Project Info:

Location: Yakima County, Washington

Role: Prime

Owner: Yakima County

Client: Yakima County

Construction Cost: $112,682,000


  • Corridor Study
  • Interchange Modification/Justification Report Development
  • Alternatives Development and Analysis
  • Environmental Study
  • Highway/Roadway Design
  • Interchange Design
  • Structural Design
  • Intersection Analysis/Design
  • Retaining Wall Design
  • Landscaping and Aesthetics Coordination
  • Trail Planning/Design
  • Stormwater/Pavement Drainage Design
  • Hydraulic Modeling
  • Cost Estimate Development
  • Traffic Impact Analysis/Study
  • Travel Demand Modeling/Forecasting
  • Capacity Analysis
  • Public Meeting Coordination
  • Stakeholder Facilitation


A proposed roadway, the East-West Corridor would connect Terrace Heights and Yakima, relieving congestion on Yakima Avenue and other major arterials in this growing area. The new route would begin at North 1st Street in Yakima, connect to and continue over I-82, cross the Yakima River, and end at Butterfield Road—a distance of nearly two miles. Yakima’s H Street would also be reconstructed from North 1st Avenue to the Cascade Mill District. The proposed corridor would provide new public transit routes and facilities for mutlimodal travel, improve emergency response times, and encourage development in the Cascade Mill District. Lochner was responsible for the corridor study, preliminary design, and the interchange justification report for connecting to I-82.
As part of the corridor study, Lochner developed a series of alternative design concepts for evaluation, including assessing issues of environmental impact, right of way acquisition, constructability, and cost. The East-West Corridor mainline was designed to be a boulevard-style, complete streets, four-lane arterial with landscaped medians, entrance-way enhancements for vehicles entering Yakima, and a shared-use path adjacent to the roadway. Lochner developed concepts for a crossing over I-82 and the new I-82 interchange as well as developed an interchange justification report that reviewed the need for ramp improvements at the I-82/Yakima Avenue interchange. Lochner also provided preliminary design solutions.
The major focus of the corridor study was two new bridges that will cross the Yakima River—one for the roadway and one for cyclists and pedestrians. As the river provides habitat for two species of endangered fish, Lochner evaluated several bridge design alternatives, up to 850 feet in length, that incorporated design and construction strategies to minimize or mitigate temporary and permanent impacts to this habitat. The new road would cross a disused municipal waste site, and Lochner’s study addressed alternative strategies to manage the waste (which could not be directly built on) such as removal, consolidation, and construction of a bridge over the entire site.
Lochner’s chosen proposed alignment resolved multiple environmental challenges, including avoidance of potentially sensitive historic tribal lands, crossing a major irrigation canal, coinciding the roadway alignment with a new Corps of Engineers approved levee, crossing the Yakima River and I-82, then passing through an abandoned mill site and addressing the environmental justice issues of a street improvement project in a low-income neighborhood. The proposed alignment also included an innovative collector-distributor system parallel to I-82 to reduce interstate access points from five to four, a concept approved by the Federal Highway Administration, and included a nearly two-mile expansion of the regional multi-purpose path, the Yakima Greenway.