NYSTA Replacement of Tappan Zee Bridge
westchester & rockland counties, ny
AI assisted the design-build team on the replacement of the Tappan Zee Bridge between Westchester and Rockland Counties in New York. The team was comprised of the owner, New York State Thruway Authority (NYSTA); the design-builder, Tappan Zee Constructors, LLC; and the lead designer, HDR. The new NY Bridge will replace the existing Tappan Zee Bridge with twin three-mile long structures, each with 1,200-foot cable-stayed main spans and 350-foot steel girder approach spans. The new bridge provides eight general traffic lanes, emergency lanes, extra-wide shoulders ready for express bus service, a dedicated bicycle and pedestrian path on the northern span, and scenic overlooks. The westbound bridge is scheduled to open in 2016 and the eastbound bridge completed by 2018. The new bridge was designed to last 100 years without any major structural maintenance.
AI's involvement with the project included the design of the following elements:
- Anchors to fasten light standards to the bridge deck, medians and noise barrier walls.
- Equipment platforms at the catwalk level to support the power transmission systems of the bridge, including removable platforms to house the power transformers.
- Removable vehicle barriers at emergency turnaround locations.
- Railings and lanyard tie-off points for the protection of maintenance personnel at the bridge piers.
AI also designed other proposed elements such as:
- Pedestrian fences throughout the bridges and landings. The length of inclined fence was 64,000 ft. and the straight length was 16,000 ft. Work included fences at the fascia and median of each bridge, as well as between the eastbound lanes and the shared use path, the fence gates at the shared use path and the transitions at belvederes and expansion joints.
- Posts and anchorages to support emergency phones.
2013 - 2014
- New design to last 100 years without major structural maintenance