| 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 | 23.83 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] |
The Lake Pontchartrain Causeway, or the Causeway, consists 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. 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 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)[2] while Jiaozhou Bay Bridge the longest bridge over water (aggregate).[3]
The bridges are supported by 9,500 concrete pilings.[4] The two bridges feature bascule spans over the navigation channel 8 miles (13 km) south of the north shore. The southern terminus of the Causeway is in Metairie, Louisiana, a suburb of New Orleans. The northern terminus is at Mandeville, Louisiana.
Contents |
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.
The original Causeway was a two-lane span, measuring 23.86 miles (38.40 km) in length, that 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. The Causeway has always been 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 $3.00 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.
After Hurricane Katrina on August 29, 2005, videos collected showed damage to the bridge, but the damage was mostly on the unused turnaround on the older southbound span; the structural foundations remained intact. The Causeways have never sustained major damage of any sort due to hurricanes and other natural occurrences, a rarity in the causeway community. The existing fiber optic cable plant was blown out of the 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. Tolls were reinstated by mid-October.
The Lake Pontchartrain Causeway is one of seven highway spans in Louisiana that have 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).
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'.[3] 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.[5] 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 the Jiaozhou Bay Bridge is over water for 25.5 kilometres (15.8 mi) while Lake Pontchartrain Causeway crosses water for 38.28 kilometres (23.79 mi).[5] However, the quoted number of 25.5 kilometres (15.8 mi) was made by a representative of Lake Pontchartrain Causeway[5] and the methodology they used for arriving at this number was unstated;[5] for example, Jiaozhou Bay Bridge is a complex structure with some entry/exit ramps extending independently (as separate bridges) for long distances over open water, and curves in the bridge adding additional distances — it was unstated if these were accounted for or not in the 25.5 km figure.[5] Guinness World Records states that the Jiaozhou Bay Bridge is 42.5 kilometres (26.4 mi) long.[3]
In July 2011, in response to the controversy, 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)[2] while Jiaozhou Bay Bridge became the longest bridge over water (aggregate).[3]
|
||||||||
|
||||||||||
|
|||||||||||