I-95 Piscataqua River Bridge Rehabilitation

I-95 Piscataqua River Bridge Rehabilitation

Kittery, Maine and Portsmouth, New Hampshire
United States
Piscataqua River Bridge

TYLin was the prime consultant for the rehabilitation of the I-95 Piscataqua River Bridge connecting Portsmouth, New Hampshire, with Kittery, Maine.

The I-95 Piscataqua River Bridge is the busiest and most important bridge in Maine. The 4,503-foot-long through-arch structure carries six lanes of I-95 across the Piscataqua River. As the only interstate highway connection to Maine, it is vital to freight traffic, commuters, and tourists. Approximately 78,000 vehicles cross the bridge each day. In the summer season, daily traffic counts rise to over 130,000, leading to regular traffic jams.

With the goal of improving safety while keeping the bridge in service far into the future, the Maine Department of Transportation (MaineDOT) tasked the project team with identifying a way to move more traffic through the corridor using the existing bridge. TYLin proposed an intelligent transportation system (ITS) to dynamically use the emergency shoulders as a fourth lane in each direction. This project rehabilitated the structure and readied it for the ITS installation, which will greatly improve traffic flow.

The rehabilitation centered on the massive bridge. In addition to the 756-foot-long main truss arch span and 294-foot-long back spans, there are 33 steel girder approach spans. The bottom chord of the truss is 135 feet above the Piscataqua River. To facilitate traffic flow, the interstate north of the structure was widened for approximately 2 miles.

Despite being the first major rehabilitation since the bridge’s construction in 1972, the greatest challenge was keeping traffic and commerce moving freely every day of construction. Working closely with MaineDOT, the New Hampshire Department of Transportation, and the Maine Turnpike Authority, TYLin evaluated traffic levels at the site for every hour of every day of the year. The team then developed a detailed maintenance of traffic scheme, with specific lane closure windows for each day of the year. TYLin created traffic visualization and modeling to develop an intricate, incentivized traffic control plan identifying when and where rehabilitation work could be performed with minimal traffic disruption.

To maximize worker safety and minimize traffic disturbance, the team mandated use of movable temporary concrete barriers. The Road Zipper System® allowed lanes to be opened and closed quickly - multiple times each day - so the focus of work could shift based on traffic. This approach is new nationally and had never been utilized in Maine or New Hampshire. Any significant disruption to traffic would have had an immense negative impact on businesses, created loss time costs for travelers, and increased the potential for traffic crashes.

The traffic control approach worked flawlessly. The project was completed ahead of schedule with minimal impact on the public, no contractor claims, and all project goals achieved. The rehabilitation enhances the safety and confidence of the traveling public and ensures the iconic bridge’s continued use for many years.

Project Highlights:

  • The project encompassed full deck replacement with a high-performance waterproofing membrane and asphalt wearing surface.
  • The bridge was outfitted with a robust new drainage system with 256 bridge drains.
  • The rehabilitation included joint replacements, concrete and catwalk repairs, the addition of solid concrete parapets, and new electrical and lighting systems.
  • TYLin performed construction support services and provided an Assistant Resident Inspector and a Senior Inspector for construction inspection services.

Images Credit: Sky Rover Imaging


National Recognition Award, 2023 Engineering Excellence Awards, 2023
American Council of Engineering Companies (ACEC)
Gold Winner, 2nd Place, Engineering Excellence Awards, 2023
ACEC New Hampshire
Honor Award for Engineering Excellence for Traffic Management and Planning, 2022
ACEC Maine
#7, Top 10 Bridges, 2022