Interstate 10 Twin Bridges - Lake Pontchartrain
Westbound on the I-10 Twin Bridges crossing Lake Pontchartrain. - 10/17/2001
An $733 million project replaced the damaged Twin Bridges across Lake Pontchartrain between June 2006 and September 2011. The new bridges were constructed just east of the 1965 spans as traffic continued to use the original bridges. Eastbound traffic shifted to a combination of the new east and westbound bridges on July 9, 2009 while westbound traffic remained on the old bridge. This configuration lasted until March 12, 2010, when eastbound traffic moved entirely onto the new bridge. By April 7, 2010, westbound traffic moved from the 1965 eastbound bridge to a combination of the new east and westbound bridges. The emergency crossovers near the Twin Bridge ends were used to shunt traffic from one bridge to the other during the temporary configuration.
Two segments of the 1965 Twin Bridges were retained near the North Shore at Slidell for use as fishing piers. A 700 foot long wooden bridge connects the old bridges, now named the St. Tammany Fishing Pier, to the shore at Howze Beach Road. The public fishing facility opened on May 18, 2012.
West - 1965 bridge
Interstate 10 originally crossed the eastern reaches of Lake Pontchartrain along a pair of two lane concrete viaducts opened in 1965. Damage to the bridges as a result of Hurricane Katrina closed I-10 fully between August 29, 2005 and October 14, 2005. Four-lane capacity was restored on January 5, 2006.
11/23/08
A pair of temporary metal truss spans were used along Interstate 10 westbound where the concrete deck portions toppled by Hurricane Katrina were damaged beyond repair. Similar metal spans were used along I-10 over Escambia Bay in Pensacola, Florida, but those only supported one lane of travel while the Louisiana sections provided two lanes.
06/10/06
Cresting over the Lake Pontchartrain navigation channel along Interstate 10 westbound. The 2011-completed Twin Bridges to the left crest at 80 feet above the lake while the original bridges did at 65 feet.
11/23/08
06/10/06
The new Twin Bridges to the southeast travel 30 feet above the lake while the original spans traveled just nine feet. The eastbound span suffered less damage during Katrina and needed no temporary spans.
11/23/08
The only guide sign left in place by Hurricane Katrina for Exit 254 (U.S. 11) was the two mile entry along the Lake Pontchartrain bridge westbound.
11/23/08
The second temporary truss span was located near the north shore of Lake Pontchartrain at Irish Bayou. Strong northwesterly winds fueled a storm surge that toppled many of the westbound bridge slabs during Hurricane Katrina. Speed limits overall on the bridges remained at 60 mph with 45 mph zones posted at the narrow metal decked sections.
06/10/06
Temporary concrete barriers blocked off the original guard rail along the western side of Interstate 10 for the most part with the exception of the Irish Bayou bridge approach.
06/10/06
Katrina's winds claimed the U.S. 11 guide sign at the gore point for Exit 254.
11/23/08
West - 1965 bridges after the switch
When eastbound traffic shifted entirely to a combination of the new Twin Bridges, westbound traffic moved to the original eastbound bridge.
10/24/09
West - 2009 bridges
Westbound traffic shifted to a combination of the new east and west Twin Bridges on April 7, 2010. While this configuration was in place demolition was underway involving the original eastbound span and the approaches in both directions.
06/09/10
What is now an emergency crossover was used to connect westbound traffic from the completed eastbound span to the partially completed westbound span to summer 2011.
06/09/10
Lowering from the crest of the new westbound Twin Bridge, with the 1965 spans still in place to the northwest.
06/09/10
A new sign bridge installed that displays the two mile guide sign for U.S. 11 (Exit 254).
06/09/10
Approaching Point aux Herbes, traffic along the westbound bridge shifted to the eastbound bridge at what is now the last emergency crossover heading south.
06/09/10
All traffic shifted to the eastbound Twin Bridges as work continued on the south side approach. Work here was completed on August 15, 2011.
06/09/10
East - 1965 bridge
Interstate 10 eastbound nears the 1965 twin bridges over Lake Pontchartrain between Point Aux Herbes and Eden Isles in St. Tammany Parish. The bridges carried four lanes of travel between Irish Bayou and Slidell.
06/10/06
Hurricane Katrina's storm surge sent many of the concrete bridge deck slabs into the lake. Crews salvaged as many of the spans that they could and used them to repair the eastbound span.
06/10/06
Descending from the navigation crest of the eastbound twin bridge of Interstate 10. Since crews were able to rebuild the eastbound span with original concrete decks, the bridge remained open with its original 60 mph speed limit.
06/10/06
A view of the North Shore coastline and city of Slidell from the 65 foot crest of the 1965 eastbound Lake Pontchartrain Bridge.
06/10/06
The previous two mile guide sign for Exit 261 was blown into the Lake during Hurricane Katrina.
12/28/02
One mile south of Exit 261 on the former Interstate 10 eastbound bridge.
06/10/06
East - 2009 bridge
Eastbound traffic shifted from the 1965 bridge to a combination of the new Twin Bridges on July 9, 2009. This was partly because the old bridges were still in the path of the eventual westbound bridge approaches.
10/24/09
A short distance from Point aux Herbes was the shift from the eastbound to the westbound bridge. An emergency crossover was created from this connection at the end of construction.
10/24/09
Posts for the U.S. 11 interchange of Interstate 10 westbound were in place as the bridge functioned for eastbound.
10/24/09
Cresting over Lake Pontchartrain over a combination of the new and older bridges.
10/24/09
Approaching the north shore, eastbound traffic shifted from the west to eastbound spans. An emergency crossover was created from this temporary connection as well.
10/24/09
A new overhead assembly for Exit 261 was in place ahead of the Twin Bridges end. This sign was replaced already by 2012.
10/24/09
Photo Credits:
- Andy Field: 12/28/02, 11/23/08
- Alex Nitzman: 06/10/06
- Brent Ivy: 10/24/09
- Alex Nitzman, Lou Corsaro: 06/09/10
Page Updated Monday September 24, 2012.