A portion of Ward Road between Monroe Street to US Route 80 is noted to be nearing completion as a four-lane expressway. The segment north of US Route 80 to US Route 395 is noted to be under construction and financed. Continued development of LRN 283 is noted to be a cooperative between the Division of Highways, city of San Diego and Federal Aid Programs.
Part 3; RoadwayWiz on California State Route 15
During August 2020 Dan Murphy of RoadwayWiz featured a real-time drive along California State Route 15 southbound from Interstate 8 to Interstate 5.