In 2001, the Pennsylvania Department of Transportation and its contractors published an assessment of approximately 12,000 bridges for potential eligibility for the National Register of Historic Places. The study aimed at creating a Bridge Management Plan to identify which bridges could and should be preserved. Based on this assessment, Pennsylvania had 333 historically significant metal truss bridges: bridges which were either listed on the National Register of Historic Places or eligible for it. Since then, many of these historic structures have fallen into disrepair and have been demolished and replaced. Today, 40% of the bridges intended to be preserved have been demolished statewide.
This map shows the current status of these historic structures and identifies which counties and PennDOT engineering districts have been most and least successful at preservation. Initially, the map shows the percent of historically significant metal truss bridges from 2001 that have been demolished in each county. Zoom in to see the status of each bridge.
Note: The current status of each bridge is based on Google Maps aerial imagery and Street View, Bridgehunter, HistoricBridges.org, and local knowledge.