Lake Pontchartrain Causeway, Louisiana


Lake Pontchartrain Causeway
Spans Lake Pontchartrain
Lanes 2×2
Total length 38,442 meters
Main span ?
Bridge deck height 5 meters
Opening 30-08-1956
Traffic intensity 43,000 mvt/day
Location Map

According to allcitycodes, the Lake Pontchartrain Causeway is a 38.4 kilometer long bridge in the United States, located in the state of Louisiana, near the city of New Orleans. It has been the longest bridge over water in the world since 1956.


The bridge crosses the middle of Lake Pontchartrain.

The Lake Pontchartrain Causeway consists of two parallel girder bridges with a length of 38.4 kilometers each. The bridge is a low bridge with a clear passage of only 5 meters, but there is a bascule bridge 13 kilometers south of the north bank. The bridge consists of 9,500 bridge piers. The bridge spans the widest part of Lake Pontchartrain between New Orleans to the south and Mandeville to the north. The bridge itself has 2×2 lanes and is actually a freeway, although it does not connect directly to other highways. The bridge can be completed in 22 minutes at a maximum speed of 65 mph (105 km/h).

Although it is called a causeway, it is actually an overpass. A causeway is a slope in water on which a road lies, whether or not connected with bridges. However, the Lake Pontchartrain Causeway is a full length viaduct with piers in the water. The Lake Pontchartrain Causeway is not a state highway and has no road number.


The bridge seen from one of the seven crossovers.


Already in the early 1800s there were plans for a fixed connection over the Lake Pontchartrain. A ferry service was established as a temporary solution.

In the early 20th century, New Orleans wasonly accessible to the west, via roads along the Mississippi River. Traffic to the north or east had to go all the way around the Lake Pontchartrain. In the 1920s there were plans for the New Orleans–Hammond Lakeshore Highway, a scenic highway along the south and west shores of Lake Pontchartrain. Due to the problems with the swamps, this plan was ultimately not completed. Only the northern part of this section has been constructed along the west side of Lake Pontchartrain between Laplace and Hammond. This section was built on a slope by the Manchac Swamp and opened to traffic on April 1, 1927. The portion in what is now the New Orleans metropolitan area was completed in the early 1930s as State Highway 33 between New Orleans and Kenner. The part through the swamps in St.

The construction of the Bonnet Carré Spillway in 1933 killed the project of a road along the shore of Lake Pontchartrain. The Bonnet Carré Spillway is an overflow from the Mississippi River to Lake Pontchartrain at high tide. This was to prevent flooding in New Orleans. To this end, the water would have to flow unimpeded to Lake Pontchartrain, and an embankment at the location of the Lakeshore Highway would not fit. The project was then scrapped.

In the late 1920s, New Orleans was opened up to the east with the construction of the Maestri Bridge of US 11 in 1928 and the Chef Menteur Bridge of US 90 in 1929. These bridges provided good access to New Orleans in all directions except straight to the north, where one still had to go west or east around Lake Pontchartrain.

Construction of the first span

The bascule bridge.

As early as 1924, a law was passed allowing the construction of a toll bridge over Lake Pontchartrain. In December 1924, the Lake Pontchartrain Causeway Association was formed. In the first plans, a chain of 18 islands was proposed. The plan for a toll road was unpopular, however, and toll-free roads to and from New Orleans were built in the 1920s and 1930s. Plans for a bridge across Lake Pontchartrain were subsequently shelved.

In 1948, the issuance of $40 million in bonds for the construction of a bridge link across Lake Pontchartrain was approved by the voter. Actual planning by governments on both sides of Lake Pontchartrain began in 1951 and a contract was awarded for the bridge design in December 1953.

The bridge was built in a very short time in 1955-1956. The first pillars were placed on May 23, 1955. 4,482 bridge piers were built for the first bridge, each span was 56 feet long, 33 feet wide weighs 180 tons. The bridge consists almost entirely of identical parts and could therefore be manufactured elsewhere at a rapid pace. 2,235 spans were prefabricated and then loaded onto barges and transported to the bridge site and then hoisted in. The bridge was opened to traffic only 14 months after the first pillar on August 30, 1956. The first bridge is the present-day southbound bridge. The first bridge cost $30.7 million and was a toll road.

Construction of the second span

Due to the rapidly growing traffic in the 1960s and the road safety problems of such a long, straight two-lane road without landmarks (polder blindness), it was quickly decided to build a second bridge. Its construction started in June 1967 and was completed in just over two years from 1967 to 1969. Due to improvements in technology, spans of 84 feet were used here. Seven crossovers between the new and existing bridge were also constructed so that emergency services could turn around. The bridge deck of the second bridge was also wider at 46 feet. The second span was opened to traffic on 10 May 1969.

Later adjustments

A satellite image of the Lake Pontchartrain with the bridge in the middle.

The bridge has not been substantially modified after opening. The bridge has been hit a number of times, sometimes resulting in deaths. In 1960, 1964 and 1974 the bridge was hit and bridge segments collapsed. These were repaired within a few ways. In 1996-1997 400 bridge piers that were damaged were renovated. The toll was levied in both directions until 1999 and only southwards since then. Hurricane Katrina in August 2005 caused limited damage to the bridge, which was closed for three weeks for repairs.

Guinness Book of Records

The bridge had been listed in the Guinness Book of Records since 1969 as the longest bridge over water in the world. In 2011, the Jiaozhou Bay Bridge in China opened, which is 26.7 kilometers long and is part of a 41.6 kilometer connection across the Jiaozhou Bay near Qingdao. The entire length of the connection (including the parts at ground level on land) was mistakenly included as bridge length. Since then, the definition in the Guinness Book of Records has been amended to define the Jiaozhou Bay Bridge as the longest bridge over water (aggregate). In fact, this is incorrect because the parts that are not above water are not bridges and the Lake Pontchartrain Causeway at 38.4 kilometers still far exceeds the length of the Jiaozhou Bay Bridge, even if the short bridges are over land and a branch of the bridge. are included.

Road safety

The Lake Pontchartrain Causeway consists of two very long flyovers with no emergency lanes. This makes access for emergency services difficult in the event of an incident. In the past, 7 turning points were constructed between the two viaducts. Originally there was also a U-turn in both directions under the western bridge about 15 kilometers from the coast at Metairie. This was demolished in phases between 2006 and 2017. Because the bridge had no emergency lanes, emergency lanes of 300 meters in length were constructed at 12 locations in 2018-2020, for which new bridge piers had to be built. The bridge railing has also been raised so that vehicles can enter the water less easily.


The bridge is named after Lake Pontchartrain, which is actually an estuary or bay of the Gulf of Mexico and not a lake. The lake has an open connection to the sea, but is largely surrounded by land. The lake is named after Louis Phélypeaux (1643-1727), Count of Pontchartrain. The Château de Pontchartrain is located in France at La Tremblay-sur-Mauldre in the Yvelines department, on the west side of Paris. Louis Phélypeaux was a French minister during Louis XIV (Louis XIV), after whom La Louisiane ( Louisiana ) was named. The name Pontchartrain refers to a bridge over the River Mauldre to Chartres in western France.

Traffic intensities

In 2010, 43,000 vehicles drove over the bridge every day, which means that it is not overloaded.


The bridge is a toll road, the toll is $5 in cash and $3 with a tag and is charged south only. The company that manages the causeway issues toll tags, but the GeauxPass does not work on the Lake Pontchartrain Causeway.

Lake Pontchartrain Causeway, Louisiana

About the author