Abstract |
The United States Environmental Protection Agency's Motor Vehicle Emission Simulator - commonly referred to as MOVES - is a set of modeling tools for estimating emissions produced by onroad and nonroad mobile sources. MOVES estimates the emissions of greenhouse gases (GHGs), criteria pollutants, and selected air toxics. The MOVES model is currently the official model for use for state implementation plan (SIP) submissions to EPA and for transportation conformity analyses outside of California. The model is also the primary modeling tool to estimate the impact of mobile source regulations on emission inventories. MOVES calculates emission inventories by multiplying emission rates by the appropriate emission-related activity, applying correction and adjustment factors as needed to simulate specific situations, and then adding up the emissions from all sources and regions. An inventory can be pictured as a stool; the three legs of the stool are the emission rates, activity, and populations, while the seat is the inventory. The emission rates are inputs to the model specified for various "processes" including running exhaust, start exhaust, and a number of evaporative processes, among others. These processes also define the activity, populations, and technology inputs required. Vehicle population and activity data are critical inputs for calculating emission inventories from emissions processes such as running exhaust, start exhaust, and evaporative emissions. In MOVES, most running emissions are distinguished by operating modes, depending on road type and vehicle speed. Start emissions are determined based on the time a vehicle has been parked prior to the engine starting, known as a "soak". Evaporative emissions modes are affected by vehicle operation and the time that vehicles are parked. Emission rates are further categorized by source bins with similar fuel type, regulatory classification, and other vehicle characteristics. This report describes the sources and derivation for onroad vehicle population and activity information and associated adjustments as stored in the MOVES2014 and MOVES2014aa default databases. This data has been extensively updated from MOVES2010b and previous versions of MOVES. Emission measurement and rates, correction factor values, and information for nonroad equipment in the default database are described in other MOVES technical reports |