This report develops a methodology for estimating the effects of different categories of overweight trucks on NYSDOT pavements and bridges. A data mining algorithm is used to categorize truck data collected at several Weigh-In-Motion stations around the state of New York based on the trucks’ adherence to the state’s legal weight limits. The data indicate that about 11% of the trucks traveling on New York highways may be carrying divisible load permits, 1% may be carrying special hauling permits, while about 6% may be illegally overweight.