The State has two alternative designs for the new bridge, but they are very similar with respect to how they affect South Nyack.
The new bridge will come ashore in South Nyack just to the north of the current bridge and merge into the highway at about the same place as the current bridge landing.
The limit of construction for the reconstructed highway in South Nyack is just west of the South Broadway overpass. In the current plan, no changes are proposed to Interchange 10. They do say, though, that Exit 10 could be used as a construction staging area.
The new design has a pedestrian and bicycle path, the roadway that will be much higher than the existing roadway, and the South Broadway overpass will be replaced. Entire or portions of nine properties including six homes will be taken by eminent domain.
The landing in South Nyack, new overpass design, and the properties to be taken can be viewed here (The drawings are also available at Village Hall.):
http://www.thenewtzb.com/deis/a2-short-span-option.pdf
http://www.thenewtzb.com/deis/a3-long-span-option.pdf
Shared-use path
The new Tappan Zee Bridge is designed to have a pedestrian and bike lane (aka “shared-use path”) on its north side. When it comes ashore in South Nyack, it runs along the north edge of the highway and ends at South Broadway. To accommodate the path, a slice of land is being taken from the Bradford Mews apartments and properties on Smith Avenue.
Thruway will be taller
The current highway is relatively flat as it heads east from South Broadway and onto the existing bridge. The causeway is flat and then rises steeply to the bridge’s center span. The plans for the new bridge have the highway rising gradually and evenly from South Broadway to the center span. This means the highway will be quite a bit higher than the current highway from South Broadway to River Road. (The “long-span option” bridge is quite a bit taller than the “short-span option” bridge.)
On the south side of the highway, the highway will be widened and a new retaining wall will be built. Along the south side, a 20′ sound barrier is proposed. Several homes on Ferris and Bight Lanes will have their river views cut off completely.
New South Broadway overpass
In order to transition the highway traffic from the existing bridge onto the new bridge, as the new landing is built the traffic will be temporarily shifted north and south. In order to shift the traffic, they say they need to make the highway wider from South Broadway to the river. In order to widen the highway, they say they have to replace the South Broadway overpass. Their design for the new overpass has them taking six homes and a public pocket park by eminent domain.
The current South Broadway overpass has a span of 148 feet and is held up in the middle by a pillar. (This is where the garage is for the truck that moves the TZB’s movable barrier.) The new overpass’ span across the highway is proposed to be 170 feet. Current Federal standards require the new overpass to have a clearance of 16.5 feet over the highway. Because of this, the new overpass will be taller than the current one and it’s much more difficult to design the overpass to meet grade on either side.
Also, because they will be shifting the traffic back and forth, they do not want a center pillar for the new overpass. Without a support below, the overpass is proposed to be supported from above with a truss, arch, or some other sort of superstructure. (This hasn’t been designed, yet.)
The new overpass is designed to be built and put into place next to the current overpass. This is so the current overpass can be kept open until the new one is ready. But it means the new design has more severe curves in it. It also means that two homes on the north side and one on the south side are taken. In addition, three more homes and the pocket park on the south side are taken to provide a construction staging area. The plan is to assemble the new overpass there and then lift it into place. Once the new overpass is in place the staging area would be freed up. While that land will be titled to the Thruway, they have hinted that they may be willing to eventually turn it over to the Village.