Washington State Department of Transportation (2014). Washington State Highways, 2014–2015(PDF) (Map). 1:842,000. Olympia: Washington State Department of Transportation. Puget Sound inset. Retrieved August 17, 2020.
"2016 Annual Traffic Report"(PDF). Washington State Department of Transportation. pp. 154–155. Archived from the original(PDF) on August 12, 2017. Retrieved August 17, 2020.
"2016 Annual Traffic Report"(PDF). Washington State Department of Transportation. pp. 154–155. Archived from the original(PDF) on August 12, 2017. Retrieved August 17, 2020.