2013 Environmental Excellence in Design Award winners (Left to Right: Shane Spar, Chris Tams, Megan White, and Chad Simonson)
WSDOT is responsible for more than 20,000 lane-miles of roadway, nearly 3,000 vehicular bridges and 524 other structures. As part of that responsibility
Looking for technical information? Links to major topics can be found on the left hand side of this page. If you know of a specific subject you are looking for use the alpha index listed under Site Index .
Protecting air and water quality
Air Quality - Climate Change
In Washington, transportation accounts for nearly half (47%) of the total greenhouse gas emissions, including emissions from cars, trucks, planes, and ships.
WSDOT is developing effective, measurable and balanced emission reduction strategies. View Sustainable Transportation for details.
Wetlands - Since 1988, WSDOT has created 158 replacement wetland sites totaling 890 acres. These replacement sites can take a number of years to become self-sustaining, so WSDOT monitors and manages them for a period of years to ensure their success. During 2007, monitoring began on 21 new replacement sites, which total 149 acres.
Stormwater management – Statewide, WSDOT has approximately 40,000 acres of paved surfaces, which include roadway surfaces, park and ride lots, ferry terminals, safety rest areas and maintenance yards. Stormwater running off these surfaces, if left untreated, may pick up pollutants such as oil, fertilizers, pesticides, soil, trash and animal waste and carry them to rivers and streams. WSDOT uses a variety of methods to manage stormwater.
Erosion control during construction – When construction of transportation facilities disturbs soils, crews prevent erosion at these sites by spreading straw, planting grass, building ponds and other measures. Construction areas that have a high potential for erosion control due to the project area’s size, steepness, soil type or proximity to waterways are inspected by WSDOT weekly.
Our ferry system is currently working on a variety of projects designed to reduce pollution and improve the environment.
Fish passage - WSDOT began a program to remove barriers to fish, such as highway culverts, in 1991. Since then, we have evaluated all the culverts on the 7,056 miles of the highway system in order to identify which ones are barriers, and to prioritize the corrections that have the most benefit to fish. As of January 2013, we have removed 269 culverts that were barriers to fish, improving access to 904 miles of potential fish habitat.
Wildlife migration – Wildlife need to move across the landscape and highway corridors for seasonal migration, access to food and to establish new territories as the young mature. WSDOT works with the Department of Fish and Wildlife to identify wildlife corridors where there is significant wildlife movement. These corridors are considered during transportation planning, project development and maintenance operations.
Reducing animal kill - Approximately 3,000 collisions occur yearly with deer and elk on state highways. These collisions can result in serious injuries and fatalities to motorists. One of the ways we are protecting wildlife from highway collisions is through the use of Wildlife fencing and testing.
Historic and cultural preservation - WSDOT works to protect the cultural and historic resources. When impacts cannot be avoided, we consult with tribes and other state and federal agencies to minimize disturbance and mitigate effects. Cultural resources include:
- archaeological sites,
- historic structures (such as buildings and bridges) and
- areas of traditional cultural importance to tribes or other communities.
Social and community effects - Transportation projects often affect local communities. WSDOT looks at how transportation projects affect the social elements of an area including how neighborhoods are affected.
Vegetation management - WSDOT cares for and controls plants along the highway. WSDOT uses a combination of mechanical, manual and biological methods to control vegetation along roadsides. If managed properly, roadside vegetation can become self-sustaining over time and require less maintenance. This helps reduce maintenance costs and minimizes herbicide use.
WSDOT uses herbicides to maintain a vegetation-free strip at the edge of the pavement where necessary and to selectively control and eliminate undesirable plants, minimizing the use when possible. Between 2003 and 2007, we reduced herbicide use by 70 percent .
Litter control – WSDOT coordinates a volunteer army of 1,100 groups involved in its Adopt-A-Highway program. These volunteers pick up trash from sections of state highway several times each year. In 2007-2009, Adopt-A-Highway, Department of Ecology Youth Corps, and others picked up 6,075 tons of litter from state highways, which WSDOT disposed of at a cost of $3 million annually.
Roadside restoration – If a transportation project disturbs the roadside areas, WSDOT restores the landscape according to the characteristics of the surrounding area. For example, in an urban setting, we may restore the roadside to have a park-like appearance, whereas in a forested area, we would plant vegetation to blend in with the natural growth. Using native plants in roadside restoration will over the long term reduce maintenance requirements and costs. Native plant communities, once established, reduce soil erosion and will out-compete many weeds and undesirable plants that would otherwise be mowed or sprayed. A recent example of roadside restoration is SR 18 in the Maple Valley of King County.