The Independent Assurance Program (IAP) is a part of the Iowa DOT Quality Assurance Program for Construction.† Appendix A contains the details of who is covered and what sampling and testing is covered in the program.


        Purpose of IAPó IAP is an unbiased and independent assessment of all sampling, testing, and testing equipment. This assessment includes evaluation of procedures and equipment used for the acceptance of highway materials and construction. 23 CFR Part 637 requires each state to have an IA Program.

        IAP is distinct from and not intended as an acceptance process or for use in verification of contractor sampling and testing results. IAP is distinct from and not intended for production quality control (QC) purposes. If IAP results indicate a potential problem with quality, the results may be used to initiate additional testing.

        IAP sampling shall be done in such a manner as to minimize variability. In order to eliminate material and process variability, split samples should be used. IAP samples may be taken independently of Agency verification or Contractor/Producer QC samples, or may be a split of a verification or an QC sample.

        Deficiencies in verification or QC processes that are identified through the IAP program must be investigated and resolved.

        IAP is an essential tool that helps to ensure integrity within the quality assurance (QA) program.


The IAP includes both system- and project-based approaches defined as follows:


        Project Approach. The frequency of IAP activities is based primarily on quantities of materials being tested and requires minimums (as per IM 204) on every project.† For projects with small quantities, project IAP will not be required:

††††††††††††††††††††††† HMA quantities less than 5000 tons

††††††††††††††††††††††† PCC paving quantities less than 5000 sq. yds.

††††††††††††††††††††††† PCC for structural and miscellaneous less than 50 cu. yds.††††††††††††††††††††††††††

††††††††††††††††††††††† Non-Proportioned aggregate less than 5000 tons.

††††††††††††††††††††††† Earthwork quantities less than 50,000 Yd3.

            System Approach. The frequency of IAP activities is based on time intervals, regardless of the number of tests, quantities of materials, or numbers of projects being tested by the individual and equipment being evaluated.† Each active technician should be checked at least 1 time per year. For HMA, the Districts Laboratories perform proficiency testing monthly during the construction season and field HMA laboratories perform proficiency testing at least 1 time per construction season.†† If a significant deficiency is observed for a technician, a later second check should be made.


Record keeping is required for all IAP observations and tests.† The record should include who and what was checked, when, where, and the outcome of the check.† An annual report is required by the FHWA detailing the system approach program- how many people for each test were checked, what was found, and how it was resolved.† Also any systematic issues should be detailed (i.e. problems with equipment or calibrations, need for additional training, improvements in test procedure instructions.).†