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California State Route 242

After driving the Warren Freeway on California State Route 13 east via CA 24 and Interstate 680 to drive California State Route 242.


CA 242 is a 3 mile freeway in Contra Costa County which runs northward from I-680 in Pleasant Hill to CA 4 in Concord .  CA 242 is a former segment of what was once a much larger CA 24 which was routed through the area on Legislative Route Number 75 in 1935 when it was extended to Berkeley from Sacramento.

The route of CA 24 from originally used the following alignment prior to the present CA 242 freeway being completed:

-  CA 24 was multiplexed with CA 21 north from Walnut Creek to Pleasant Hill.  CA 24/CA 21 entered Pleasant Hill on Contra Consta Boulevard where CA 24 split on Monument Road towards Concord.
-  CA 24 entered Concord on Monument Road which becomes Galindo Street entering downtown.
-  CA 24 exited downtown via Willow Pass Road which continued to CA 4.

The original alignment of CA 24 on the current CA 242 corridor can be seen on the 1938 State Highway Map.

1938 State Highway Map

By 1946 a new proposed alignment of CA 24 bypassing downtown Concord along what essentially is the modern CA 242 corridor is shown on the State Highway Map.

1946 State Highway Map

CA 24 was realigned by 1948 on a partially constructed Concord Bypass.  CA 24 was routed out of downtown Concord via Concord Avenue to the new limited access grade which is now the northern extent of CA 242.

1948 State Highway Map

In 1959 a new proposed cut-off route for CA 24 which would take a wide bypass of Concord to Antioch was assigned as LRN 256 according to CAhighways.org.

CAhighways.org on LRN 256

LRN 256 can be seen on the 1960 State Highway Map.

1960 State Highway Map

During the 1964 State Highway renumbering the planned path of LRN 256 was assigned to LRN 24.  CA 24 from Pleasant Hill to Concord stayed signed as CA 24 but was assigned LRN 242.

1963 State Highway Map

1964 State Highway Map

By 1965 the Concord bypass was completed and what is essentially modern CA 242 took form.

1965 State Highway Map

Interestingly CA 24 signage on the Concord bypass isn't changed on State Highway maps until 1988.  CA 24 appears to have been cut back to Walnut Creek at I-680 by 1988. 

1986 State Highway Map 

1988 State Highway Map

According to CAhighways.org the entire route of CA 242 appears to have been fully converted to freeway standards by 1992.  The planned route of CA 24 via what was LRN 256 appears to have never been officially cancelled.

CAhighways.org on CA 24

My approach to CA 242 was via CA 24 east and I-680 north.  The photo below is the eastern terminus of CA 24 at I-680 in Walnut Creek.  As described above it was wasn't until the late 1980s when the I-680/CA 24 multiplex was elminated.


I-680 north meets CA 242 at Exit 50 at a split junction.  I-680 essentially follows the former path of CA 21 whereas CA 242 obviously is the former path of CA 24.




As CA 242 north begins it almost immediately enters Concord.


CA 242 north has exits for; Clayton Road, Concord Avenue, Grant Street and Olivera Road before the terminus at CA 4.  The north terminus of CA 242 includes ramps to both CA 4 west and CA east.








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