In the absence of built-in flexibility for adapting sales tax measures to changing transportation needs and closer alignment with statewide GHG goals and other sustainability, economic, and quality of life objectives, regions are potentially locking a large portion of their sales tax measure revenues into an inflexible long-term investment strategy and suboptimal outcomes. This lack of flexibility has a domino effect requiring significant portions of formula federal and state funds to be matched with the sales tax measure project lists to achieve their construction. It also holds potential negative impacts in the playing field of competitive funding sources described in this report, since both innovative projects and leveraging other sources of funding are key for winning funds from cap-and-trade and other programs.