Egg Harbor Township and City of Somers Point, NJ

Garden State Parkway Shoulder Widening Milepost 30–35

Client: New Jersey Turnpike Authority
Our Role: Design

Image of a highway with two lanes on each side and a swale in the middle.

As one of New Jersey’s busiest highways, the Garden State Parkway (GSP) is a vital connection between northern New Jersey and the Jersey Shore. To reduce congestion and improve safety, the New Jersey Turnpike Authority (NJTA) initiated a 50-mile widening program from South Toms River at milepost 80 to Somers Point at milepost 30.

For the milepost 30-35 segment, NJTA needed final design improvements to address critical safety concerns, upgrade aging infrastructure, and widen long-term asset structures to account for possible future improvements while minimizing environmental impact and traffic disruptions.

NJTA selected our firm to provide professional engineering services for final design improvements for the GSP shoulder widening from milepost 30 to 35 in Egg Harbor Township and the city of Somers Point. The project included:

Widening the northbound and southbound right and left shoulders.
Extending acceleration and deceleration traffic lanes at Interchange 30 to improve merging and exiting conditions.
Reconstructing and widening eight mainline bridges to improve vertical clearance, enhance structural integrity, and support future maintenance and roadway enhancements.
Constructing stormwater management facilities.
Implementing slope stabilization measures.
Relocating utilities.
Resurfacing the roadway.

Innovative Slope Stabilization Techniques
A key challenge was adhering to the NJTA-established disturbance limit set in the original 2008 approved permit design. This limit, approved by the New Jersey Department of Environmental Protection (NJDEP) and the Pinelands Commission, restricted the proposed limit of disturbance and impacts to environmentally sensitive resources. Any work beyond these boundaries would require new permits, which would significantly delay the project timeline.
The original permit design did not fully account for replacing the eight bridges, but updated project objectives required full bridge replacements. Raising the bridge approaches so each bridge could meet vertical under-clearance requirements left insufficient space to use a standard 2H:1V slope ratio for stable embankments without exceeding the disturbance limit.
To address this, the team developed:
- Innovative geogrid-reinforced slopes and turf reinforcement matting to stabilize embankments within the approved limit.
- A cost-effective alternative to retaining walls, which saved nearly $5 million and avoided triggering permitting delays.
Long-Term Flexibility for Future Upgrades
The project is designed to be adaptable in the future, incorporating features that support ongoing GSP improvements, including:
- Bridges with longitudinal girders allowing future re-decking in two stages while maintaining two 12-foot-wide travel lanes in each direction.
- Wider bridges and roadside berms to accommodate future roadway enhancements.
Community Considerations
The project utilized asphalt rubber open-graded friction course pavement along the Parkway mainline roadways, which absorbs vehicle noise through its high void aggregate composition to reduce noise impacts on nearby communities.
The project also addressed Atlantic County’s four roads that cross under the GSP:
- Mill Road.
- Zion Road.
- Steelmanville Road.
- Ocean Heights Avenue.
As part of the project’s improvements, each roadway was resurfaced, utilities were relocated to accommodate bridge replacement, and guide rail was installed to provide berm space between proposed bridge abutments.
The project limited construction work to daytime hours and imposed lower speed limits to reduce noise disruptions while keeping the highway open to traffic as part of the project’s traffic management strategy.
Environmental Stewardship
Environmental considerations were a key part of the project. The team worked within the pre-approved area to integrate solutions that would satisfy stringent environmental requirements of the Pinelands, including:
- Building 17 recharge swales and two detention/recharge basins within the pre-approved area to meet NJDEP and Pinelands Commission stormwater management design requirements without affecting regulated areas.
- Using weeping lovegrass for slope stabilization and long-term erosion control.
- Implementing erosion and sedimentation control measures approved by the Cape Atlantic Soil Conservation District to minimize dust and environmental impact.

Key Features

Widened northbound and southbound shoulders.
Extended acceleration and deceleration lanes at Interchange 30 to meet geometric design standards.
Reconstructed eight mainline bridges, incorporating features for future upgrades.
Wider berms and structures to accommodate future roadway enhancements.
Four Atlantic County roads upgraded to meet clearance standards.
Noise-reducing asphalt rubber open-graded friction course pavement installed on the Parkway roadways.
New recharge swales, detention basins, geogrid slopes, and vegetation for slope stabilization.

Outcomes

Enhances driver safety.
Supports ecological restoration and reduces maintenance costs.
Accommodates future re-decking with minimal traffic disruption.
Extended acceleration and deceleration lanes to allow for better traffic flow off of and onto the Parkway.
American Council of Engineering Companies of New Jersey, 2025, Distinguished Award.