GP-11
Montgomery County, PA
S.R. 1033, Section 45M over Molasses Creek
Alternative Analysis
Four alternatives were evaluated to address the structural and operational deficiencies of the existing Kutztown Road Bridge and the environmental impacts of the replacement structure.
Alternative 1 , the no-build alternative, would not address the deficiencies of the existing stone arch structure deficiencies, such as deteriorated pointing, spreading of the spandrel walls, and deficient drainage of the fill between the spandrel walls. In addition, the existing structure is in a perched position with respect to the approaching roadway, causing vehicles to “bottom out” after passing over the short structure. Presently, it can only accommodate one lane of traffic, creating safety concerns for opposing vehicles as they proceed across the structure. The benefits associated with this alternative would be the absence of impacts to Molasses Creek.
Due to the above considerations, this alternative was eliminated, as it does not meet the project need.
Alternative 2 would involve rehabilitation of the existing bridge. The rehabilitation of the existing structure would require extensive repairs, most likely to the point of only using the existing stones of the structure for decorative purposes. The stone barrel of the bridge would require either a reinforced concrete sub-barrel constructed above the existing stone barrel or extensive reinforcing with special tie bars. These treatments would also be required for the spandrel walls.
This present structure is placed perpendicular to the roadway. Molasses Creek crosses under the bridge at an extreme skew, causing severe scour at the base of the arch and wing walls.
This scour has occurred over many years because the stream cannot flow under the bridge along its natural path. Repair of the existing structure would cost more than complete replacement of the structure, and the position of the bridge relative to the stream would remain unfavorable with this alternative. The traffic issues created by the perched roadway and single travel lane would not be resolved. Township officials and residents have agreed in two separate formal meetings that the stone arch bridge does not contribute to the view of the surrounding area.
Due to the above considerations, this alternative was eliminated. The rehabilitation alternative does not meet the project need.
Alternatives 3 and 4 involve the replacement of the existing bridge with a culvert and a cast-inplace rigid frame, respectively. Both alternatives would eliminate the existing deteriorated bridge, increase transportation effectiveness, increase the hydraulic opening, and improve safety concerns. The alternatives were compared based on the following:
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Economics - Replacing the existing bridge with a cast-in-place rigid frame bridge that spans the stream would be more costly and time consuming than a single cell reinforced concrete box culvert. It does, however, eliminate the need to divert the stream during construction. The added costs associated with stream diversion may increase the total cost of the single cell reinforced concrete box culvert to exceed that of the cast-in-place rigid frame bridge.
Foundation costs are always reduced with a single cell reinforced concrete box culvert (more so if the existing soil conditions are poor) because the weight of the bridge is spread out over a large area. Preliminary investigations, however, indicate that soil conditions at this location are good; therefore, the foundation costs of a cast-in-place rigid frame bridge should be significantly reduced. In addition, the use of a cast-in-place rigid frame bridge for this
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S.R. 1033 Section 45M Kutztown Road
Upper Hanover Township, Montgomery County, PA

particular location allows the use of a General Permit (GP-11), reducing the administrative costs of obtaining a permit for construction. A single cell reinforced concrete box culvert would require a Joint Permit, leading to more administrative costs to obtain approval.
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Temporary Impacts - The single cell reinforced concrete box culvert and cast-in-place rigid frame bridge would have similar temporary impacts. The time required for construction of the cast-in-place rigid frame structure may be slightly longer than the culvert, but the time associated with obtaining the Joint Permit Application offsets the impact.
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Right-of-Way Impacts - The single cell reinforced concrete box culvert and cast-in-place rigid frame bridge would have similar Right-of-Way impacts. Since the existing stone masonry bridge is perched, the roadway profile must be raised for both alternatives in order to pass the required 10-year storm, resulting in an increased required right-of-way acquisition.
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Permanent Stream Bed Impacts - The cast-in-place rigid frame bridge option would require fewer stream bed impacts than the single cell reinforced concrete box culvert. The box culvert would have a paved bottom, while the bridge would require rip-rap scour protection at the abutments. Although alternative 3, single cell reinforced concrete box culvert, will have baffles for fish passage and be depressed 1.0 foot to allow for natural streambed material to deposit in the structure the entire stream bed must be disturbed in order to place the box culvert.
In consideration of the previously discussed factors, Alternative 4, the cast-in-place rigid frame, was retained. The construction of a new cast-in-place rigid frame meets the project needs and is the preferred alternative.
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S.R. 1033 Section 45M Kutztown Road
Upper Hanover Township, Montgomery County, PA