The existing Section 251 structure is a multi-span hybrid steel/concrete bridge carrying Route 435 over the Delaware Lackawanna (D&L) Railroad and an Unnamed Tributary to Roaring Brook. In its existing condition, the bridge is structurally deficient with deteriorated substructure concrete and will be replaced with a multi-span steel bridge. In addition to the mainline bridge replacement, two other culvert replacements are included with the project. Existing pipes conveying an Unnamed Tributary to Roaring Brook under Front Street will be replaced with a reinforced concrete box culvert. Immediately downstream, two existing culverts under the D&L Railroad and an Access Road will be replaced with a single reinforced concrete box culvert. An Access Road will be realigned as part of the culvert replacement. 

The existing Section 253 structure is a single span concrete arch culvert that carries Route 435 over Roaring Brook about ¼ mile to the north of the Section 251 bridge. The Section 253 culvert is in poor condition and will be replaced with a single span prestressed concrete bridge. 

Roadway improvements associated with the project include reconstruction of the Front St and Gardner Road intersections on the southern portion of the site to improve safety and driver expectation. Full depth pavement reconstruction will be required along Route 435 for the bridge replacements, at the reconstructed intersections, and along Front Street for the culvert replacement. New guiderail and pavement markings will be provided throughout the project limits. 

As part of the project’s traffic control plan, a temporary bridge/roadway with at-grade railroad crossing of the D&L tracks will be used to connect Route 435 with Front Street. Due to the grade difference between the tracks and existing roadway, Front Street will require temporary profile and alignment modifications to complete the at-grade railroad crossing and intersection. This will be integrated into a temporary run-a-round that will maintain traffic on-site and avoid lengthy detours during full width replacement of the mainline structures. In conjunction with this traffic control approach, a connector between the end of GC Smith Street and the temporary road will aid in maintaining traffic during planned work on the GC Smith Street Bridge over Roaring Brook (this bridge is not part of the Route 435 project). A temporary detour of Front Street is required for the installation and removal of the temporary facility, as well as for the construction of the new box culvert. After the construction project is complete, existing grades will be restored along the temporary roadway. 

Drainage will be installed around the new bridges and intersections as required to meet current design requirements. In addition, improvements to an existing drainage swale located in the northeast portion of the site will reduce sedimentation currently seen at its outfall to Roaring Brook. The outfall penetrates an existing reinforced concrete retaining wall on the north side of the brook at the northeast wing of the Section 253 culvert. The retaining wall currently exhibits cracking in the portion of the wall near the outfall and is expected to be removed entirely and the streambank restored in this area. Although the channel improvement will extend up the slope onto the Lackawanna County Trail property, the temporary construction impact will be less than 6 months.