The Oklahoma Department of Transportation (ODOT) Research and Development Division (R&D) installed field data acquisition systems in 1992 on five test pavement sections with a view to evaluate the performance of the drainable base and edge drain systems in Oklahoma. Rainfall, outflow and other data have been collected continuously since that time. The University of Oklahoma (OU), in association with ODOT, analyzed the field data, developed appropriate computer programs (written in SAS 6.08 language) to analyze the data, developed a simple, quick and efficient field test scheme to evaluate the drainage efficiency of the existing pavement sections, and conducted a number of field tests for this purpose. This report presents the results of these studies. The useful data, containing rainfall values and the corresponding outflow values reflecting the drainage characteristics of the pavement drainage system. were identified and grouped into a number of"events." The events were studied to establish any relationship between outflow and rainfall magnitudes, flow rates, time required to initiate flow in different types of pavements, and time required for drainage. This information was combined to determine the drainage efficiency of the corresponding drainable base and edge drain system . Finally, the time for 50% drainage was computed and compared with the AASHTO guidelines to determ ine the drainage quality of the pavements under investigation. This report presents the steps involved in grouping, analyzing and interpreting the field data, and explains the findings with appropriate textual and graphical illustrations. A field test procedure was developed to facilitate a quick examination of the quality of a pavement drainage system . The procedure for this field test, results of the field tests performed, and a comparison with regular rainfall and outflow data are also presented in this report.