San Francisco–Oakland Bay Bridge facts for kids
Quick facts for kids San Francisco–Oakland Bay Bridge |
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The western span of the San Francisco-Oakland Bay Bridge
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| Coordinates | 37°49′5″N 122°20′48″W / 37.81806°N 122.34667°W |
| Carries | 10 lanes of  I-80 throughout, and pedestrians and bicycles east of Yerba Buena Island (YBI) |
| Crosses | San Francisco Bay via YBI |
| Locale | San Francisco and Oakland |
| Owner | Caltrans |
| Maintained by | Caltrans and the Bay Area Toll Authority |
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| Characteristics | |
| Design | Double-decked suspension spans (two, connected by center anchorage), tunnel, cast-in-place concrete transition span, self-anchored suspension span, precast segmental concrete viaduct |
| Material | Steel, concrete |
| Total length | West: 10,304 ft (3,141 m) East span: 10,176 ft (3,102 m) Total: 4.46 miles (7.18 km) excluding approaches |
| Width | West: 5 traffic lanes totaling 57.5 ft (17.5 m) East: 10 traffic lanes totaling 258.33 ft (78.74 m) |
| Height | West: 526 ft (160 m) |
| Longest span | West: two main spans 2,310 ft (704 m) East: one main span 1,400 ft (430 m) |
| Clearance above | Westbound: 14 feet (4.3 m), with additional clearance in some lanes Eastbound: 14.67 feet (4.47 m) |
| Clearance below | West: 220 feet (67 m) East: 191 feet (58 m) |
| History | |
| Designer | Charles H. Purcell |
| Construction begin | July 8, 1933 |
| Opened | November 12, 1936 |
| Statistics | |
| Daily traffic | 240,000 |
| Toll | Cars (east span, westbound only) $6.00 (rush hours) $2.50 (carpool rush hours) $4.00 (weekday non-rush hours) $5.00 (weekend all day) |
 San Francisco–Oakland Bay Bridge
Location in California
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The San Francisco-Oakland Bay Bridge is a very important bridge in California. It connects the cities of San Francisco and Oakland across the San Francisco Bay. This bridge is a key part of Interstate 80, a major highway.
The Bay Bridge is actually made of two main parts that cross the water. The western part is a suspension bridge. The eastern part is a self-anchored suspension bridge. This eastern part was rebuilt and opened in 2013. Before that, the old eastern part was a different type of bridge called a cantilever bridge. It was taken down after the new one was built.
The western part of the bridge has two levels, one above the other. Cars going west use the top level. Cars going east use the bottom level. The newer eastern part has all its lanes on one wide level. It is known for being one of the widest bridges in the world.
Contents
Building the Bay Bridge
The idea for a bridge across San Francisco Bay came up many years ago. People wanted an easier way to travel between San Francisco and Oakland. Before the bridge, people had to use ferries to cross the bay.
Early Plans and Design
Building such a large bridge was a huge challenge. Engineers had to figure out how to build it over deep water. They also had to consider the strong currents and the risk of earthquakes in the area. Many different designs were suggested over the years.
The final design for the original bridge was chosen in the early 1930s. Charles H. Purcell was the chief engineer for this massive project. Construction began in 1933.
How the Bridge Was Built
The bridge was built using a lot of steel and concrete. Workers had to build huge towers and supports in the water. They used special techniques to make sure the bridge would be strong.
The western part of the bridge has two suspension spans. These are connected in the middle by a large concrete block. This block is built on Yerba Buena Island. The eastern part of the original bridge was a cantilever design.
Opening Day
The San Francisco-Oakland Bay Bridge officially opened on November 12, 1936. This was a very exciting day for California. It made travel much faster and easier for everyone.
The Bridge and Earthquakes
California is known for earthquakes. The Bay Bridge was designed to be strong, but a major earthquake in 1989 caused some damage.
The 1989 Loma Prieta Earthquake
On October 17, 1989, a powerful earthquake hit the area. It was called the 1989 Loma Prieta Earthquake. This earthquake caused a section of the upper deck on the eastern part of the bridge to fall onto the lower deck.
The bridge was closed for about a month for repairs. This event showed that the eastern part of the bridge needed to be made even stronger.
Rebuilding the Eastern Span
After the earthquake, engineers decided that the eastern part of the bridge needed to be replaced. They wanted a new design that could handle future earthquakes better.
Work on the new eastern span began in 2002. It was a very complex project. The new span is a self-anchored suspension bridge. This means it has one main cable that loops around the bridge itself, rather than being anchored to the ground at both ends.
The new eastern span opened in September 2013. It is much wider and safer than the old one. It also has a path for bikes and pedestrians. The old eastern span was then carefully taken apart and removed.
Traveling on the Bridge
The Bay Bridge is very busy. About 240,000 vehicles cross it every day. It has 10 lanes for traffic.
Tolls
There is a toll to cross the bridge when you are driving west towards San Francisco. The cost of the toll changes depending on the time of day and the day of the week. For example, it costs more during busy rush hours.
Yerba Buena Island Tunnel
As you cross the bridge, you pass through a large tunnel on Yerba Buena Island. This tunnel is part of the bridge system. It helps connect the western and eastern spans.
Images for kids
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Sketch of the proposed "Rush San Francisco Trans-Bay Suspension Bridge" (1913)
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Preliminary layout studies for the bridge
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The Bay Bridge under construction at Yerba Buena Island in 1935
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A double balanced cantilever bridge, five truss bridges, and two truss causeways that connected Yerba Buena Island to Oakland. Dismantled in 2016.
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Traveling through the westbound upper level of the Yerba Buena tunnel
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The illuminated western span as seen from the Embarcadero in San Francisco
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Schematic drawing of the Bay Bridge
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Daytime view of the Bay Bridge and San Francisco seen from Yerba Buena Island
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A view of the Bay Bridge from the Bank of America building
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A view of Bay Bridge lights from a pier next to the Ferry Building in San Francisco
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A collapsed section of roadway deck after the 1989 earthquake
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Obsolete hot riveted laced ties (left, eastern span) and bolted box beam retrofit (right, western span)
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The eastern span in 2017
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A view of the San Francisco-Oakland Bay Bridge western span from the waterfront in San Francisco
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Some new construction (2004)
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Substantial progress (2011)
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The completed replacement and the old bridge (2013)
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Rest of old and new bridge (June 2015)
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Artist's simulation of final appearance after old span demolition
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See also
In Spanish: Puente de la Bahía de San Francisco a Oakland para niños
