 State Route 531 | ||||
|---|---|---|---|---|
 SR 531 highlighted in red | ||||
| Route information | ||||
| Auxiliary route of I-5 | ||||
| Maintained by WSDOT | ||||
| Length | 9.88 mi[1] (15.90 km) | |||
| Existed | 1991[2]–present | |||
| Major junctions | ||||
| West end |  Wenberg County Park in Lake Goodwin | |||
 I-5 in Marysville | ||||
| East end |  SR 9 in Arlington | |||
| Location | ||||
| Country | United States | |||
| State | Washington | |||
| County | Snohomish | |||
| Highway system | ||||
| ||||
State Route 531 (SR 531) is a short state highway in Snohomish County, Washington, United States. It runs from west to east along 172nd Street between Wenberg County Park on Lake Goodwin to a junction with SR 9 in southern Arlington, with an intermediate interchange with Interstate 5 (I-5) in Smokey Point. The highway is the primary access point for the Arlington Municipal Airport and the Smokey Point retail corridor.
SR 531 was created by the state legislature in 1991, using existing roads that were built in the early 20th century. Retail and housing development in the Smokey Point area triggered several expansion projects in the 1990s and 2000s to accommodate growing traffic volumes. The I-5 interchange was rebuilt and expanded between 2004 and 2010, including the addition of a loop ramp and a wider overpass. Its eastern terminus at SR 9 was converted into a roundabout in 2012.
- ^ Multimodal Planning Division (January 3, 2018). State Highway Log Planning Report 2017, SR 2 to SR 971 (PDF) (Report). Washington State Department of Transportation. pp. 1612–1616. Retrieved July 30, 2018.
- ^ "RCW 47.17.757: State route No. 531". Washington State Legislature. 1991. Retrieved July 30, 2018.