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Roadside Safety Improvement Survey I-90 MP 255-270 Four Lakes/Tyler

What is the project?

The Washington State Department of Transportation plans to begin work to improve roadside safety along I-90 near Tyler to Four Lakes by removing basalt rock and trees within the median.

What is the purpose of this open house?

We are seeking input from all interested parties on options to improve median safety along I-90 near Four Lakes and Tyler, between MP 255 and 270 while considering preservation of the environment. The safety improvements will involve the removal of rock and trees within the median of the corridor.  Some of the rock and tree removal has the potential to impact the “visual value” along segments of the highway.  Historically, this corridor has had previous projects addressing the safety issues within the median and have encountered various levels of interest and concern from the public.  WSDOT has identified ten impacted areas along this stretch of I-90 with higher degrees of visual quality.  All other features within the median, with lower visual quality, will be regraded to improve safety.

I-90 Salnave aerial photograph and map

Why should the environment be protected?

WSDOT has been directed [via Executive Order E. 1018.02] to not only protect the safety of the traveling public, but to protect the environment.  It instructs WSDOT to “…make decisions and take actions that promote the conservation of resources for future generations by focusing on the balance of economic, environmental and community needs.” For this project, WSDOT is asking the community to consider safety and environmental needs.  In this instance, environmental needs are measured by visual quality.

What is visual quality?

I-90 Salnave visual quality

The Federal Highways Administration (FHWA) developed a system to help preserve the visual quality of the roadway, Visual quality is defined by the FHWA as the result of the interactive experience between viewers and their environment. While different viewers may have different opinions on a given view, within the purview of a transportation project FHWA considers the viewer will expect to see views anticipated to be in the area. As an example, while driving through a designated forest viewers will expect to see trees. This expectation has a direct link to how they perceive the visual quality of that particular view. These areas have been rated based on their visual quality, from moderately high to extremely high due to their unique geological structure and how they meet the FHWA standard.

View the entire report here

Here are examples of each:

Moderately high visual quality:

I-90 Salnave moderately high visual quality 1
I-90 Salnave moderately high visual quality 2

High visual quality:

I-90 Salnave high visual quality 1
I-90 Salnave high visual quality 2
I-90 Salnave high visual quality 3
I-90 Salnave high visual quality 4
I-90 Salnave high visual quality 5

Very high visual quality:

I-90 Salnave very high visual quality 1

Additional background

The roadside character along this section of I-90 is forested and open, native Ponderosa Pine vegetation mixing with open grasslands. Pockets of wetlands exist along the roadside. Houses are scattered through the area, but are seldom visible from the roadway. The landscape throughout the project was formed both by a series of lava flows and by the Missoula Floods. Lava flows have been found to be up to three miles in depth within the Columbia River Basalt area, making this one of only a handful of places on Earth where this type of geology is found. The weight of all this lava was heavy enough to depress the Earth’s crust and create the great basin of eastern Washington State. Later the Missoula floods carved out the channeled scablands, which extend across Washington State, from the Spokane area to the mouth of the Columbia River near Astoria. In areas where the floodwaters were swift, potholes formed which still exist as lakes today. I-90 is carved through a section of the channeled scablands throughout the project.