San Diego–Coronado Bridge

San Diego-Coronado Bay Bridge
Coordinates	32°41′11″N 117°09′30″W
Carries	SR 75
Crosses	San Diego Bay
Locale	San Diego and Coronado, California
Characteristics
Design	Prestressed concrete/steel bridge
Total length	3.4 kilometres (2.1 mi)
Longest span	1,880 feet (573 m)
Clearance below	60.96 meters (200 ft)
History
Opened	1969
Location

The San Diego-Coronado Bay Bridge, locally referred to as the Coronado Bridge, is a "prestressed concrete/steel" girder bridge, crossing over San Diego Bay in the United States, linking San Diego with Coronado, California. The bridge is signed as part of State Route 75.

Description

The 11,179-foot-long (3,407 m or 2.1 mi) bridge ascends from Coronado at a 4.67 percent grade before curving 80 degrees toward San Diego. The span reaches a maximum height of 200 feet (61m), allowing the U.S. Navy ships which operate out of the nearby Naval Station San Diego to pass underneath it. The five-lane bridge featured the longest box girder in the world until it was surpassed by a bridge in Chongqing, China in 2008. The bridge doesn't form a direct path to Coronado, but rather has a curve. This was done so it would be high enough for all U.S. Navy ships to pass underneath but not too steep for vehicles to ascend and descend.

The San Diego-Coronado Bay Bridge construction started in February 1967, and the bridge was opened to traffic on August 3, 1969, during the celebration of the 200th anniversary of the founding of San Diego. Originally, the toll was $0.60 in each direction. Several years later, this was changed to a $1 toll collected for traffic going westbound to Coronado only. Although the bridge was supposed to become "toll-free" once the original bridge bond was paid (which occurred in 1986), the tolls continued for sixteen additional years. In 2002, it became the last toll bridge in Southern California to discontinue tolls. The original toll booths remained intact for a short while, and were temporarily replaced with newer, more modern-looking toll booths for the filming of a car commercial in April 2007. The islands upon which the toll booths sat, as well as the canopy over the toll plaza area, are still intact, located at the western end of the bridge in the westbound lanes. Though tolls are no longer collected, beginning February 19, 2009 there was talk of resuming westbound toll collection.

The eastern end of the bridge connects directly to a T interchange with Interstate 5, just southeast of downtown San Diego. It is designated and signed as part of California State Highway 75. The bridge was designed entirely and exclusively for motor vehicle traffic; there are no pedestrian walkways, bike paths, or shoulders ("breakdown lanes"). Beginning in 2008, cyclists have the once-a-year opportunity to ride over the bridge in the Bike the Bay "fun ride".

It is the third deadliest suicide bridge in the USA, trailing only the Golden Gate Bridge in San Francisco and the Aurora Bridge in Seattle. Between 1972 and 2000, more than 200 suicides occurred on the bridge. Signs have been placed on the bridge urging potential suicides to call a hotline.

General facts

A view of the bridge from a commercial jet

A daytime panorama of the bridge in 2010

• Principal architect: Robert Mosher
• Opened on August 3, 1969
• in 1970, it won the Most Beautiful Bridge Award from American Institute of Steel Construction
• 3.4 kilometres (2.1 mi) long
• cost $50 million to build
• retrofitting cost $70–150 million
• 20,000 tons of steel (13,000 tons in structural steel and 7,000 in reinforcing steel)
• 94,000 cubic yards of concrete
• 900,000 cubic yards of dredged fill
• some caissons for the towers were drilled and blasted 100 feet into the bed of the San Diego Bay
• 4.67% grade from Coronado to San Diego
• side railings are concrete blocks only 34 inches high
• over 50 people worked 24 hours a day, seven days a week to maintain the bridge and take its tolls—tolls have since been discontinued
• the grade, 200 foot clearance at peak, and the 90-degree angle turn is to create clearance for an empty oil-fired aircraft carrier to pass beneath it - it is not sufficient for Nimitz-class nuclear aircraft carriers
• the bridge is the third largest orthogonal box in the country - the box is the center part of the bridge, between piers 18-21 over main shipping channel

External links

• Caltrans - Bridge History and Facts
• Caltrans - Bridge Contracts
• California Department of Transportation -The San Diego-Coronado Bridge
• City of Coronado - Transportation Management Association Bridge