50th Ave. Roundabout and Pioneer St. Widening

The Pioneer St widening and 50th Ave roundabout project set out to improve the flow of traffic through the City of Ridgefield’s main thoroughfare. Over 20,000 sq ft of structural earth wall was installed in order to widen Pioneer St, construct multi-use paths on each side, and complete the extension of N. Pioneer Canyon to relieve traffic for the new businesses coming to Ridgefield. During this project, Costco opened a new location, and In-N-Out held a grand opening for their first store in Washington State. ACI and the City worked together to create traffic plans that could accommodate the influx of traffic due to these major openings while minimizing the impact to construction efforts. In addition to the road improvements, there were also improvements to the City’s underground infrastructure. This project included a joint utility trench, a gravity sewer system, a water main, a storm system, and a bioretention facility. The project also contained 5 fish passage culverts and a new channel to improve stream conditions for the wildlife inhabiting the tributaries running through the site. The biggest culvert spans across Pioneer St at 178 ft long and 18 ft wide. Within the new roundabout, artwork created by Ridgefield High School’s welding class was erected. The 20 ft tall centerpiece showcases the collaboration between the community, owner, and project team that went into making this project successful. The project was completed in late 2025 and has resulted in a great working relationship with the City of Ridgefield.