Was this bridge originally built as truss bridge? I grew up (from birth to age 14) in sight of that bridge. I have dim memories of its being closed during the late '40s for reconstruction. I seem to recall that before that time, it was a stone arch bridge as were so common in Montgomery County.
When the bridge was reopened it had a wooden deck. Each summer a crew of county employees would come out and spend about a week or so replacing damaged deck boards.
This bridge is in the heart of the Fetters Mill National Register Historic District, a village district in a wooded area of suburban Philadelphia. Every effort should be made to rehabilitate this bridge. Its traffic-calming one lane size is context sensitive to the village. Replacing it, as proposed, will increase traffic size and volume, introduce commuter traffic, and put the immediately adjacent c. 1749 Fetters Mill in jeopardy and ultimately destroy the village.
This bridge is in my former hometown and I used to hang out betwen here and the former Reading Railroad Station and still in use Post Office at Bryn Athyn.
Montgomery County (in which this bridge lies) is just outside Philadelphia City/County.