West Washington Avenue Bridge Replacement over Pascack Brook

What Was the Challenge?

The existing West Washington Avenue Bridge, built in 1930, exhibited significant deterioration in both its superstructure and substructures, warranting full replacement. Beyond structural issues, the roadway carried several non-standard geometric features, including steep vertical grades, tight horizontal curves, and limited stopping sight distance that posed safety concerns. The undersized hydraulic opening and misaligned channel contributed to roadway embankment scour and localized flooding along Pascack Brook. Rockland County needed a modern crossing that improved safety, addressed hydraulic deficiencies, and corrected long-standing roadway alignment issues.

How did Barton & Loguidice Provide a Solution?

B&L provided preliminary and final design services, along with construction support for design-related reviews and contractor inquiries. The replacement structure is an 80-foot single-span bridge consisting of metalized steel girders with a composite concrete deck on integral abutments, constructed along an improved upstream horizontal and vertical alignment. The stream channel and hydraulic improvements included realignment and restoration of approximately 500 linear feet of Pascack Brook, where B&L incorporated natural channel design elements, including rock riffles, cross vanes, and J-hooks, to reduce scour, control velocities, and improve overall stream stability.

To integrate the new bridge and improve roadway geometry, the project also included 1,100 linear feet of full-depth roadway reconstruction to improve sight distance, vertical grades and overall motorist safety. Hydraulic performance was significantly improved to provide two feet of freeboard during the 50-year storm and ensure passage of the 100-year event beneath the structure. The project required extensive utility coordination to accommodate suspended water, sewer, and gas lines on the new bridge, as well as environmental coordination to minimize impacts resulting from the roadway relocation and stream improvements. Coordination with NYSDOT and SHPO addressed minimal impacts to adjacent parkland.

Why Was This Project a Success?

The new bridge design resolves structural, hydraulic, and geometric deficiencies that had long affected safety and performance along West Washington Avenue. By improving hydraulics, realigning the stream, and modernizing roadway geometry, the project reduces flood risk, minimizes scour, and enhances driver safety. Thoughtful environmental coordination and utility planning ensured that the project progressed smoothly despite complex site constraints. The result will be a safe, resilient, and sustainable crossing that better serves residents and supports long-term corridor reliability.