Yonkers, N.Y. Hudson River Bridge/Northern Metro Regional Bypass

 

The George Washington Bridge NEEDS alternative routes- the NYC Metro Area must have additional trans Hudson River crossings.  Northwards to the Tappan Zee Bridge, Yonkers is the best, for connecting with the existing east-west Cross County Parkway- a freeway reconstructed during the 1960s, 1970s and early 1980s that excludes trucks.

Yonkers, NY authorities appear to suggest the preferred site, marked by the naming of "Bridge Street" at the east west axis of Ludlow Streets, where it would land, with its approach eastwards into a hill by Route 9, where the highway would continue within tunnel, with connections to and from the north to the Cross County Parkway.

 

Extend that Yonkers, Ludlow Street axis to New Jersey, where it would land.  It would have connections with the Palisades Parkway.  And it must have a minimum of 6 lane mainline continuing west, as simply linking to the Palisades Parkway is problematic given the lack of a continuous traffic light free link to I-95.  Years ago, 1940s-1950s, the Yonkers, N.Y. - Alpine, New Jersey bridge was proposed to have an all new freeway continuing west, which was not built.  Instead, have a tunnel that arcs southward to follow the Northern RR, to connect with I-95/I-80.  

The I-80/I-95 to bridge link would be via tunnel, cut and cover along the Northern Line., and then curved towards facing Yonkers, with portal by the Palisades Parkway.  Curved portion would be bored to avoid surface disruption, emerging just past Montammy Golf Club, at the Palisades Parkway, to the bridge to Yonkers, N.Y., along Ludlow Street.  A minimum 6 travel lane facility could be either a single tunnel with two levels, or a pair of single or two level tunnels.  Existing 57 foot diameter TBMs require a pair of tunnels, each with a single 3 lane roadway, with only about 6 feet of shoulder space, or a double level 2 lane roadway with the 6 foot shoulder space.  Larger tunnels, 62, 67, 72 feet diameter would be preferable, particularly for line of sight within tunnels that are curved.

 

In Yonkers, this moled land approach tunnel might be a short segment, that emerges to cross atop the Saw Mill River Parkway, elevated over the valley, before entering a second tunnel further east as the topography rises, that extends further east to cross I-87, the Raceway Park parking lot, and the Bronx River into the City of Mt. Vernon, transitioning to cut and cover tunnel along 2nd Street.

 

Or instead it could be continuous with the west Yonkers segment descending to pass beneath Saw Mill River.

 

In Mt. Vernon, this cut and cover tunnel follows 2nd Street before turning south along the old N.Y., Westchester & Boston RR corridor, and continuing in the Bronx alongside that same RR's currently extant Dyre Avenue IRT line, to connect to and from the south with I-95 via an augmented 222nd Street exit, extending to the Throggs Neck Bridge Expressway, and providing a valuable new traffic corridor for handling potential emergency situation evacuation traffic.