The Federal Highway Administration (FHWA) has been encouraging states to better monitor and track work zone operational performance. The use of mobility performance measures will enable agencies to better assess the contribution of work zones to network congestion, identify specific projects that are in need of remedial action, and potentially assess penalties to contractors creating excessive impacts. A major challenge in implementing work zone mobility performance measures has been the availability of traffic condition data. States have become increasingly interested in using travel time data from private sector vendors to generate this information since this data set offers the ability to obtain condition information over a wide area without deploying any sensor infrastructure. This paper summarizes lessons learned about using private sector data to develop project-level work zone mobility performance measures based on experiences in Virginia. A series of case studies are used to show considerations in using private sector data to develop delay and queue length performance measures at four sites. Issues related to the spatial and temporal granularity of the data are discussed, as well as the ability of the data to reflect performance at urban and rural sites. This information can help guide agencies to better construct new mobility performance measurement programs using this data source.