U.S. 95, Thorncreek Road to Moscow Project


The design process consists of selecting a preferred alternative in conjunction with the environmental process, the evaluation of design standards, and the preparation of a plans, specifications, and cost estimate (PS&E) package in conformance with these standards. The design process is outlined below.

The concept phase will begin at the same time as the environmental phase begins. The goal during the concept phase is to establish the purpose and need for the project, as well as design standards. Furthermore, possible alignment alternatives are evaluated and ranked based on environmental impacts, functional considerations and costs.

Once the concept is approved, the preliminary design phase begins. This phase consists of studies and information gathering that will be required for further environmental studies and final design. Such studies include geotechnical reports, hydrology/hydraulics studies and the evaluation of structural requirements (for bridges, box culverts and other structures).

Final design consists of preparing detailed plans for the proposed roadway and any proposed structures.

These plans, along with specifications (contract documents) and a construction cost estimate are then prepared for bidding purposes. The PS&E package preparation cannot begin until the environmental and right-of-way approvals have been obtained.

Winter 2018/2019 Update

The Idaho Transportation Department continues to move forward with plans for the U.S. 95, Thorncreek Road to Moscow Project.

The final eastern route (E2) for the highway was chosen after a multi-year environmental review process. The Federal Highway Administration issued a Record of Decision (ROD) for the project in 2016, giving ITD authority to begin final design and purchase land.

A legal motion was brought against FHWA and ITD in 2017 regarding the Environmental Impact Statement and Record of Decision. The U.S. District Court for Idaho ruled against the motion in favor of FHWA and ITD in August 2017.

Project opposition appealed that decision in January 2018. The U.S. Court of Appeals for the Ninth Circuit upheld the lower court’s decision on December 7, 2018.

ITD will continue right-of-way acquisition and submit a 404 permit application with the U.S. Army Corps of Engineers. After those two steps are completed, the project can be put out for construction bids. Work could begin as early as late summer 2019.

Please call Ken Helm at (208)799-5090 if you have any questions about the project.