Mill Road Bridge

Information and Findings From Pennsylvania's Historic Bridge Inventory

Discussion of Bridge

The one-span, 30'-long stone arch bridge, built 1912, has voussoirs with keystone, fieldstone spandrel walls, and parapets with slate coping. It is supported on stone abutments. The intrados is pargetted and the bridge has grapevine repointing. It is a short and undistinguished example of a bridge type that is common from the first two decades of the 20th century in Chester County. The county-built traditional stone arch bridges were favored by the county engineer, and at least 19 similar bridges from 1908 to 1919 have been identified. Stone arch bridges have been in use in Pennsylvania since the late 17th century, and over 350 examples have been identified statewide, with more than two-thirds dating to before 1900. Early 20th century examples in Chester County are considered individually significant in the local context only when they are complete and large or particularly well detailed. This example is not historically or technologically distinguished within its population or by its setting and context.

Discussion of Surrounding Area

The bridge carries 1 lane of a 2 lane road over a stream in an area of suburban commercial development north of US 202. South of the bridge are late-20th-century office parks. At the bridge's northwest quadrant is a parking lot associated with a township park with playgrounds and recreational fields. The setting does not have historic district potential.

Bridge Considered Historic By Survey: No, Later Reevaluated as Individually Eligible, Per Management Plan

Information and Findings From Pennsylvania's Stone Arch Bridge Management Plan

Discussion of Bridge

The bridge is not a strong candidate for long-term preservation. It ranks in the lower half of all stone arch bridges under study in this plan. The bridge is individually eligible for listing in the National Register of Historic Places and is part of a greenway. The condition code is high. However, the bridge has not received public support. The waterway is only marginally adequate. Waterway adequacy is a function of the size of the arch barrel, which is also the main structural element. Widening the barrel requires the bridge to be rebuilt. The bridge's transportation code is low; it is not able to adequately handle its current traffic volume, the bridge is located on a curve, and it has poor sight distances. Moreover, it is located in an area of moderate development, where future traffic can be expected to increase somewhat, exacerbating the traffic problem. The cost to rehabilitate the bridge is moderate, making it moderately expensive to rehabilitate its historic form and fabric.

Ratings

The Tredyffrin, Mill Road Bridge is owned by Chester County and is ranked 67th.
Condition Code = 59 - high
Transportation Code = 42 - low
Waterway Adequacy Code = 46 - moderate
Cost to Rehabilitate or Replace Code = 54 - moderate
Anticipated Development Code = 48 - moderate
Recreational, Historical, and Cultural Values Code = 62 - very high
Public Input Code = 35 - very low

Recommendation: Not a strong candidate for long-term preservation.