RS&H served as prime design consultant for the SR 105 (Heckscher Drive) bridge replacement over Sisters Creek. The existing bascule bridge was replaced with a new 3,300-foot, high-level fixed span structure. RS&H provided final roadway and bridge plans for the project. The project greatly improved safety and mobility by adding full-width shoulders, sidewalks, and local access connections.
This section of Heckscher Drive traverses a historical archaeological site and salt marsh wetlands. The Archer Western/RS&H team developed an Alternative Technical Concept that reduced impacts to high quality saltmarsh wetlands while minimizing construction activities in the vicinity of an archaeologically significant shell-midden area. Extending the bridge length on the east side of the project also avoided the extensive soil remediation that would have been required to construct a four-sided MSE wall (soil plug).