By the mid 1930s, following 4 decades as an incorporated town and 4 previous decades of settlement before that, Emeryville had matured as a community. During the middle decades of the 20^th Century, from the 1930s to the 1960s, with a population hovering around 2,500, the town continued to grow and flourish as an industrial and transportation hub at the very center of the Bay Area.

World War II
Following the bombing of Pearl Harbor in December 1941, the United States entered World War II. Federal money poured into the Bay Area’s shipbuilding and defense industries, and Emeryville geared up for war. Factories operated 24-hours a day with 3 shifts and workers came from all over the country. The town’s 185 industrial firms employed almost 30,000 workers, including many women and African-Americans, to fulfill government contracts. Existing industries, such as Pabco Paints and Westinghouse, expanded their operations, and new facilities were established, such as the Grove Regulator Company and Ryerson Steel Mill, both at 65^th and Hollis Streets in old Butchertown.

The Key System created a special Shipyard Railway line, which operated from 1943 to 1945, to carry workers from the transit hub at San Pablo and Yerba Buena Avenues to the shipyards in Richmond.

Bay Bridge
Just prior to the war, construction of the San Francisco-Oakland Bay Bridge in 1936 brought big changes to Emeryville and the East Bay. The double-deck bridge featured 6 lanes of 2-way auto traffic on the upper deck, and railroad tracks and a roadway for trucks on the lower deck. Three new highways connected the bridge to the roads of the East Bay: to the south, a viaduct connected to Cypress Street and State Highway 17 in West Oakland; to the east, an underpass was built below San Pablo Avenue at the south end of Emeryville connecting to U.S. 50 via 38^th Street (later rebuilt as West MacArthur Boulevard); and to the north, the new Eastshore Highway was built in the Bay, about a quarter mile west of the previous shoreline, through Emeryville, Berkeley, and Albany, connecting to San Pablo Avenue in El Cerrito.

These roads diverged east of the bridge in a massive tangle of ramps and overpasses just south of the Emeryville border officially called the “Distribution Structure,” but more commonly known as the “Maze.” After MacArthur Boulevard was built to carry U.S. 50 across Oakland, it became known as the MacArthur Maze. Today it is 1 of the busiest freeway interchanges in the United States.

Highways
When the U.S. highway system was established in 1926, U.S. 40 ran from San Francisco to Atlantic City, New Jersey via Baltimore, crossing the bay on a ferry and then running via 7^th Street and Broadway in Oakland to San Pablo Avenue through Emeryville and on across the state via Sacramento. After the Bay Bridge was opened, U.S. 40 was relocated to follow the bridge and the new Eastshore Highway. This major arterial had at-grade intersections at Powell Street and Ashby Avenue, and, for the 1st time, provided fast, direct motor vehicle access to the industries in the “bay front” area of Emeryville west of the railroad tracks.

Ashby Avenue, at Emeryville’s northern border, was State Highway 24 and provided a connection to Walnut Creek via the new Caldecott Tunnel. MacArthur Boulevard, at the city’s southern edge, was U.S. 50, which headed east to Stockton and on across the country to Ocean City, Maryland via St. Louis and Washington, DC. In the early 1950s, following World War II, the Eastshore Highway was converted into a freeway with grade-separated interchanges at Powell Street and Ashby Avenue, and the MacArthur Freeway was built to carry U.S. 50 past Emeryville though Oakland, paralleling MacArthur Boulevard.

After the Interstate Highway System was created in 1956, U.S. 40 became Interstate 80, which closely followed the route of the Lincoln Highway, the 1st road across the country, from San Francisco to New York. The MacArthur Freeway was redesignated from U.S. 50 to Interstate 580, running east through Alameda County to connect San Francisco to Interstate 5 in the Central Valley, and becoming the most direct route to Los Angeles. Emeryville was at the confluence of all of these major cross-country highways which made it an ideal location for industry.

In 1958, an ambitious Highway Master Plan, created for Alameda County by Wilbur Smith and Associates, called for a new “Shoreline Freeway” running parallel to the Eastshore Freeway, about a half mile out in the bay. It was to extend from Albany in the north to the Dumbarton Bridge in the south, through Emeryville. The plan also called for Ashby Avenue to be turned into a freeway connecting the Shoreline and Eastshore Freeways with the Caldecott Tunnel. Needless to say, neither of these proposed freeways was ever built.

Public Transportation
Public Transportation also benefited from the Bay Bridge, although the days of the interurban electric train were numbered. Rail service on the bridge did not begin until 1939, and both the Key System and the East Bay Electric Lines (which changed its name to Interurban Electric Railway or simply IER) ran across it. For the 1st time, passengers could ride directly from the East Bay to the new Transbay Terminal in downtown San Francisco without having to switch to a ferry boat at the Oakland waterfront, although automobiles were able to drive across the bridge to San Francisco 3 years earlier, which put public transportation at a distinct disadvantage.

The IER trains ran from the bridge to the Southern Pacific mainline tracks, and then along the Berkeley Branch up Stanford Avenue, with 1 line heading north through Emeryville to Albany, and another heading northeast along Stanford to downtown Berkeley. These routes connected on Solano Avenue in North Berkeley to form a loop. The IER lasted less than 2 years following the opening of the bridge. Competition from automobile traffic proved insurmountable, and the last IER train to Berkeley ran in 1941.

Key System
The Key System was more successful. Its trains headed east from the Bay Bridge and crossed under the Southern Pacific tracks via a subway (which today is used by the East Bay Municipal Utility District to access their sewage treatment plant) and followed the old California and Nevada right-of-way along Yerba Buena Avenue. Two lines branched off to the south through West Oakland and traveled on to downtown Oakland and the Lakeshore district; the other lines continued east to the major transit hub at San Pablo Avenue. From there, they branched out to serve various parts of North Oakland and Berkeley.

But gradually the Key System began converting both its interurban trains and its local streetcars to buses, beginning as early as the 1930s. In 1946, the Key System was sold to the bus conglomerate National City Lines, which accelerated the conversion to buses. In 1955, the Key System asked the California Public Utilities Commission for permission to abandon all transbay lines and substitute buses. The last Key System train ran across the Bay Bridge on April 20, 1958, less than 20 years after the inauguration of transbay service. In 1960, the Key System’s bus operations were taken over by a newly formed public agency, the Alameda-Contra Costa Transit District (AC Transit), which today runs an extensive system of both local and transbay buses throughout Emeryville and the East Bay.

In 1963, the rails were removed from the Bay Bridge and it was converted to its current configuration for motor vehicles only, with 5 westbound lanes on the upper deck, and 5 eastbound lanes on the lower deck.

The 1950s
After World War II, the nation experienced unprecedented prosperity in the 1950s, as freeways were built, sprawling residential suburbs were created in outlying areas, and more and more people took to the automobile as their sole means of transportation. Emeryville, with its solid industrial base and well-established transportation infrastructure of railroads and freeways, continued to flourish during this era until the 1960s, when industries began to abandon their central city locations and the city fathers made ambitions plans for transforming the city.