Lake Pontchartrain Causeway

Lake Pontchartrain Causeway
The southern end of the causeway at Metairie, Louisiana in 1998
Carries	4 lanes of Causeway Blvd
Crosses	Lake Pontchartrain
Locale	Metairie, Louisiana and Mandeville, Louisiana
Maintained by	Greater New Orleans Expressway Commission
Design	Low-level trestle with mid-span bascule
Total length	23.87 mi (38.442 km)
Vertical clearance	15 ft
Opened	August 30, 1956 (southbound) May 10, 1969 (northbound)
Toll	$3.00 (southbound)
Daily traffic	43,000[1]
Coordinates	30°11′59″N 90°07′22″W / 30.19972°N 90.12278°W / 30.19972; -90.12278Coordinates: 30°11′59″N 90°07′22″W / 30.19972°N 90.12278°W / 30.19972; -90.12278

The Lake Pontchartrain Causeway, sometimes only the Causeway,^[2] is a causeway composed of two parallel bridges crossing Lake Pontchartrain in southern Louisiana, United States. The longer of the two bridges is 23.83 miles (38.35 km) long. The southern terminus of the Causeway is in Metairie, Louisiana, a suburb of New Orleans. The northern terminus is at Mandeville, Louisiana.

Since 1969, it was listed by Guinness World Records as the longest bridge over water in the world; in 2011 in response to the opening of the allegedly longer Jiaozhou Bay Bridge in China, Guinness created two categories for bridges over water: continuous and aggregate lengths over water. Lake Pontchartrain Causeway then became the longest bridge over water (continuous)^[3] while Jiaozhou Bay Bridge the longest bridge over water (aggregate).^[4]

The bridges are supported by 9,500 concrete pilings.^[5] The two bridges feature bascule spans over the navigation channel 8 miles (13 km) south of the north shore.

History

The idea of a bridge spanning Lake Pontchartrain dates back to the early 19th Century and Bernard de Marigny, the founder of Mandeville. He started a ferry service that continued to operate into the mid 1930s. In the 1920s, a proposal called for the creation of artificial islands that would then be linked by a series of bridges. The financing for this plan would come from selling homesites on the islands. The modern Causeway started to take form in 1948 when Ernest M. Loeb Jr. envisioned the project. Due to his lobbying and vision, the Louisiana Legislature created what is now the Causeway Commission. The Louisiana Bridge Company was formed to construct the bridge, who in turn appointed James E. Walters Sr. to direct the project.^[6]

Satellite view

The original Causeway was a two-lane span, measuring 23.86 miles (38.40 km) in length. It opened in 1956 at a cost of $30.7 million. A parallel two-lane span, 1/100th of a mile (15 m) longer than the original, opened on May 10, 1969, at a cost of $26 million.

Since its construction, the Causeway has operated as a toll bridge. Until 1999, tolls were collected from traffic going in each direction. To alleviate congestion on the south shore, toll collections were eliminated on the northbound span. The standard tolls for cars changed from $1.50 in each direction to a $3 toll collected on the North Shore for southbound traffic only.

The opening of the Causeway boosted the fortunes of small North Shore communities by reducing drive time into New Orleans by up to 50 minutes, bringing the North Shore into the New Orleans metropolitan area. Prior to the Causeway, residents of St. Tammany Parish used either the Maestri Bridge on U.S. Route 11 or the Rigolets Bridge on U.S. Route 90, both near Slidell, Louisiana or on the west side via U.S. Route 51 through Manchac, Louisiana.^[7]

After Hurricane Katrina on August 29, 2005, videos collected showed damage to the bridge. The storm surge was not as high under the Causeway as it was near the I-10 Twin Span Bridge and damage was mostly isolated on the turnarounds.^[8] A total of 17 spans were lost.^[8] Structural foundations remained intact. The causeways have never sustained major damage of any sort from hurricanes or other natural occurrences, a rarity among causeways. The existing fiber optic cable plant was blown out of its tray but remained intact per optical time domain reflectometer (OTDR) analysis. With the I-10 Twin Span Bridge severely damaged, the Causeway was used as a major route for recovery teams staying in highlands to the North to get into New Orleans. The Causeway reopened first to emergency traffic and then to the general public - with tolls suspended - on September 19, 2005. Tolls were reinstated by mid-October of that year.

Lake Pontchatrain Causeway Southbound

The Lake Pontchartrain Causeway is one of seven highway spans in Louisiana with a total length of 5 miles (8.0 km) or more. The others are, in order from longest to shortest, the Manchac Swamp bridge on I-55, the Atchafalaya Basin Bridge on I-10, the Bonnet Carré Spillway bridge on I-10, the Chacahoula Swamp Bridge on U.S. 90, the Lake Pontchartrain Twin Spans on I-10, and the LaBranche Wetlands Bridge on I-310. The Maestri Bridge comes close, but runs short two tenths of a mile at roughly 4.8 miles (7.7 km) in total length. In a few years the Leeville-Port Fourchon Bridge on Louisiana Highway 1 at over 17 miles (27 km) in total length will join this list. Louisiana is also home to the Norfolk Southern Lake Pontchartrain Bridge, which at 5.8 miles (9.3 km) is one of the longest railway bridges in the United States.

The southern end of the Manchac Swamp bridge (on the western edge of Lake Pontchartrain) is the western end of the Bonnet Carré Spillway bridge (on the southwestern edge of Lake Pontchartrain) and the northern end of the LaBranche Wetlands (Destrehan Swamp) bridge is the eastern end of the Bonnet Carré Spillway bridge, so these three bridges by name are in fact one contiguous bridge. The total driving distance on continuous elevated roadway is over 38 miles (61 km).

Longest bridge controversy July 2011

For decades Lake Pontchartrain Causeway was listed by Guinness World Records as the longest bridge over water in the world. In July 2011 the Jiaozhou Bay Bridge in China was named by Guinness as the 'longest bridge over water'.^[4] At that time there was some controversy in the USA as the former holder of the record, the Lake Pontchartrain Causeway, disagreed with Guinness and still called itself the longest.^[9] It made this claim by ruling on the title according to its own definition — that is, how much of a bridge is physically over water, saying that the Jiaozhou Bay Bridge spans water for 25.9 kilometres (16.1 mi) while Lake Pontchartrain Causeway spans 38.28 kilometres (23.79 mi).^[9] Shandon Hi-Speed group, the company that built the Jiaozhou Bay Bridge, says its sea crossing length is actually 25.171 kilometres (15.641 mi).^[10] Nevertheless, Guinness World Records stated that the Jiaozhou Bay Bridge is 42.5 kilometres (26.4 mi) long^[4] by including other aggregate structures such as land bridges on the ends, and an under-sea tunnel in another part of the city that was part of the same Jiaozhou Bay Connection Project.^{[citation needed]}

In July 2011, Guinness created two categories for bridges over water: continuous and aggregate lengths over water. Lake Pontchartrain Causeway then became the longest bridge over water (continuous)^[3] while Jiaozhou Bay Bridge became the longest bridge over water (aggregate).^[4]

See also

Wikimedia Commons has media related to Lake Pontchartrain Causeway.

• List of bridges in the United States
• List of longest bridges in the world
• Megaproject
• Prestressed concrete

References

External links

• The Causeway website
• Google Maps satellite image

v t e Bridge-related articles Types Moveable bridge Beam bridge Box girder bridge Burr truss Cantilever bridge Arch bridge Suspension bridge Timber bridge Cable-stayed bridge Truss bridge Visual index to various types Lists List of bridges By length Suspension bridges Cable-stayed bridges Cantilever bridges Continuous truss bridges Arch bridges Masonry arch bridges Highest Tallest Bridge failures Bridge to nowhere Category     Commons    WikiProject     Portal