Road builders in 1946 were busy widening what was then U.S. 101 through Camp Pendleton, the U.S. Marine Corps base in the northwestern corner of San Diego County.
Running north from Oceanside to the Orange County border, the project eliminated one of the last spots in the region where 101 was just two lanes… one lane north, one lane south, and that dreaded “suicide lane” in the middle that was used for passing.
“The unprecedented increase in population of the San Diego metropolitan area, due to defense activities as well as natural growth, and also the establishment of Camp Joseph H. Pendleton, the largest Marine base in the country, has severely taxed what is popularly known as “El Camino Real,” State Route 2 (U.S. 101), the main coast highway,
particularly from Oceanside north,” wrote Earl E. Sorenson, District Construction Engineer in California Highways and Public Works magazine, now preserved at archive.org.
The story is mostly about the construction methods used, including details on a new machine that cut expansion joints in the concrete.
Parts of this project’s work are still visible after today’s Interstate 5 crosses over the railroad tracks north of Las Pulgas Road. Today, it’s used as a bicycle path.
Explore old U.S. 101 south of this area in the Quintessential California chapter of my Joyrides Around San Diego. It makes a perfect San Diego day trip.