Streets data includes: Arterial Classification, Street Names, Block Number, Direction, One-way, Surface Width, Surface Type, Pavement Condition, Speed Limit, Percent Slope.   From the Hansen Asset Management System:

The linework is from the SND(Street Network Database) which can be found at our open data site - https://data-seattlecitygis.opendata.arcgis.com/datasets/street-network-database-snd.  

| Attribute Information: https://www.seattle.gov/Documents/Departments/SDOT/GIS/Seattle_Streets_OD.pdf 

| Update Cycle: Weekly
| Contact Email: DOT_IT_GIS@seattle.gov

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Common SDOT queries and data downloads   
| Arterial Classification: of Seattle Streets
ARTCLASS IN(1,2,3,4)

| Transit Classification: of Seattle Streets
TRANCLASS IN(1,2,3,4,5,6)