Editing Dumbarton Bridge (California) (section)

==Roadway connections==
{{More citations needed section|date=November 2021}}

The bridge is part of [[California State Route 84|State Route 84]], and is directly connected to [[Interstate 880 (California)|Interstate 880]] by a [[freeway]] segment north of the Fremont end.
There is no freeway connection between [[U.S. Route 101 in California|U.S. 101]] and the southwest end of the Dumbarton Bridge. Motorists must traverse one of three at-grade routes to connect from the Bayshore Freeway to the bridge. These are (from northwest to southeast):
# the Bayfront Expressway, a [[limited-access road]] linking to U.S. 101 at Marsh Road, [[Atherton, California|Atherton]] (the official routing of SR 84)
# Willow Road ([[California State Route 114|SR 114]]), an approximately one-mile expressway through east Menlo Park to U.S. 101
# University Avenue ([[California State Route 109|SR 109]]), an [[arterial road]] and the main commercial street of [[East Palo Alto, California|East Palo Alto]].

The Willow Road and University Avenue junctions with Bayfront Expressway are at-grade intersections controlled by traffic lights; there are two additional controlled intersections at Chilco Road and Marsh Road, and the Marsh Road interchange on U.S. 101 is a [[Partial cloverleaf interchange|parclo]]. The result is that Bayfront Expressway is frequently congested, and when not congested is often the site of high-speed car crashes. In 2007, author [[David Halberstam]] was killed in one such crash at the Willow Road intersection.

Access to [[Interstate 280 in California|I-280]] is available via State Route 84 to Woodside Road (as signed) or other arterial routes. There are no cross-Peninsula freeway connections between State Routes 92 and 84. In addition, there are no direct cross-Peninsula arterial routes between State Route 84 and Page Mill Road, a five-mile gap.

Although the present situation has resulted in severe traffic problems on the bridge itself and in Menlo Park and East Palo Alto, Caltrans has been unable to upgrade the relevant portion of Highway 84 to freeway standards for several decades, due to opposition from the cities of Menlo Park, Atherton and [[Palo Alto, California|Palo Alto]]. Freeway opponents fear that upgrading Highway 84 will encourage more people to live in southern [[Alameda County, California|Alameda County]] (where housing is more affordable) and commute to jobs in the mid-Peninsula area (where businesses wish to be located in order to be close to [[Silicon Valley]]), thus increasing traffic in their neighborhoods to the south and west of U.S. 101 and even along State Routes 85 and 237.

Bus service across the bridge is provided by the [[Dumbarton Express]], run by a consortium of local transit agencies ([[SamTrans]], [[AC Transit]], [[Santa Clara Valley Transportation Authority|VTA]] and others) which connects to [[Bay Area Rapid Transit|BART]] at Union City and [[Caltrain]] at Palo Alto and California Avenue. AC Transit also runs Transbay buses U ([[Fremont (BART station)|Fremont BART]] and [[Fremont-Centerville (Amtrak station)|Amtrak]] to [[Stanford University|Stanford]]) and DA (Ardenwood to [[Oracle Corporation|Oracle]] and [[Facebook]] headquarters) across the bridge. The free [[Stanford Marguerite Shuttle]] also runs buses AE-F and EB across the bridge.