2000 On-Road Mobile Source Episode-Specific Emissions Inventories for the Houston-Galveston Ozone Nonattinament Area (TTI-2002-11)

This Technical Note documents the methods used to develop the Houston-Galveston area (HGA) ozone nonattainment August 2000 base case episode-specific on-road mobile source emissions estimates (2007 attainment date analyses documentation associated with this task are provided in a separate Technical Note). The HGA counties are: Brazoria, Chambers, Fort Bend, Galveston, Harris, Liberty, Montgomery, and Waller. The period for emissions estimates for these eight counties includes 11 days, three prior to the ozone episode, August 22, 23, and 24; and the ozone episode days, August 25, 26, 27, 28, 29, 30, 31, and September 1. Emissions of volatile organic compounds (VOC), carbon monoxide (CO), and oxides of nitrogen (NOx), are estimated for each day on an hourly basis. The hourly estimates are computed by network link for which the geographical coordinates are provided. Emissions are categorized by 28 vehicle types and 14 pollutant?specific emissions types. Documented within are the methods relating to calculating inventory elements including linkbased vehicle miles traveled (VMT) estimates from Houston-Galveston Area Council's (HGAC) travel demand model (TDM), August day-of-week-adjusted Highway Performance Monitoring System (HPMS) VMT control totals, VMT mix, speeds, MOBILE6 emissions factors, and the emissions estimates.