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I-5 Tumwater to Mounts Road Corridor Planning and Environmental Linkages Study

Planning study news

In 2018, the Washington State Legislature funded a corridor planning study of Interstate 5 between SR 121 in Tumwater (Exit 99) and Mounts Road near DuPont (Exit 116) to develop mid- and long-term strategies for improving the region's transportation system. The study strategies that were developed have expanded into the Planning and Environmental Linkages Study.

Spring 2020 - Fall 2021
In progress


The "Planning and Environmental Linkages" (PEL) study will build upon the goals and strategies outlined in the original 2018 corridor study. This PEL study represents a collaborative and integrated approach to transportation decision-making that:

  1. Considers environmental, community, and economic goals early in the transportation planning process
  2. Uses the information, analysis, and products developed during planning to inform the environmental review process.

Planning study report

I-5 Tumwater to Mounts Road study area map