The transportation infrastructure in the United States is entering a period of growth and expansion. During this period of change, attention has been directed towards improving the organizational accountability of the rapid rail transit systems. To date, there has been no definitive study of how rapid rail transit systems integrate the operating budgetary process into decisionmaking or whether doing so would provide greater control over costs. Based on field interviews, this study examines the budgetary process of 9 of the 13 rapid rail transit systems operating in the United States. Among the reasons examined are (1) administrative issues, (2) budgetary planning, (3) frame of reference, (4) investigating variations from plans, and (5) planning feedback. In addition to describing the similarities and differences among the rapid rail transit systems, recommendations and observations are presented.