Statistical analysis of materials

View testing data and the Composite Pay Factor (CPF) of any contract in our computer program that statistically evaluates materials (SAM) according to the requirements of WSDOT Standard Specifications.

The Statistical Analysis of Materials (SAM) is a Materials Laboratory computer program that statistically evaluates materials according to the requirements of WSDOT Standard Specifications. The program will generate acceptance and verification reports with the capability of sending them electronically to both the WSDOT and to outside entities, as required.

Guest access

Allows contractors and others to access and view WSDOT testing data and the Composite Pay Factor (CPF) of any contract in SAM. Click on 'Login as guest' button and select the work order number (contract number) and the type of material in order to view the SAM data.

Design Builder access

If using the 2016, 2018 specifications, you may request Contractor access and we will give you access to specific projects. You can then enter your testing data for that project, and see the WSDOT data and the CPF.

SAM help for DOT employees (PDF 2.2MB)
SAM help file for contractors (PDF 1.1MB)

Traction tires are a special type of tire

manufactured with at least 1/8 of an inch tread. Traction tires are usually marked with a mountain/snowflake symbol, the letters M+S or “All Season.”

Carry chains, practice before leaving

Requiring chains keeps traffic moving during storms rather than closing a pass or roadway.

Prep your car. Fill up your gas tank,

pack jumper cables, ice scraper, warm clothing, snacks and water.