This article presents a process to define the framework for an advanced Transit Signal Priority (TSP) algorithm. For this study, traffic and transit agencies from a broad range of municipalities in Ontario, Canada, provided their views and expertise on various TSP-related issues, including practical needs, design implementation, performance measures, and challenges in developing effective TSP control systems. Based on their inputs as well as the objectives of the project, a set of TSP control concept directions was developed that are characterized with different methodologies and technologies. A listing of selection criteria was also established to evaluate the proposed TSP concept directions. Using these criteria, a ranking and evaluation process was undertaken to select one final TSP control concept that is of interest to potential users of advanced TSP systems. The work described in this article provides a successful example of a process to build consensus among stakeholders for advancing TSP developments.