KS Engineers, P.C. (KSE) provided comprehensive preliminary and final engineering design services for the replacement of Bergen County Bridge No. 020043A, carrying Old Tappan Road (County Route 116) over the Hackensack River in Bergen County, New Jersey. KSE’s multidisciplinary scope included bridge and roadway design, geotechnical engineering, hydraulic and scour analyses, utility engineering and relocation coordination, topographic survey and base mapping, right-of-way engineering, environmental permitting, and preparation of final contract documents. KSE also managed subconsultants responsible for wetland delineation, environmental permitting support, and historical and archaeological evaluations, providing seamless project coordination from concept development through final design.
Originally constructed in 1900 and partially reconstructed in 1972, the existing bridge had deteriorated to the point that it was classified as structurally deficient, scour critical, and functionally obsolete. The structure consisted of a prestressed concrete voided slab superstructure supported by aging concrete and stone masonry abutments that no longer met modern structural, hydraulic, or operational standards. Bergen County initiated the project to replace the aging crossing with a durable, low-maintenance structure while minimizing impacts to adjacent properties, utilities, environmentally sensitive areas, and the traveling public.
During preliminary engineering, KSE evaluated multiple replacement alternatives considering bridge type, structural materials, foundation systems, hydraulic performance, scour protection, traffic maintenance, utility conflicts, right-of-way impacts, environmental permitting requirements, constructability, and life-cycle costs. The alternatives analysis also examined options for staged construction versus temporary detours and evaluated roadway cross sections that balanced vehicle operations with enhanced pedestrian accommodations.
Following County approval of the preferred alternative, KSE advanced the project through final design for a jointless, 55-foot single-span prestressed concrete box beam bridge supported on semi-integral abutments. The jointless design significantly reduced long-term maintenance requirements while improving durability and structural performance. The project also included relocation of an existing gas main and telephone utility ducts onto the new bridge structure, eliminating future utility conflicts and simplifying long-term maintenance access.
Roadway improvements incorporated a wider sidewalk to enhance pedestrian safety and accessibility, while the bridge geometry and approach roadway were refined to improve overall traffic operations. Throughout the design process, KSE carefully balanced engineering, environmental, hydraulic, and community considerations to develop an economical solution that minimized construction impacts while extending the service life of this critical transportation asset.
The completed bridge provides Bergen County with a modern, resilient crossing that improves structural integrity, hydraulic performance, pedestrian safety, and long-term maintainability while preserving mobility along an important county roadway.
The project’s innovative design, technical excellence, and successful replacement of a critical county bridge were recognized with the American Council of Engineering Companies of New Jersey (ACEC NJ) Award for Engineering Excellence.
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