The replacement of the 100‑year‑old Portal Bridge in New Jersey is bringing two month‑long periods of reduced service as NJ Transit and Amtrak begin major construction on the busy Northeast Corridor.

Agency leaders say the bridge is the least reliable part of the Amtrak‑owned corridor and that the new structure will improve service for decades. But they acknowledge the impact on riders.

"There's going to be short‑term pain for a long‑term benefit for them," NJ Transit President and CEO Kris Kolluri said. Amtrak executive Laura Mason said the next four weeks "might not feel short," but the bridge is expected to last 100 years.

The work carries a price tag of about $2 billion and requires two major "cutovers." The first, designed to open the track out of New York City, is scheduled to run through March 15. A second disruption is expected in the fall when the remaining track is installed.

Mason said crews will work two shifts a day, seven days a week, with 70 to 90 workers per shift. Kolluri said the job requires decommissioning existing rail track while trains operate on nearby lines and rebuilding communication, catenary and signal systems.

With fewer trains running, revenue will drop. NJ Transit has already scheduled annual three percent rate hikes since 2024. Kolluri said reliability remains the focus and that stronger performance can support revenue over time. NJ Transit rail has not reached its monthly 95 percent on‑time goal since January 2023. Kolluri said more improvements are needed and noted the agency pays Amtrak more than $85 million a year for system maintenance.

Mason said Amtrak is prioritizing where work should happen and has pending grant requests for an upgraded catenary system and a new signaling system west of Newark.

NJ Transit is asking riders who can work from home to do so over the next month. Kolluri said he is confident in the plans, while Mason said snow and ice slowed some preparation but still expressed confidence. Kolluri said he will not compromise rider safety.

Commuters facing two major disruptions this year will expect the smoother service that has been promised once the bridge replacement is finished.