The Federal-Aid Highway Act of 1956 led to the construction of many highways in the United States in the 1950s and 60s. Some sections of Interstate 95 – a main north-south highway that runs from Florida to Maine and into Canada – were constructed during the 1960s, including the portion that goes through Wilmington, Delaware. Fourteen years later, in 1978, portions of the roadway and bridges were widened, and several on- and off-ramps were constructed. The Delaware Department of Transportation's (DelDOT) Restore the Corridor Wilmington is doing a significant amount of work on I-95 through Wilmington.“The Restore the Corridor Wilmington project is a high risk one for the department,” says Mark Buckalew, Chief of Construction and Materials for DelDOT. “We needed to make sure it went well.” The project was high risk due to its budget and the communication necessary to ensure it proceeded as planned.

The project includes nearly 3 miles of roadway. Part of that is the mile-long Wilmington viaduct, an elevated roadway that goes through the city. Buckalew called the repair of the viaduct the main gist of the project. “The viaduct portion was in bad shape. It offered drivers a poor ride and a high accident rate due to poor merge conditions.”

Nineteen bridges, including the viaduct bridges and the Brandywine River Bridge, are also being repaired as part of the project. Bridge rehabilitation involves deck repairs and replacement, spall repairs, sealing of the substructure and superstructure, barrier replacement, and painting of the steel girders. The repairs are expected to extend the bridges’ service life and avoid major and costly rehabilitation work for a minimum of 30 years.

The Brandywine River Bridge is a significant element of the work – 20 percent according to Buckalew. The team is adding a lane on the northbound side, which sees significant traffic.

The team demoed existing decks with high-pressure water. It took off 1.5 to 2 inches of deck. Besides being a quick way to remove bridge decks, “weak concrete comes out and we can see weak areas that need more attention,” says Buckalew.

Other project elements included resurfacing and repairing the roadway, replacing deteriorating concrete traffic barriers and roadway expansion joints, and improvements to lighting and signage.

DelDOT was determined to get the project done in two years. Finding a contractor who would commit to the schedule was a challenge. “Every contractor said they couldn’t do it expect for Kiewit Infrastructure,” Buckalew says. The contractor had recently completed a job in Delaware, so DelDOT was comfortable working with them and confident they could complete the work.

They utilized the CM/GC project delivery method, which puts a significant amount of the burden on the contractor. It also gives the general contractor more input as they come on board to finalize the last 10 to 20 percent of the plans and find ways to improve constructability. DelDOT chose this method because it provided the ability to work out constructability issues, slightly alter designs to provide greater efficiency for construction activities, and provided flexibility to alter details for a more cost effective design.

“Kiewit was very innovative and developed an aggressive schedule,” Buckalew says. It meant a great deal of coordination of people and equipment.

The plan was to put the northbound and southbound traffic in a contraflow pattern to free up one direction at a time. It took two weeks to shift traffic to the southbound after they worked on the northbound section first. This meant a drop in lane capacity, a challenge for a highway with an average daily traffic count of 100,000 vehicles, 10 percent of which is truck traffic.

DelDOT did a couple of things to prepare for the massive traffic adjustment. Before starting, the team rehabbed pavement on bypass roadways that the traffic could take so they could handle extensive loads. They also performed extensive outreach to inform the public of alternate routes.

Concern about the impact on the local public has continued through construction. This is particularly relevant since people live along the road. The team adjusted the schedule whenever possible to mitigate noise and is particularly careful about nighttime noise. They also kept everything wet to minimize the dust blown into communities. “We made sure to tell the public what’s coming and include them in key decisions about how we built this job,” Buckalew says.

To meet the aggressive schedule that Kiewit developed, the team had to move swiftly. The plan was to begin in the spring of 2021 and complete the project by the winter of 2022.

The team began making the necessary shifts during the third week of February 2021 to be ready to work when the weather broke. This first step was essential to meeting the aggressive schedule.

Buckalew and the team chose the night of February 26, 2021, to complete the traffic shift. This meant shutting down a section of I-95, a major inconvenience for users. The weather forecast that night called for snow at 3 a.m. Buckalew felt confident the team could complete the work before the snow hit. If not, the project wouldn’t complete on schedule.

Throughout the day, the weather forecast changed with the forecast for the arrival of snow getting earlier and earlier. The last prediction called for snow to arrive at 10 p.m. The team managed to complete the work that night even as the snow began to fall.

By March 1, they were working on the northbound side.

However, the challenges were not over. To reach the aggressive schedule, the team had to complete the northbound side and shift traffic to that side by two weeks before Christmas in 2021. The plan was to get everything shifted over during the winter of 2021 in order to do demo work through the winter and be ready to work on the southbound side by spring.

The team managed to get the work done and keep the project on schedule. All lanes were opened to traffic on both sides of I-95 by November 2022. Buckalew credits the entire team, “The women and men who worked on the project came to work, were dedicated, and put in their best efforts to make it happen.”

The project was paid for via an 80/20 split between the federal and state government. The budget for the project was $159 million. Because DelDOT was so pleased with the work Kiewit had completed, they added on some extra elements, including an additional barrier wall and extra paving. Buckalew credits the CM/CG process for keeping the project on budget.

With the project complete, drivers will enjoy a smoother and safer ride on a key route that serves Wilmington and beyond. The project will expand the lifecycle of the bridges, including the Brandywine River Bridge, for 30 more years.