The Pennsylvania Department of Transportation’s (PennDOT) Interstate 95 (I-95) Central Access Philadelphia (CAP) project team has been working hard throughout the summer to deliver a new public space for the City of Brotherly Love. The $329 million CAP project involves the construction of a new bridge structure connecting Front Street to the Delaware River waterfront over I-95 and Columbus Boulevard. The structure will extend north from Walnut Street to Chestnut Street. Atop the bridge structure, PennDOT will build the new 11.5-acre Park at Penn’s Landing, featuring gardens, play areas, a mass-timber pavilion, and more. The CAP project will also create a new signature pedestrian bridge over Columbus Boulevard. This bridge will provide direct access to the Delaware River Trail from the existing South Street bridge over I-95.

Spotlighting Steel

In June, PennDOT’s team installed the project’s first set of steel beams over I-95. The 80 beams stretch east from Front Street across I-95’s southbound lanes to a new pier in the highway’s median. Specialized two-part trailers carried these oversized beams one at a time from their manufacturer in Lancaster, PA, more than 70 miles to the project site on I-95. There, using cranes that have towered over Penn’s Landing throughout the summer, the contractor, Buckley & Company, Inc., lifted the beams into place during five weeks of overnight road closures.

“Erecting 80 steel beams as quickly as the contractor did is a logistically challenging activity,” says Senior Project Manager Frank Bonito, who is leading Hill International’s construction management team on the CAP project. “Even though the beams are being manufactured relatively close to the city, they have long lead times, as well as specialized transportation and staging requirements. Their installation also required overnight road closures of I-95 to bring the beams in quickly, pick up the beams by crane, secure them in place, and then make everything safe for the reopening of the highway for morning traffic. However, PennDOT, Buckley, and the whole team have done a great job keeping the work on track. Installing the first set as planned is a testament to that.”

Next year, Frank says, Buckley will hoist two additional sets of beams into place. The first will traverse I-95’s northbound lanes to another pier between Columbus Boulevard and I-95, currently under construction, and the second will cross Columbus Boulevard to a new abutment, for which preliminary siteworks are underway. After all the steel is in place, concrete pours will complete the CAP project’s deck structure and allow park construction to proceed.

Other Key Developments

While the installation of the first set of steel beams represents a crucial milestone for the CAP project, PennDOT’s project team has also been working on less-visible scope items to keep the infrastructure project moving forward and limit disruptions to commuters, bicyclists, and pedestrians, as well as the area’s business and residents.

Safety First

With the first set of beams in place, the team installed wooden shielding to protect drivers from falling debris. Temporary fencing, barricades, and signage clearly mark new bike lanes and pedestrian pathways, as well as new traffic patterns along Columbus Boulevard and I-95. Fencing also helps secure the work sites. In addition to scheduling road closures from 11 p.m. to 5 a.m. on weekdays to limit traffic disruptions, PennDOT continues to share regular updates about highway lane closures to keep the public informed.

Deep Foundations

Passersby might miss some of the other large-scale works taking place on site. For example, PennDOT’s team is drilling holes approximately 6 feet in diameter and up to 150 feet deep for the installation of caissons between I-95 and Columbus Boulevard. Comprising steel casings filled with reinforcing steel bars and filled with concrete, these caissons will serve as foundations for another pier to support the CAP’s deck structure. Working closely with the design consultant, Pennoni, the project team is performing tests to gauge pressure, compression, and other geotechnical conditions at depth before installing the rebar frames and pouring the concrete.

A Lightweight Solution

The team is also executing siteworks in preparation for a new U-shaped embankment on the riverfront. At the rounded side of the U, a new abutment will receive the steel beams on the east side of Columbus Boulevard. From the abutment, the embankment will slope down to the river. Concrete retaining walls with pile foundations are currently in place on the northern and southern boundaries of the embankment. The outward-facing sides of the abutment and southern retaining wall also include a distressed, bleached wood design feature appropriate for the park’s riverfront location adjacent to Philadelphia’s Independence Seaport Museum.

For embankment fill, the project team is using foam glass aggregate, the same material PennDOT used during the emergency reconstruction of a collapsed section of I-95 in 2023. While more expensive than other fill options, the material is lightweight. “Working along the river, you want to avoid overloading the existing soils,” Frank explains. “Other types of fill would have been prohibitively heavy and could cause settlement issues. Given that, the foam glass mound is the cost-effective option.”

Frank adds that the gritty foam glass interlocks as it is placed, providing additional site stabilization. Despite the material’s light weight and high stability, the amount of fill will make the embankment very heavy. So, before the foam glass is in place, the project team will preload the site and monitor it for several months while measuring any settlement.

Office Work

A few blocks to the south, near the project team’s field office, Buckley has already installed piers that will hold up the new South Street Pedestrian Bridge and has established plans for laying down and hoisting the bridge structure into place.

Also at the field office site, manufacturers are setting up mockups of project features for review, such as the fencing to go around the sides of the park. This gives the project team an opportunity to review the product and comment on specifications and quality. Once approved, the mockups give inspectors reference points when they review work installations.

Trending Towards Success

“Project success comes down to managing each scope item, whether that’s the installation of steel beams or the installation of fencing around a small work area,” says Frank. “Each item, no matter how small, requires logistical planning, scheduling, cost tracking, quality control, and dedicated staff. We also have to coordinate with neighbors, the public, local authorities, and other project stakeholders. Managing these interfaces is one of Hill’s key responsibilities on the project.”

In addition to regular outreach to keep drivers aware of road and lane closures, PennDOT and Hill coordinate with utility companies that own assets in the project area; business owners and residents on Front Street and Columbus Boulevard; the Philadelphia Belt Line Railroad (PBL), owner of the active rail line in the middle of Columbus Boulevard; construction crews working on the adjacent Market Street Old City improvement project; the Delaware River Waterfront Commission (DRWC), the nonprofit responsible for stewardship of the waterfront and various waterfront attractions, such as Spruce Street Harbor Park, Independence Blue Cross RiverRink, and, when complete, the Park at Penn’s Landing; and even the U.S. Navy and Marine Corps as the organizations plan parades and other festivities along the Delaware River to celebrate their 250^th birthdays.

“Each stakeholder has different needs,” Frank goes on. “For the businesses, we’re providing signage to make sure people know that parking is still available. There isn’t too much overlap with the project on Market Street, but when either team has equipment coming in or is dropping off materials, we’ll get in contact and make sure there’s enough space for both of us to operate. With the Navy and the Marines, we’re going to clear enough space for guests to safely walk along the esplanade and enjoy the naval parade.”

With their proactive coordination approach, PennDOT’s team can make sure stakeholders are up to date, manage expectations, field concerns, and prevent conflicts. This helps keep the project trending towards success.

Coming Soon

Many of the CAP project’s most exciting features are still on the way. Once the deck is complete, PennDOT’s and the DRWC’s teams will be able to start creating the Park at Penn’s Landing. In addition to flexible green spaces filled with trees, gardens, and lawns, the park will feature a mass-timber pavilion with a café, playground equipment, fountains and a water play area, an amphitheater and stage, interconnected pathways, a variety of seating options, and more. The Irish and Scottish Memorials will also return from their temporary location at Foglietta Park—prior to the I-95 CAP project, the bronze statues were located at the intersection of Front and Chestnut Streets. In addition, the DRWC plans to relocate the Independence Blue Cross RiverRink ice rink from its current location north of the CAP project site to the new park.

PennDOT is collaborating with the DRWC on lighting and security strategies to help ensure safety and comfort for parkgoers. Sturdy, lighted fencing around the park’s perimeter will also contribute to park safety.

Beneath the park, PennDOT will fill the new Columbus Boulevard tunnel with lights and other design features to promote safety and comfort for pedestrians, bicyclists, and drivers. The team will also install an elevator and staircase along the southern retaining wall so that pedestrians can easily access the park from Walnut Plaza and Columbus Boulevard.

Also along the southern retaining wall, PennDOT will rebuild the walkway connecting Columbus Boulevard to the esplanade, the Independence Seaport Museum, and the RiverLink Ferry, which provides convenient access to attractions along the Camden, NJ, waterfront.

Other planned roadway reconfigurations include the extension of Chestnut Street and the reconstruction of several concrete segments of the Market Street loop bridge. This will allow motorists and bicyclists headed east on Chestnut to travel over I-95 and Columbus Boulevard alongside the park and loop onto Market Street’s westbound lanes. The bridge structure’s northernmost steel spans are specially designed to receive automobile traffic. PennDOT also plans minor adjustments on the streets surrounding the park, encompassing pavement reconstruction, weeding, drainage improvements, and more as needed.

The Big Picture

As early as 2030, the I-95 CAP project will deliver a new park in one of the city’s most scenic neighborhoods, allowing Philadelphians and visitors to come together and enjoy a wide variety of recreational activities in a safe, comfortable public space. However, PennDOT’s project will deliver much more than a park. The Park at Penn’s Landing will expand upon and deepen the city’s connection to existing public, commercial, and residential spaces all along the Delaware River. The project is also an impetus for continued investment and development throughout Penn’s Landing. Indeed, at a groundbreaking ceremony for the project in September 2023, former Philadelphia Mayor Jim Kenney forecasted a $1.6 billion return on investment over the next 25 years.

“Highway cap structures are a great solution for reclaiming urban spaces for public use without reducing our roadway capacity,” Frank concludes. “They can reconnect communities divided by highways and promote public health by incentivizing walking and biking. They can provide additional space for concerts, sports, and other important community events. Especially when the surface is used as green space, highway caps can restore habitat for native species and reduce the urban heat island effect. They can spur economic development. With the I-95 CAP project, PennDOT is demonstrating how state transportation agencies can lead the way and improve the quality of life in our cities.”

Frank Bonito can be reached at [email protected]. To learn more about Hill International’s involvement on the I-95 CAP project, please visit: https://www.hillintl.com/project/i-95-central-access-philadelphia-project/.