Full Name

AASHTO R9 – Standard Practice for Acceptance Sampling Plans for Highway Construction


This standard practice provides guidelines in the preparation of statistically based acceptance plans using statistical and quality assurance (QA) principles.  The acceptance plans must be realistic, fair to both the contractor and agency, and statistically accurate.

This standard practice includes the basic criteria for the most common AASHTO applications. It uses the broad definition of acceptance plan to include the separate functions of both quality control (QC) and acceptance.

Other aspects are provided where deemed important, but should not be interpreted to define a complete QA program. References are given for more advanced criteria and special applications.


acceptance sampling plans; buyer’s risk; control charts; expected pay curve; operating characteristic curve; percent within limits; quality control; seller’s risk; stepped and continuous pay schedules; variability known; variability unknown