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

Planning study news

Thank you for visiting the Planning and Environmental Linkages Study virtual public open house to view information and give us your feedback.

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. That study is referred to as the Corridor Study and was completed in 2020.

The study strategies that were developed in the Corridor Study were further evaluated and refined in the Planning and Environmental Linkages Study (PEL Study).

Spring 2020 - Spring 2022


The "Planning and Environmental Linkages Study" (PEL study) built upon the goals and strategies outlined in the original 2020 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