This paper presents the results of the validation of the pavement Remaining Service Interval (RSI) concept using data and models from a State Highway Agency in the United States. The RSI terminology was developed to replace the confusion caused by the multitude of meanings assigned to the various forms of pavement Remaining Service Life (RSL). The RSI concept considers the complete sequence of Maintenance and Rehabilitation (M&R) activities of the pavement system and does not simply consider the end of life as promulgated by the RSL philosophy. The validation was performed by first replicating a portion of the agency’s Pavement Management System (PMS), and then modifying the system to include the RSI. The objective of the validation was to determine whether the RSI approach resulted in consistent prediction of treatment needs, performance and costs over the long term. As part of the validation effort, an improved approach to global optimization using genetic algorithms and concepts based on simulated annealing was used, and the implications of the analysis period on the RSI results was investigated. The results of the analysis demonstrated that the RSI is a valid approach that can lead to enhanced business practices for agencies, and can be used to effectively communicate the M&R needs of a pavement. In addition, it was shown that the RSL of a pavement was not related to the time until the next treatment should be applied based on an optimal treatment strategy.