SE 4th Street

Ardurra transformed an aging two-lane rural roadway into a modern three-lane arterial designed to serve Sammamish's new Town Center. The corridor now accommodates vehicles, bicycles, and pedestrians, creating a safer and more connected community. The team collaborated closely with residents and the City Council, using VISSIM microsimulation to model traffic performance and inform decisions. The final design introduced four new roundabouts, improved an existing signalized intersection, and retained a stop-controlled intersection. Extensive utility upgrades included underground power and communications, a new sewer main, and an upsized water main to support future growth. The team coordinated with private developers to align public improvements with concurrent redevelopment. During construction, the team managed complex challenges, including utility conflicts, severe weather, and a labor strike, delivering the project on schedule with no major delays.

Key Highlights:

• Converted rural two-lane road into multimodal three-lane arterial with four new roundabouts supporting Sammamish's Town Center vision
• Applied VISSIM micro-simulation to model traffic performance and guide design decisions with stakeholders
• Delivered critical utility upgrades, including underground power, new sewer main, and upsized water main, to enable long-term growth
• Maintained schedule despite record snowfall, labor strike, and evolving site conditions through proactive construction management

The project provided Sammamish with modern multimodal infrastructure that enhanced safety, connectivity, and capacity to support the new Town Center while coordinating with concurrent private development and overcoming significant construction challenges.