The report describes the research performed and the findings of the PATH Task Order 6303 “Optimal Use of Changeable Message Signs for Displaying Travel Times”. First, travel time estimation methods from various sources are evaluated against probe vehicle data. Next, a survey of San Francisco Bay Area commuters was undertaken regarding the perception and preference for displaying travel times on CMS. Finally, a model that evaluates the CMS impacts on network traffic and determines optimal CMS configurations was developed and tested. Deployment guidelines for CMS are presented based on these results.