Opportunity
The longest highway in New Jersey, the Garden State Parkway is also the busiest toll highway in the country. The Driscoll Bridge, which carries the highway over the Raritan River, marks the boundary between the metropolitan section to the north and the shore section to the south.
In 2008, the New Jersey Department of Environmental Protection designated contaminated parcels of land just south of the bridge as a Brownfield Development Area. The area is now being remediated as part of a waterfront development called The Point at Sayreville.
With 15 travel lanes, the Driscoll Bridge is the world’s widest highway bridge and one of the busiest, crossed by about 400,000 drivers each day. Traffic on the bridge and the Garden State Parkway is expected to increase even further with the completion of the development, which is planned to include 3 million square feet (278,000 square meters) of retail space, 837,500 square feet (77,800 square meters) of hotel space, 650,000 square feet (60,387 square meters) of offices, and 2,000 residential units.
Solution
In 2010, Mott MacDonald was retained as a key subconsultant to Stantec Consulting Services, to design a replacement bridge on the Garden State Parkway mainline that carries the seven southbound lanes of traffic over Chevalier Avenue and two ramps for the reconfigured interchange just south of the Driscoll Bridge that provides access and egress to the new waterfront development.
Mott MacDonald designed the new two-span replacement bridge structure, including performing the required seismic analysis, which uses pile foundations to support the solid wall pier and integral mechanically stabilized earth abutments.
We also performed extensive environmental services, including the following:
- Hazardous waste screening of the project site
- Preparation of hazardous-waste sections of the Environmental Constraints Report and Alternatives Analysis
- Preparation of hazardous-waste sections of the Executive Order 215 Environmental Assessment, needed to gain approval of the New Jersey Department of Environmental Protection
- Sampling and testing
- Development of plans for soil reuse and groundwater handling
Outcome
Together with the companion replacement northbound bridge and the new ramps completing directional movements missing from the originally constructed interchange, the project’s reconfigured interchange will allow traffic to now enter and exit the highway from all directional movements, helping ease congestion and facilitate access and egress to the new waterfront development.
The alignment of the new bridges was based in part on the need to minimize impact to adjacent wetlands. Demolition debris such as concrete, asphalt, and structural steel was recycled.
According to the Borough of Sayreville, the successful remediation and redevelopment of the Brownfield Development Area will “create jobs, revitalize the community, generate ratables, create recreation and open-space, and restore approximately 425 acres of heavily contaminated land that has lain vacant for decades.”
Improvements to Interchange 125 will help ensure the success of the new development while minimizing the impact on traffic and congestion.