Amidst the final phase of work for the 11-year, $320 million Route 72 Manahawkin Bay Bridges project between Stafford Township and Long Beach Island, New Jersey, “One of the main challenges is the need to have all travel lanes open during the summer season,” said Steve Schapiro, Spokesperson for the New Jersey Department of Transportation (NJDOT). “This limits construction on the roadway from mid-September through mid-May.”

Of course, weather conditions during those months can make work more difficult, but Route 72 provides the only way on and off Long Beach Island, a popular summer destination.

General Contractor C.J. Hesse, Inc., of Atlantic Highlands, New Jersey, began work on the project’s fifth and final contract in March 2021, making roadway and drainage improvements in Ship Bottom Borough on the island and Stafford Township on the mainland. Despite constrained workspaces and a few unexpected challenges, Schapiro expects construction to finish on schedule in December 2024.

Prior to the start of the overall project, the 50-year-old Manahawkin Bay Bridge and three trestle bridges over the Intracoastal Waterway experienced severe deterioration and required frequent repairs. With local population increasing and the shore area gaining in popularity, higher recreational and commuter traffic volumes caused chronic congestion on the bridges and access roads, hampering access for emergency vehicles.

To improve safety and ease the congestion, NJDOT began improvements to a 3-mile stretch of Route 72 in 2013. That included rehabilitating the existing bridges and building an additional Route 72 bridge between Long Beach Island and the mainland. The new structure carries two lanes of eastbound traffic, and the original Manahawkin Bay Bridge carries two lanes of westbound traffic. NJDOT divided the project into five separate contracts and already completed four.

NJDOT awarded C.J. Hesse the final $33.7 million, low-bid contract for parts 1A (Stafford) and 1B (Ship Bottom) in November 2020.

As they complete roadway improvements to increase mobility and safety, “The work area is constrained because of businesses and residents,” Schapiro said. “The high groundwater table also makes the roadway construction more challenging. However, these challenges were addressed in design, recognizing the constraints of the project area.”

In Stafford, crews are widening Marsha Drive to provide double left turn lanes onto Route 72 and adding a third lane in both directions of Route 72 near the intersection.

In Ship Bottom, the work will widen approximately 3,000 feet of Route 72 (locally known as 8th and 9th Streets) and three crossroads. Two-way traffic will be restored along two of those crossroads (Central Avenue and Long Beach Boulevard). In addition, five traffic signals will be reconstructed, and a new traffic signal will be installed at the intersection of 8th Street and Long Beach Boulevard.

To reduce frequent flooding and improve access during heavy rainfall and high-tide events in Ship Bottom, a new storm drainage system and new outfalls will be installed on 8th and 9th Streets.

“The drainage system was designed so it doesn’t require pump stations,” said Jeffrey Bassano, Resident Engineer for NJDOT. “Instead of a mechanical system, it uses gravity.”

As with most projects, not all the challenges could be anticipated in the design phase. For instance, during construction of the 8th Street outfall, the project team learned of a nearby, newly installed water supply that feeds Long Beach Island.

“To avoid any potential service outages, it was necessary to get the location of the waterline ahead of the outfall installation,” Bassano said. “We tried to find the waterline using traditional methods such as metal detection, tracer wire, as-built plans, and test pits, but those were all inconclusive.”

The project designer recommended an Inertial Measurement Unit (IMU), an emerging technology that can locate pipes and conduits as small as 2-inch diameter when traditional location methods are unsuccessful.

“The IMU was inserted into one end of the water service and traveled through the pipe recording its location,” Bassano said. “When the IMU was removed, the data it collected was uploaded and we were able to determine the waterline’s exact location using the project’s coordinate system.”

That solved the problem for outfall installation, but another ongoing challenge prompts occasional plan changes.

“Utility relocation has been difficult as the powerlines have to be perpendicular and there have been unexpected underground obstructions and conflicts that require relocating some of the poles,” Bassano explained.

In addition to the current work on Contract 1A and 1B, the overall project included construction of the new, 2,400-foot-long Manahawkin Bay Bridge parallel to and south of the existing Route 72 bridge. Completed in 2016 under Contract 2, the new structure adds the safety of a redundant route on and off Long Beach Island in case of emergency or future bridge maintenance.

Contract 3, completed in 2019, rehabilitated two of the trestle bridges between the mainland and the island.

The existing steel girder Route 72 bridge – locally known as the Manahawkin Bay Bridge, Causeway Bridge, or Dorland J. Henderson Memorial Bridge – was reconstructed in Contract 4. Crews removed and replaced the entire superstructure, repaired the substructure and approach roadways, and rehabilitated a nearby trestle bridge. Substantially completed in 2019, that work received the 2020 America’s Transportation Award for best quality of life/community development in a medium-sized project.

Also completed in 2019, Contract 5 – the Cedar Bonnet Island Habitat Restoration and Management Plan – received the Federal Highway Administration Environmental Excellence Award.

Under the $9.6 million federally and state-funded environmental mitigation work, NJDOT and the U.S. Fish and Wildlife Service created an environmental trail providing the first public access to the Edwin B. Forsythe National Wildlife Refuge on Cedar Bonnet Island, which lies between Long Beach Island and Stafford Township.

In addition, “That project used an innovative approach to help improve Barnegat Bay water quality while meeting New Jersey Department of Environmental Protection Stormwater Management rules,” Bassano said.

That included wetland creation, mitigation for freshwater wetlands, and retrofit of two existing stormwater basins.

The overall project also increased multimodal options. The rehabilitated Manahawkin Bay Bridge now features a sidewalk connecting Stafford and Ship Bottom, while the new bridge includes connections to communities and points of interest along the way. Thirteen-foot outside shoulders on the twin Manahawkin Bay Bridges and 6-foot shoulders on the trestle bridges allow bicyclists to travel between Long Beach Island and the mainland. In addition, the project improved public access to the waterfront, including areas for fishing and crabbing.

At the groundbreaking ceremony for the final contract, New Jersey Governor Phil Murphy said, “With new lanes that will be constructed at-grade and drainage and other improvements that will be made underground, the entirety of this project is part-and-parcel of our overall goal of ensuring the safe, modern, and resilient infrastructure that our state deserves and needs.”