The purpose of this report is to document how the Travel Efficiency Assessment Method previously used for a national assessment could be applied to specific regions to estimate the reductions in vehicle miles traveled (VMT), greenhouse gas (GHG) emissions, and criteria pollutant emissions. The U.S. Environmental Protection Agency (EPA) collaborated with state and local government officials in three regions to complete these case studies: Pima County Association of Governments (PAG) for the Tucson, AZ region, Massachusetts Department of Transportation (MassDOT) for the Boston, MA region, and Mid-America Regional Council (MARC), for the Kansas City, MO Region. EPA offered technical assistance and the collaborating agencies offered their time, expertise, and local data to assess reductions in greenhouse gas (GHG) and criteria emissions from a set of travel efficiency strategies selected by and tailored to each particular region. Travel efficiency strategies represent the broad range of strategies designed to reduce travel activity, especially single-occupancy travel. The term travel efficiency strategies builds on the traditional Transportation Control Measures (TCMs) listed in Section 108(f)(1)(A) of the Clean Air Act (CAA) such as provision of transit, high-occupancy vehicle (HOV) lanes, and park and ride lots, and includes other strategies such as transportation pricing such as parking pricing and per-mile pricing and smart growth, such as transit-oriented development.