The Towns of Dennis, Yarmouth, and Barnstable selected VHB to provide design services for the eight-mile extension of the multi-use Cape Cod Rail Trail (CCRT) and to design four bridges for the project—at Route 134 in Dennis, at Station Avenue in Yarmouth, at the Bass River crossing, and at Willow Street in Yarmouth. Construction for Phases 1 and 2 were completed in the fall of 2017 and 2018, respectively, with construction of Phase 3 beginning in early 2025.
The CCRT extension crosses the Bass River at the site of the most restrictive hydraulic opening on the tidal river, which features restricted tidal exchange and boat navigation hazards. VHB led the hydraulic analysis to evaluate four alternative pedestrian bridge designs, developing an unsteady-state model using HEC-RAS software to simulate tidal flushing and identify hydraulically viable abutment alternatives. VHB used the model to evaluate alternative larger bridge openings, assessing benefits to tidal exchange and navigation and potential impacts to flood levels during extreme events. The new pedestrian bridge increases tidal flushing of the river system and improves navigation.
