As more and more data is generated from a more connected, smart, dynamic transportation ecosystem public agencies will be faced with a number of questions on how to manage, protect, and share data. With the proper considerations addressed, there are many opportunities for data to serve a powerful tool for better system planning and management, to serve as a catalyst for new mobility service creations, and to advance cutting edge policy analysis. This white paper provides arguments in favor of strategic data sharing between stakeholders, outlines sharing mechanisms, and identifies challenges and open questions.