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US-20 Ashton to SH-87 JCT

The Idaho Transportation Department (ITD) is conducting planning study to look at improvements to US-20 corridor between Ashton and the ID-87 Junction.

Increasing traffic is causing congestion and crashes. Improvements are needed to maintain a safe roadway and reliable connection to adjacent communities, Yellowstone National Park, and the region.

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US-20 Ashton to State Highway 87 Study

The study will help weigh the benefits and impacts of proposed transportation system improvements to the environment, community, and economy during the transportation planning process. The purpose is to coordinate statewide and transportation planning with the National Environmental Policy Act (NEPA) process to streamline project delivery.

The study process will identify and analyze US-20 between Ashton and the SH-87 Junction and will look at ways to address the following deficiencies:

      • Travel time and delays
      • Congestion
      • Safety – specifically, with the goal of reducing the number and severity of crashes
      • Outdated design standards

The study has identified concept alternatives that could be implemented as funding becomes available. Using public input, and data from the traffic and other scientific studies, the project team will develop concept level alternatives for the corridor.

      • Alternatives may include upgrades/changes to the current alignment of the highway
      • Alternatives will consider both on and off alignment solutions, additional lanes, access control, and spot safety improvements

Traffic studies will be updated often throughout the process to reflect the vibrant and changing nature of the population traveling the highway.

The study is screening alternatives based on the following environmental criteria:

  •  Visual
  • Agricultural and Forest Resources
  • Air Quality
  • Biological Resources
  • Cultural Resources
  • Geology and Soils
  • Hazards and Hazardous Materials
  • Hydrology and Water Quality
  • Land use and Transportation Planning
  • Noise
  • Social and Economics

Read more about the PEL process here
Nov. 21, 2021

Save the Date - Alternatives Workshops

Join us for Alternatives Workshops

Dec. 1, 2021

RSVP for workshops and view the Public Meeting Summary

RSVP to attend Alternatives Workshops and view the Public Meeting Summary

Dec. 13, 2021

Alternatives Workshop Information

Workshops results to share. View presentation materials, maps and the virtual session recording.

May. 25-26, 2022

Public Meeting(s) #3

The purpose of these meetings was to share the alternatives developed from previous public workshops and the results of the screening committee.

To be determined

Public Meeting(s) #4

These meetings have been postponed. ITD will schedule another round of public meetings within a few months and will notify people through mailings, emails, posters and social media. The project team is postponing the September meetings to take a closer look at potential alternatives for US-20.


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Project Schedule

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US-20 Ashton to SH-87 Project Schedule

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