Sens. Chuck Schumer and Kirsten Gillibrand, Gov. Kathy Hochul and U.S. Transportation Secretary Pete Buttigieg were among the elected officials on hand Friday to mark the start of work on the Gateway tunnel project, which will build a second rail tunnel under the Hudson River.

Construction began Friday on a final section of concrete casing that will preserve the ability to construct a new tunnel between New Jersey and Penn Station. The first two sections of the casing were repaired several years ago.

Schumer also announced Friday the allocation of an additional $3.8 billion in federal funding for the project, which is set to be the nation's largest public works project.

The announcement came on the heels of $6.88 billion Schumer unveiled in July, the largest such grant to a mass transit project in U.S. history.

Schumer said the newly secured $3.8 billion from the Federal Railroad Administration will be allocated toward critical elements such as track, signals and systems, while the July FTA funds will support the concrete core and shell of the Gateway Tunnel.

"This is huge for mass transit and transportation across New York," Schumer said at a news conference, calling the allocation a "major, major milestone" for the project. "With these new dollars, Gateway's future is assured. All systems go. There is no turning back."

The new rail tunnel under the river will serve Amtrak and New Jersey Transit. As part of the project, workers will also repair an existing tunnel damaged during Hurricane Sandy.

The existing tunnel is the only passenger rail tunnel between New Jersey and New York. More than 200,000 passenger trips are made on trains through it each weekday, according to the Biden administration.

Schumer said the project will also provide a large boost to the economy, predicting the creation of 72,000 jobs and $19 billion in economic activity.

The new tunnel will provide a vital artery in the northeast for rail traffic, where travel demand could rise as much as 32% more than pre-pandemic levels by the time the project is completed, according to estimates by the Regional Plan Association, a century-old nonprofit dedicated to the development of the New Jersey-New York-Connecticut region.

"For 30 years, Americans travelers, businesses, workers have been hoping for this day. But years of inaction, excuses, delays and the infighting are finally over," Gov. Kathy Hochul said at the news conference.

"We're now heralding in a new era of working not against each other, but working together to accomplish great things," she added.

The Obama administration prioritized the Gateway Program as one of the most important infrastructure projects in the country, but it was stalled during the tenure of former President Donald Trump, who urged Congress to slash its funding.

After his election in 2020, President Joe Biden prioritized funding for the project again in his $1 trillion infrastructure bill. Now, Schumer has declared the project has moved past the "dark days."