Maine’s second representative on our Top 10 list is another crucial bridge.
The Piscataqua River Bridge is the busiest bridge in the state. As the only interstate highway connection between Maine and the rest of the country, the structure is vital to freight traffic, commuters, and tourists. The daily bridge traffic ranges from 78,000 vehicles a day to as many as 130,000 depending on the season.
This 4,503-foot-long structure opened to traffic in 1972 and carries six lanes of Interstate 95 across the Piscataqua River between Kittery, Maine, and Portsmouth, New Hampshire. The bridge is the only fixed crossing of the Piscataqua River in the vicinity. The structure is jointly owned by the Maine Department of Transportation and the New Hampshire Department of Transportation, with the north approaches owned by the Maine Turnpike Authority (MTA).
In 2015, MaineDOT, with support from NHDOT and MTA, selected TYLin to evaluate the structure, design a comprehensive rehabilitation and the widening of the north approaches, and identify a way to move more traffic through the corridor using the existing bridge. The goal was to improve safety and mobility while keeping the bridge in service far into the future.
TYLin proposed an Intelligent Transportation System (ITS) that will use the shoulders as a 4th lane in each direction during peak travel times.
“This was an enormous project,” said Daniel Myers, project manager at TYLin. “Most of the work efforts were straightforward from a technical perspective, but the sheer scale and thus the required manpower meant that few contractors could even attempt the project. This led to a Massachusetts contractor, SPS-NE, winning a MaineDOT-led major project for the first time in many, many years.”
The project posed three distinct challenges: The enormity of the project site, the amount of rehabilitation work required, and the need to safely maintain traffic throughout the entire project.
Beside the 756-foot-long main truss arch span and 294-foot-long back spans, there are 19 steel girder approach spans on the New Hampshire approach and 14 steel girder approach spans on the Maine side. The bottom chord of the truss is over 135 feet above the Piscataqua River, which is navigable and sees steady shipping traffic beneath the bridge. Beyond the bridge, the interstate needed to be widened for approximately 2 miles to the north of the structure.
While minor repairs had been performed previously and the bridge had been painted once, no comprehensive rehabilitation had been done to this critical structure since it opened in 1972. The huge traffic volumes and harsh northeastern winter conditions had taken their toll on the structure.
The concrete bridge deck was the project team’s biggest concern. The overhang portions of the deck needed full replacement, including the median overhangs on the 33 steel girder approach spans. The remaining portions of the deck needed comprehensive repairs.
“We ran [ground-penetrating radar], calibrated with a series of cores, to determine how bad the deck was beneath the asphalt pavement,” Myers said. “The overhangs were in bad shape, but the interior portions of the deck weren’t too bad. The asphalt overlay had been replaced in the 1990s.”
MaineDOT was anticipating a very stressful construction period, with traffic issues leading to public outcry and pressure. That never occurred. A movable temporary concrete barrier was used to rapidly open and close lanes daily to maximize the work zone available. With this rapid deployment ability, the closures could be fine-tuned to the exact traffic patterns at the bridge site.
Working closely with the bridge’s three owners, TYLin evaluated the traffic levels at the site for every hour of every day of the year. The team then developed a detailed maintenance of traffic (MOT) scheme, with specific lane closure windows for every day of the year.
The MOT scheme worked exceptionally well. The contractor (SPS New England) provided an exceptional team that handled the project professionally and diligently. Through the teamwork and excellent construction management team provided by MaineDOT and supported by TYLin, there were no claims on the project. R&B
Project: Piscataqua River Bridge Rehabilitation
Location: Kittery, Maine and Portsmouth, New Hampshire
Owners: Maine Department of Transportation and New Hampshire, the north approaches are owned by Maine Turnpike Authority Department of Transportation
Designer: TYLin
Contractor: SPS New England
Cost: $52.6 million
Length: 4,503-foot-long bridge plus two miles of approach roadway
Completion Date: March 2022
