TARRYTOWN, N.Y. (CBSNewYork) — It’s been years and billions of dollars in the making, but the new Mario M. Cuomo Bridge is now partially open to traffic.

Some of the first drivers to ever cross the bridge drove down the Rockland bound lanes just after 1:30 a.m. Saturday.

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“I am so excited, it is such a beautiful bridge,” Rockland County resident Faye Stein told CBS2. “It’s just breathtaking.”

Rockland-Bound Traffic To Switch To New Gov. Mario Cuomo Bridge

People were thrilled to wake up Saturday to a brand new bridge that’s now open to westbound drivers.

“We just crossed through,” Rockland resident Andre Vital told CBS2’s Reena Roy. “It’s really nice. We loved it!”

The $4 billion trans-Hudson construction has been in the works for four years.

Governor Andrew Cuomo celebrated the replacement to the Tappan Zee Bridge at a ribbon cutting ceremony Thursday, touting the new bridge named after his father as both on time and on budget.

“We are leaving an old, dangerous, traumatizing bridge and it’s replaced by a new, safer, smarter structure,” the governor said.

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The new bridge dedicated to former Governor Cuomo has two twin spans, one of them currently handling four lanes of drivers heading from Westchester to Rockland County.

Drivers are strongly encouraged to abide by the 45 mile per hour speed limit as construction continues.

The other span, for drivers heading from Rockland to Westchester County, is not yet open. Until the fall, drivers heading eastbound and southbound will have to stick with the old bridge.

“Mario Cuomo would be proud of what we have done,” the current governor said of his late father.

The bridge’s new name is thanks to a last minute legislative push. The old name honored former Governor Malcolm Wilson, plus the Native American Tappan tribe and early Dutch settlers.

Some residents are unsure the new name will stick.

“They should’ve kept the old name,” Vital said. “The Tappan Zee Bridge.”

“I know everyone’s heating up on social media about the Mario Cuomo Bridge, but I think it will still be referenced as the T-Z Bridge,” Stein said.

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Officials say 140,000 vehicles are expected to use the new span each day. It costs $5 to cross, but a toll freeze is expected to end in three years.