COST EFFECTIVENESS OF SAMPLING AND TESTING PROGRAMS. EXECUTIVE SUMMARY

This report documents studies aimed at providing a means of establishing priorities among quality control tests and of optimizing sampling frequencies for each test, based on the effects of material properties measured on the performance of the pavements. Appropriate procedures were developed and are discussed in the report, including critical considerations and limitations due to lack of suitable stochastic models to predict performance and contractor response to changes in testing frequency. These procedures are embodied in computer program "COSTOP1", which was developed to assist State highway agencies in determining the optimum test frequency for a single test or the optimum test program for multiple tests to produce the greatest return for every dollar spent on testing. COSTOP1 is general and modular so that the testing programs for all paving construction and materials can be evaluated, and new models and differing repair strategies may be easily defined and input. Preliminary results based on limited models indicate that higher frequencies of testing than commonly used would be cost effective, decreasing the equivalent annual pavement costs by much more than the additional testing costs.