Located in southeast Louisiana, St. Tammany Parish is one of the fastest-growing parishes in the state. The parish has a population of approximately 270,000 people and has been growing dramatically since 1990. More growth is expected. To keep up with the population growth, the Louisiana Department of Transportation and Development (DOTD) is working on widening I-12, a major roadway in the area.In 2020, the average daily traffic count along the stretch of I-12 that is being widened was more than 80,000 vehicles. DOTD estimates show that number could grow to just over 110,000 by 2036. The average daily traffic count for the segment from LA 21 to U.S. 190, which is part of construction plans, was 96,000 vehicles in 2020 and is projected to reach just under 126,000 vehicles by 2040. Even at the current traffic levels, the interstate is congested.

In addition to the need to helping the commute of local motorists, the route expansion will have a national benefit. This is because I-12 is part of a vital freight corridor that connects Florida to Texas.

Besides impediments to the flow of traffic and the national ramifications, there are safety issues along this stretch of road. Multiple accidents have occurred along the stretch, including a 2018 incident that left four people killed and others injured. Local residents view the stretch of interstate as dangerous.

The DOTD is widening a 7-mile stretch of I-12 from four lanes to six lanes. The project is being completed in three segments. There are two segments currently under construction, while the third segment has not been bid yet.

As part of the first segment, just over 3 miles of the stretch are being widened. Other elements of the first segment include an asphalt overlay of the existing lanes, installation of a concrete median protection, and widening of three bridges.

In the other current segment, a little more than 4 miles of interstate will be widened. Similar work is being done in this segment, including widening the pavement surface into the median, overlaying the existing lanes with asphalt, and installing concrete median protection. In addition, one bridge is being widened.

The Tchefuncte River, which is named after a Native American tribe that inhabited the area between 600 B.C. and 200 A.D., is approximately 70 miles. The river runs between Madisonville, Louisiana, and Lake Pontchartrain, where it eventually drains.

I-12 passes over the Tchefuncte River, a navigable, scenic river. Permits had to be obtained from the Louisiana Department of Wildlife and Fisheries – due to it being a scenic river – and also from the United States Coast Guard because it’s a navigable waterway.

“All permits and environmental considerations were addressed prior to beginning construction of the bridge,” says Chris Welty, a Public Information Officer for DOTD. Securing permits for projects prior to going to bid is standard procedure for DOTD.

Widening the bridge required the team to use 54-inch cylindrical piles as they match the existing structure piling design.

JB James Construction is a full-service heavy highway and bridge contractor based in Baton Rouge. They are serving as the prime contractor on the second segment of the project. The company has worked on DOTD projects previously and were selected based on the low bid process. A different contractor, James Construction Group, is working on the first segment of the widening.

The total construction cost for the I-12 widening is nearly $114 million. Segment two is budgeted at slightly over $59 million. A significant amount of the funding for the project – $25 million – was paid for via a federal BUILD grant. This is the maximum BUILD grant award amount. According to the USDOT, criteria for BUILD grants “include safety, economic competitiveness, quality of life, environmental sustainability, state of good repair, innovation, and partnership.”  

The BUILD Grant funds only apply to the stretch from LA 21 to US 190. The remaining funds are coming from a variety of sources, including $7.2 million from St. Tammany Parish, $22.3 million from other federal sources, and $4.6 million from the state.

One segment of the project is ahead of schedule and the other segment is very close to being on schedule. Segment one of the project began in the spring of 2020 and is expected to be complete by the end of 2022. The second segment began in the fall of 2020 and construction is scheduled to be complete by the summer of 2023. The final phase has yet to be scheduled.

With the significant growth in population that St. Tammany Parish has already experienced as well as continued growth, infrastructure needs to keep up. This project will help the area do that. “Once complete, the project will ease congestion and allow motorists and commerce to flow more easily,” says Welty.