WHAT IS A BRIDGE A bridge is a structure that crosses over something Bridges allow people to go over obstacles This makes travel faster and safer Many bridges cross bodies of water such as rivers Bridges also connect islands to mainlands Other bridges are built over obstacles on land For example many highways have bridges that let roads cross over each other These are called overpasses 4 BRIDGE OVER WATER HIGHWAY OVERPASS
PARTS OF A BRIDGE There are many kinds of bridges They all look a little different But there are a few basic parts that are similar in all bridges The surface of a bridge is called the bridge deck The bridge deck has at least two supports The part of a support that is above ground is a pier The part that is below ground is a pile A place where an end of the bridge deck meets a support is called an abutment The section of bridge deck between two piers is called a span A bridge can have one or many spans BRIDGE DECK ABUTMENT SPAN PIER PILE PILE
HOW PEOPLE USE BRIDGES Bridges are built for different kinds of traffic These include bicycles and pedestrians trains and cars Some bridges have sections for two or more types of traffic FOOT TRAFFIC People walk across the Millennium Bridge in London England 6
THE GOLDEN GATE BRIDGE The Golden Gate Bridge is in California It connects the city of San Francisco and Marin County The bridge opened in 1937 It is one of the most famous bridges in the world It has six lanes for car traffic It also has pathways for pedestrians and bicycles Every day more than 100,000 people cross the Golden Gate Bridge CAR TRAVEL Cars drive across the San Francisco Oakland Bay Bridge in California TRAIN CONNECTIONS A train crosses the New River in West Virginia 7
