Howellville Road Bridge Replacement

Tredyffrin Township, Chester County, Pennsylvania

Built in 1879, the original Howellville Road Bridge was a historic structure within Tredyffrin Township, a community of nearly 30,000 in eastern Chester County, Pennsylvania. After 140 years of use, the single span wrought-iron Warren truss bridge had a "poor" condition rating in accordance with the Federal Highway Administration's (FHWA) National Bridge Inspection Standards. Officials from Tredyffrin Township decided to move forward with the construction of a new bridge that would combine the historic aesthetics of a truss bridge with modern safety features.

Michael Baker International led the design of the new bridge, which included the replacement of the structure, with a truss on alignment, including new abutments and wider bridge crossing to accommodate appropriate shoulders for traffic and pedestrians on the two-lane structure. The firm also coordinated field surveys and performed a bridge rehabilitation feasibility study, including background research, definition of the project's area of potential effects and identification of historic properties. Using the bridge preservation assessment, Michael Baker prepared an analysis of alternatives report and a determination of effects report to document alternatives developed to meet the project purpose and need and measures taken to avoid, minimize or mitigate effects to historic properties. On behalf of Tredyffrin Township, Michael Baker consulted with the Pennsylvania State Historic Preservation Office (PA SHPO) pursuant to the State History Code.

Michael Baker prepared roadway plans, drainage, signing, pavement marking, traffic control and erosion and sediment control, provided structure borings and environmental soil testing, prepared a geotechnical structure foundation report and developed plans for the recommended structure.

Additionally, the bridge was located over a Norfolk Southern Railway track, which required close coordination with the railway to limit disruption to their service during construction.

The new structure opened to traffic on July 1, 2021. Michael Baker met the township’s needs for a new bridge with historic aesthetics and safety features that would minimize maintenance for years to come. Despite the delays caused by COVID-19, the project was completed before the start of the 2021 school year – an important deadline for the township.

The old historic wrought-iron truss bridge, which is eligible to be listed on the National Register of Historic Places, was relocated to Tioga County, where it will be repurposed and reused for a future pedestrian trail project.