Motor Vehicle Emission Simulator (MOVES). MOVES is the U.S. Environmental Protection Agency’s (EPA) Motor Vehicle Emission Simulator. It helps the user to answer ”what if” questions, such as ”How would particulate matter emissions decrease in my state on a typical weekday if truck travel was reduced during rush hour?” or ”How does the total hydrocarbon emission rate change if my fleet switches to gasoline from diesel fuel?” The purpose of the tool is to provide an accurate estimate of emissions from mobile sources under a wide range of user-defined conditions.