Untitled Document

Transportation Planning Award
Idaho 75, Timmerman to Ketchum
Environmental Impact Statement (EIS)

Submittal: Parsons Brinkerhoff
Contributing partner: ITD, District 4
Key personnel: Brent Inghram (Federal Highway Administration), Chuck Carnohan (ITD, D-4), Chuck Green (Parsons-Brinkerhoff), John Thomas (Parsons-Brinkerhoff), Jan Striefel (Landmark Design); and Mark Vlasic (Landmark Design)

Project details: Parsons Brinkerhoff initiated the project in 2000, preparing an EIS for 27 miles of highway in Blaine County between U.S. 20 (Timmerman Junction) and the resort area of Ketchum/Sun Valley. A Record of Decision (ROD) was issued in August 2008 after a much-coordinated effort that used a variety of transportation modeling tools to properly forecast future travel demands and assist in garnering project support.

Since no travel demand model existed for the project area, extensive data was collected through an intercept survey of Idaho 57; typical gathering of traffic counts, travel times and highway speeds; and a Stated Preference Survey to determine user choices if transit options were made available. All data was used to calibrate the models and analyze performance measures.

The relationship of land use to transportation was a key concern to Wood River Valley Stakeholders. To ensure the relationship was reflected in the development and evaluation of alternatives, assistance was solicited from Blaine county planners, local developers, real estate agents and policymakers.

Working with those groups and other was fundamental to obtaining acceptance and support for the proposed Idaho 75 improvements.