Protecting the environment

We strive to protect the natural environment and your community. Explore what we and our partners do to ensure our transportation system has a minimal impact on both.

Highways adjacent to rivers are often vulnerable to flooding, sedimentation, and washouts that can require expensive repairs and damage fish habitat. Learn how our CED program is constructing climate resilient, nature-based projects to protect the highway, improve fish habitat, and reduce needed repairs.

The public, agency staff, and contractors should use this page to report unplanned releases of materials on or near the highway and WSDOT-operated properties. 

Understanding future climate threats is essential for a safe and sustainable transportation system.

Learn how we're reconnecting streams under state highways to improve fish passage around the state.

Learn about the different types of historic bridges in Washington state, including the locations of the historical bridges and moveable bridges.

Learn about historic highways throughout the state.

Dealing with litter is a costly issue on Washington roads. We address it through litter collection programs and the Adopt-a-Highway program. Littering is illegal under Washington state law.

We design, construct and maintain our roadside areas to keep Washington highways safe and beautiful and to reduce maintenance costs.

Learn about how we manage stormwater runoff from paved surfaces like highways, rest areas, park-and-ride lots, ferry terminals, and maintenance facilities in urban areas throughout the state.

Find information about noise barriers, our process for determining where to build them and other options to reduce noise at your home.

Find out how we gather information on wildlife collisions and use it to reduce collisions and protect wildlife.

The Regional Road Maintenance Program improves roadway safety while safely maintaining our highways and following the Endangered Species Act.

Find examples of sustainability practices that we do in our work every day.

8,683 animals crossed the Snoqualmie Pass East Project area

as recorded by WSDOT and partners in 2020 and 2021.

46% increase in Amtrak Cascades ridership to 251,000 passengers

in 2021 compared to 172,000 in 2020.

Nine wetland and stream mitigation sites across 32.7 acres added

to our monitoring program in 2021 to help offset climate change impacts.