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Paper Highways; Unbuilt California State Route 93

In this edition of Paper Highways we look at the history of the unbuilt California State Route 93 in the San Francisco Bay Area.



The History of California State Route 93

The history of CA 93 dates back to Legislative Routes (LRNs) that were added to the Freeway & Expressway System during 1959.  Specifically the LRNs that would make up the future planned route of CA 93 were as follows:

LRN 255 west from LRN 107 in Alamo to LRN 235 near Burton.
LRN 235 west from LRN 255 near Burton to LRN 254 near Moraga.  Note; LRN 235 was added to the State Highway System in 1953 as LRN 233 between CA 17/LRN 69 and US 50/LRN 50.  LRN 233 was reassigned as LRN 235 in 1957 and extended to Concord.
LRN 254 from LRN 235 northwest along the San Pablo Reservoir to I-80/US 40/LRN 7.
-  LRN 254 from I-80/US 40/LRN 7 west to CA 17/LRN 69.

The future planned route of CA 93 appears as LRN 255, LRN 245, and LRN 254 on the 1960 Division of Highways State  Map.


During the 1964 State Highway Renumbering LRN 255 and LRN 254 were assigned as CA 93.  CA 93's planned route would have included a multiplex of what was LRN 235 on what was renumbered to planned CA 77.   CA 93 was defined as; Route 680 near Alamo to Route 77 near Burton, Route 77 to Route 24 near Orinda, Route 24 near Orinda to Route 17 in Richmond via San Pablo.  Planned CA 93 was meant to be a freeway grade entirely contained within Contra Costa County and would have traversed a relatively sparsely populated part of the Diablo Range between Alamo westward to San Pablo.  The new planned route of CA 93 can be seen on the 1964 Division of Highways State Map.



According to CAhighways the definition of planned CA 93 was truncated to planned CA 77 near Burton during 1973.  The shortened planned route of CA 93 can be seen on the 1975 Caltrans State Map City Insert.


CA 93 has never had an officially adopted alignment but has a defined traversable route:

1.  From planned CA 77 Moraga Way west to CA 24.
2.  From CA 24 in Orinda; Camino Pablo and San Pablo Dam Road  west to I-80.
3.  From I-80 Richmond Parkway west to I-580.

Note; Richmond Parkway is an expressway grade built by the City of Richmond over the corridor of CA 93 between I-80 and I-580.  The City of Richmond apparently does want Richmond Parkway added to the State Highway System as CA 93 and has signed it with Contra Costa County Route 93 on 511 Signs.  According to CAhighways.org Richmond Parkway won't be accepted by the State until it is brought up to Caltrans Expressway standards.   The planned route of CA 93 can be seen on the 2005 Caltrans Map essentially unaltered from 1973 (note; the definition of CA 93 was clarified in 1988).


From I-80 westbound the route of Richmond Parkway is signed on guide signs as "To I-580."


I-80 westbound Exit 20 doesn't even contain a reference Richmond Parkway but is again signed as "To I-580."  If CA 93 were to be constructed to plan I-80 west Exit 20 would be the approximately junction of where it would cross I-80.




As noted above Contra Costa County Route 93 can be seen on the 511 signs of Richmond Parkway.  Oddly the 511 signs on Richmond Parkway state "Freeway Assist."  Richmond Parkway presently is 7 miles in length and was constructed during the 1990s.  Note; this image was snipped from Google Maps.


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