Cate Street Bridge
Preparatory to active work on the Route 1 Bypass-Coakley Intersection Project, the City needs to replace the bridge on Cate Street which will become a more regularly traveled route.
The 2018 Portsmouth Citywide Bridge Evaluation (pages 11-13) determined that the Cate Street Bridge is beyond its 50-year design life, cannot handle heavy truck volumes and needs to be replaced. Residents have asked for the bridge to remain open if the median on Route 1 Bypass is extended past Cottage Street to ensure emergency vehicle access to Portsmouth Hospital from the neighborhood.
Background:
The existing bridge was constructed in 1940 and is comprised of painted steel I-beams and concrete deck. The total length of the bridge is 37’ and the clear span is 30’. The overall width of the bridge is 28’ and carries two lanes of traffic on a 20’ wide paved roadway. There is a 4’ sidewalk on the east side of the bridge. The bridge is currently load posted at a 3-ton weight limit; signs identifying the load restriction are installed in both approaches. An insulated utility pipe is installed on the exterior face of the upstream exterior girder, assumed to be a water main based on the presence of a fire hydrant on the same side of the road.
According to the NHDOT Bridge Inspection Report, the condition rating of the deck is a 2, or ‘critical’. The condition rating of the superstructure is a 5 or ‘fair’ and the substructure is a 6 or ‘satisfactory’. The bridge rail, transition rail, approach rail, and rail terminations are substandard. The bridge has an AASHTO sufficiency rating of 26% and is on the NHDOT Municipal Bridge Redlist.
Hoyle, Tanner performed a hands-on field inspection in January 2017 as part of a separate project completed for the City. The inspection was initiated after an approximately 3’ diameter hole developed in the concrete bridge deck that was discovered during a biennial NHDOT inspection. Results of Hoyle, Tanner’s structural inspection, as well as a summary of the load rating analysis and recommendations for repair of the deck, were summarized the in a Bridge Assessment letter dated April 3, 2017. The City immediately load posted the bridge and completed an emergency repair project that included installation of a steel plate over the hole in the bridge deck. The repair was considered a short-term solution, implemented with the understanding that a more extensive rehabilitation, replacement, or removal project would be necessary within the next several years to address the remaining deficiencies
The City applied to have a rehabilitation project for this bridge added to the NHDOT Municipal State Aid Bridge (SAB) program in September 2000. NHDOT processed this application and provided the City with a project cost estimate for SAB funding., but new projects are not currently being added to the SAB program. NHDOT has not identified when new projects will be added, or which Fiscal Year they will be added to for construction funding.
In August 2025, the City Council authorized bonding the replacement project rather than risking failure while awaiting NHDOT state funding and to support the match required for the NHDOT Local Project Administrator (LPA) and Federal funding secured for this project and is in the design consultant selection stage. Construction is estimated in 2028-2029.
Project Manager:
Tyler Reese, Project Manager – Engineering, Department of Public Works
603-766-3144
tcreese@portsmouthnh.gov
Contractor: