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California State Route 84 west from Interstate 880 over the Dumbarton Bridge

On a recent Bay Area trip I took California State 84 west from Interstate 880 over San Francisco Bay via the Dumbarton Bridge.


The Dumbarton Bridge is a 1.63 mile structure crossing San Francisco Bay near Dumbarton Point.  The Dumbarton Bridge is the southernmost bridge in San Francisco Bay and the shortest.  The current Dumbarton Bridge was completed by 1982 in a four-lane configuration and was expanded to six-lanes by 1989.

The original Dumbarton Bridge opened in 1927 and was built private money.  The 1927 Dumbarton Bridge was similar to the 1929 San Mateo-Hayward Bridge in that it featured a causeway structure and a center vertical lift span.  Like the 1929 San Mateo-Hayward Bridge the 1927 Dumbarton Bridge was purchased by the California Division of Highways in 1951.  The 1927 Dumbarton Bridge became part of Legislative Route 107 which already existed on both ends of the structure since 1933.  Said change to LRN 107 can be observed by comparing the 1951 State Highway Map to the 1952 edition.

1951 State Highway Map

1952 State Highway Map

LRN 107 and the 1927 Dumbarton Bridge would become part of CA 84 during the California Highway Renumbering of 1964.

1963 State Highway Map

1964 State Highway Map

The 1927 Dumbarton Bridge was mostly demolished in 1984 but a small portion of the eastern approach near in Newark exists as a fishing pier.

My approach to CA 84 west and the Dumbarton Bridge were from I-880 south.





CA 84 west enters the City Limits of Newark (Alameda County) west of I-880.  CA 84 west to the Dumbarton Bridge toll is a freeway grade signed at 65 MPH.


Heading west on CA 84 it is apparent some of the overhead signage has seen better days.


Tolls for the Dumbarton Bridge are collected on westbound CA 84 and are $6 dollars cash for a two axle vehicle.  The last Exit before the Dumbarton Bridge toll is at Thorton Avenue/Paseo Padre Parkway.








West of the Dumbarton Bridge toll the route of CA 84 largely falls below freeway standards and has a poor surface quality.  The speed limit over the Dumbarton Bridge is 55 MPH.









As the Dumbarton Bridge rises over San Francisco Bay it enters San Mateo County and Menlo Park.


The Dumbarton Bridge ends in Menlo Park.  CA 84 continues west over the San Cruz Mountains to CA 1 on the Pacific Ocean.  After crossing the Dumbarton Bridge I turned south on CA 109 on University Avenue.










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