As a former Hackensack resident, I'll tell you what is commonly believed, which may or may not be correct. My understanding is that Washington retreated from New Bridge Landing down Main Street, and his army camped all along what is now Main Street from Passaic Street to the Green (site of current courthouse). And then the next day, the primary bulk of the army retreated west on Essex Street, and then south on Polifly Road, before zig-zagging through Hasbrouck Heights and downtown Lodi on the way to what is now the City of Passaic.
There are "retreat" signs on Polifly Road. I've also seen them on Passaic Street, and it is certainly possible that a portion of the army went west on Passaic Street into Maywood, enroute to downtown Lodi.
There were very few east-west roads in Hackensack at the time, with Essex Street and Passaic Street being the primary. Large areas of Hackensack were farmland, with perhaps some swamplands along the river and what is now central Hackensack, and pasturelands and woodlands on the hill in the west part of the city. I know that the bend of Essex Street in Hackensack was a STRATEGIC SPOT because it was a dry neck of land connecting the village of Hackensack to the hill. That is why the Native Americans had a trail there, which then became Essex Street. There were impassable swamps to the north (Newman Street) and south (South Newman Street), and there were no westbound roads south of Essex Street for many miles, perhaps all the way to Newark Bay. I'd have to check an old map to verify.
I can see why General Washington chose to retreat out of the old village of Hackensack, and not risk getting his army encircled and trapped there. Had the British been able to cross at New Bridge Landing quicker, they could have easily marched through the Fairmount area of Hackensack and onto the Summit Ave ridge, and then approached the old Village of Hackensack from the WEST, along Essex and Passaic Street. That would have completely trapped General Washington and ended the Revolution.
Yes, New Bridge Landing is the bridge that saved the nation, because the American forces dismantled it once they crossed and retreated to the Village of Hackensack.