The Interstate 295 Southbound Reconstruction Project's fourth and final $34 million phase to modernize the approach road system, improve efficiency and enhance safety is progressing on schedule.

"The need for the I-295 Southbound Reconstruction Project is primarily a function of outdated design and poor pavement conditions leading to reduced safety along the corridor," says Brent C. Van Lith, Project Engineer II with the Delaware River and Bay Authority (DRBA) in New Castle. "The last of these deficiencies will be corrected in this final phase of improvements."

Adapting to Current Standards

The approach roads and ramps were built in the late 1950s. The authority decided to update them to comply with current federal and state highway standards. The southbound I-295/U.S. 13 interchange experiences traffic congestion where four through-lanes decrease to two lanes. Drivers often weave through traffic, increasing risks for accidents.

The work on this reconstruction project from Landers Lane to I-95/I-495 includes adding a third mainline lane through the U.S. 13 interchange to provide lane continuity and increase safety operations; new asphalt pavement; replacing superstructure and making substructure repairs on I-295 bridge over U.S. 13; lowering I-295 southbound under I-95 northbound and I-495 northbound; removal of a left-hand merge and replacement of it with a right-hand merge; and guardrail and shoulder upgrades.

This final phase of construction work covers both DRBA and Delaware Department of Transportation (DelDOT) portions of I-295. For ease of administration, DRBA is performing construction on the full length of the highway, and DelDOT will reimburse the authority for the DOT's portion of work, approximately $7 million. Additionally, a portion of the Industrial Track Greenway between New Castle and Wilmington will be completed, including a 265-foot-long, 10-foot-wide, illuminated tunnel under I-295.

"The general public is going to be happy with the results," said Jim Salmon, Public Information Officer for DRBA. "We are increasing throughput by 50 percent. We are looking forward to December 2018, when we can open it to the public."

When this highway work finishes next year, the authority will have invested more than $90 million to improve the region's infrastructure during the course of the I-295 Delaware Memorial Bridge Approach Road Rehabilitation program, which started in the late 1990s. The third phase finished in 2011. The DRBA owns and operates the Delaware Memorial Bridge, two ferry crossings and two airports. All DRBA operating revenues are generated through the bridge, ferry and airport facilities.

Construction Activity and Challenges

RK&K of Baltimore is the design engineer for the project. Mumford and Miller Concrete of Middletown, Delaware, was awarded the $34 million contract. Work began in February 2016. The project is about half finished.

"The contractor has kept up the schedule even though we have had several minor setbacks that added work to the contract," Van Lith says. "The minor setbacks were unforeseen. The contractor mostly worked through the schedule to work at multiple locations at once."

Four bridges are being removed and not being replaced, as they were configured for the old roadway and two were over abandoned railroad lines. The reconstruction of the I-295 bridge includes new steel girders.

Maintaining traffic flow has been a high priority and a challenge. Two southbound mainline through lanes have been maintained at all times. The authority considered lane patterns and added signs before and after traffic shifts to make sure that traveling through the work zone is as easy as possible for commuters as well as infrequent users. It also reduced the speed limit to 40 mph.  

"We are adjusting the times of day and seasons we are working to have the least amount of impact as possible," Van Lith says. "We have made a number of changes for ease of traffic, and addressed a number of comments and suggestions,"

Safety is a top priority, and to date, the job has had no lost-time accidents.

Testing and Research Opportunities

Engineers at the University of Delaware are working with the DRBA on two destructive testing opportunities on bridges slated for removal. DRBA had worked with the university on prior projects and when this one came along, the authority reached out to the university to offer the opportunity for more testing. DRBA will pay the contractor for participating in the testing.

In the first test, the contractor will be cutting one of the girders to see how the remaining girders take up the load, Van Lith explains. Most bridges have redundancy, he says. The computer models predicting how the bridge will behave are not perfect and not real world, he adds.

"It's always good to have real data and real examples to look at and test your models," Van Lith says. "When they cut the one girder, they will see if they see the distribution of forces they predicted."

In another test, the university engineers will continuously load one section of the bridge until it fails. Van Lith describes the process as bending and stretching, but not collapsing.

"It's good information, because bridges are highly complex systems," he says. "It's good to get their hands on real-life examples."

The university will wire the bridge with sensors and strain gauges to monitor forces and movement.

"The data gathered from forcing a bridge member to fail allows the engineers to test their models to more accurately predict how these complex systems behave," Van Lith says. "It's a good opportunity, and we are willing to help out."

Van Lith adds that multiple facilities exist for testing road pavements in the real world, but few exist for bridges. That created an opportunity to use these bridges to advance the engineering science.

"It's been a lot more work than most contracts, but when you see traffic moving smoothly, it's very satisfying to have done a good job in a challenging situation," Van Lith says.