The history of US 80 and I-8 in California

[Max Rockatansky]

Considering this took a solid twenty hours to research I'm hoping that I don't have to write another monster article like this again.  That said, there is some interesting takeaways:

-  It seems US Route 80 was extended to Point Loma after Camino del Rio and Alvarado Canyon Road were annexed into Legislative Route Number 12.
-  Much of what became I-8 in San Diego was planned way back in 1934.
-  The Mountain Springs Grade became a franchise toll road during the 1870s. 
-  For unclear reasons California never bothered to submit an application to extend I-8 west of Interstate 5.  What is signed as I-8 west of I-5 isn't on the FHWA mileage log.
-  I knew about the Division of Highways trying to swap the numbers for I-8 and I-10, but I figured it was worth highlighting here.

Anyways, here is the article header and link:

"The historic corridor of US Route 80 and Interstate 8 through the borderlands of southern California share a largely mutual history.  Both highways originated in the city of San Diego and departed the state at the Colorado River into Yuma, Arizona.  Both highways share numerous famous geographical components such as the Mountain Springs Grade and Algodones Sand Dunes.  This article serves as a comprehensive history of the combined US Route 80/Interstate 8 corridor in California from the tolled stage route era of the nineteenth century to the development of the modern freeway. 

The blog cover photo features US Route 80 along the Mountains Springs Grade through In-Ko-Pah Gorge during late 1920s.  This photo is part of the Caltrans McCurry Collection."

https://www.gribblenation.org/2024/06/the-history-of-us-route-80-and.html

[The Ghostbuster]

Are there any Historical US 80 signs along US 80's former alignment through California?

[Max Rockatansky]

I'm not aware of any.  But there is County Route S80 and lots of roads signed as "Old Highway 80."

[pderocco]

There are plenty in San Diego County, including San Diego, La Mesa, El Cajon, Alpine, Pine Valley, and all the way out to the In-Ko-Pah Park Rd merge into I-8. You can find them in GSV, mostly placed so you see them when you get onto the road from another major road. I don't think I've seen any in Imperial County, though. Here's one for your viewing pleasure:
https://maps.app.goo.gl/idsuJMh5xjG2CuTg7

[ARMOURERERIC]

Are there any Historical US 80 signs along US 80's former alignment through California?

I lived in socal 1996-2016, I recall brown historic 80 Shields in El Cajon and La Mesa.  Also,I lived in Boulevard 2009-16 and was almost a daily driver from in ko pa to golden acorn and weekly from there to pine valley.