Current California State Route 13 ("CA 13") was designated in 1964 on what was Legislative Route Number 258 ("LRN 258") between CA 61 to Interstate 580 ("I-580"), LRN 227 from I-580 to CA 24 and CA 24/LRN 206 to CA 61. The change in designations during the 1964 State Highway Renumbering can be observed by comparing the State Highway Map City Insert to the 1963 edition.
1963 Division of Highways Map City Insert
LRN 227 was designated by 1947 Legislative Chapter 11 between CA 24/LRN 75 and US 50/LRN 5 in 1947 according to CAhighways.org. LRN 227 can be seen on the 1948 Division of Highways Map City Insert. The implied route of LRN 227 is shown to largely follow Mountain Boulevard between CA 24 southeast to US 50.
The Warren Boulevard Freeway is displayed in March/April 1966 California Highways & Public Works article regarding the MacArthur Freeway (I-580). The MacArthur Freeway/Warren Boulevard Freeway interchange is cited as being completed in November 1965.
1969 Division of Highways State Map City Insert
I-580 east doesn't have a direct connection to CA 13/Warren Freeway. CA 13 traffic is directed onto Exit 26 where it must enter the Warren Freeway via Calaveras Avenue and Mountain Boulevard.
The Warren Freeway segment of CA 13 is only 5 miles in length north to CA 24. Interestingly the ridge utilized by the Warren Freeway apparently is directly on top of the Hayward Fault which devastated Alameda County in 1868.
CA 13 follows Ashby Avenue westward through Berkeley. CA 13 has a major intersection CA 123/San Pablo Avenue (former US 40) located at Postmile ALA 13.17.
CA 13 follows Ashby Avenue westward to a terminus at I-80/I-580.
- Published; 2/21/19
- Update 1; 1/31/21