The Chesapeake Bay Bridge is a dual-span bridge that spans the Chesapeake Bay and connects the eastern and western shores of Maryland in the United States. Officially named the William Preston Lane, Jr. Memorial Bridge after the governor of Maryland when construction began, it opened to the public as a two-lane highway in 1952. Its length of 4.32 miles (6.95 km) made it the longest over-water steel bridge at the time. A parallel span with three lanes was opened in 1973. Although all five lanes of the Chesapeake Bay Bridge technically are reversible, the newer span typically carries two westbound lanes and one reversible lane, with the original bridge carrying the eastbound lanes.
Before the Chesapeake Bay Bridge was built, trips between the Eastern Shore of Maryland and its Western Shore were lengthy and time-consuming. Ferries could not keep up with the demand. In 1938, the Maryland General Assembly authorized a bridge to be built between Kent Island and Annapolis, but World War II hampered the beginning of construction. Groundbreaking for the bridge finally occurred in 1949. Construction of the second span began in 1969.
The newer span was designed to be a modernized replica of the original bridge, but there are differences in their structures. Both spans feature a 1,600-foot (488-m) suspension bridge and a 690-foot (210-m) secondary bridge. The newer span, however, has taller suspension towers that have horizontal support beams, compared with the crisscrossing support beams of the older span's towers. The trusses on the new span are below the road as well, giving drivers and passengers a clear view of the bay. The newer span's secondary bridge is a steel arch structure, compared with the the cantilever design of the original span.
Commonly known as the Bay Bridge, the Chesapeake Bay Bridge connects the Baltimore and Washington, D.C., metropolitan areas to the more recreational Eastern Shore. It is heavily traveled in summertime and peak hours. The bridge is operated by the Maryland Transportation Authority, and a toll is charged for eastbound traffic. Cars are not permitted to pass other cars on the bridge.
Studies have been conducted to determine whether another bridge is needed either at the current site or farther north at Millers Island. These studies have estimated that traffic would increase, but a decision about another bridge had not been made by early 2011. The Chesapeake Bay Bridge's dual spans receive regular maintenance, including replacement of deck sections.