"Introduction: State Departments of Transportation (DOT) use performance management for a variety of functions from statewide budgeting and resource allocation to asset and systems management and executive dashboards. The concept of performance measurement@ or measurement on a regular basis of the results (outcomes) and efficiency of services or programs@ is nothing new in the public sector. Whether it was known as the RAND Corporation's ""systems analysis"" in the 1950s or Planning-Programming-Budgeting Systems (PPBS) in the late 1960s@ the need to better understand and control outcomes has always been recognized. Consistent with this trend in the public sector@ the use of performance measurement has been embraced by the federal@ state@ and local transportation agencies across the United States. The sheer breadth and complexity of the transportation network in this country@ however@ poses a significant logistical and conceptual challenge in the collection@ organization@ analysis@ and application of information based on performance measures as a whole. Fortunately@ as the result of the development of better tools and methods@ there are a number of successful performance-based transportation programs from which lessons can be drawn. As demonstrated by these examples@ the benefits of a performance-based highway program are numerous: ? It allows for more efficient allocation of increasingly scarce resources; ? It aids in the development and justification of budget and project proposals; and ? It holds government agencies responsible for funding@ constructing@ maintaining and operating the highway network accountable to the road users and the public at large. At the same time@ there are inherent limitations in performance measurement. First@ performance data do not@ by themselves@ tell why the outcomes occurred. Examining performance data does not tell the story behind the numbers@ nor provide the context under which such data was generated. Second@ some outcomes cannot be measured directly@ such as prevention of undesirable events. Third@ information provided through performance measurement is just part of the information managers and elected officials need to make decisions. Fourth@ because the range of factors and considerations faced by state DOTs around the country varies from state to state@ it is important to avoid using performance measures as a ""one-size-fits-all"" tool to rank and draw absolute conclusions of state DOT performance."