Efforts to accommodate increasing and dispersed demand for travel in the face of mounting traffic congestion, escalating construction costs, limited rights of way, and diminished air quality have caused planning agencies to adopt plans that would enhance transit choices. Faced with fiscal limitations, the need to prioritize the every-growing list of improvement projects is paramount. To meet this need in the development of the Bay Area System Plan for Regional Express Bus Service in California, a survey of existing literature on capital investment prioritization in transportation was conducted. This review led to development of a simple prioritization methodology with which to analyze the projects. Unit costs per ride were calculated to facilitate comparisons between the various proposals. The cost estimation procedure involved a systematic sequence of analyses that included the development and quantification of conceptual design elements, application of unit capital as well as operation and maintenance costs, and matching of annualized costs with annual ridership to derive unit costs per affected ride. Results revealed that the greater majority of proposed improvements could be implemented at a relatively low total cost. The estimates also suggest that most proposed improvements will not add very significant additional costs per ride to existing operations. The case study demonstrates the utility of a prioritization method that emphasizes the user benefits of projects and illustrates an approach that could be used by other agencies.