摘要: |
Since 1995, EPA has made available the PART5 model, a Fortran program that estimates particulate air pollution emissions of in-use gasoline-fueled and diesel-fueled highway motor vehicles. It calculates particle emission factors in grams per mile (g/mi) for on-road automobiles, trucks, and motorcycles, for particle sizes of 1-10 microns. The particulate matter (PM) estimates include emission factors for exhaust particulate, brake-wear, and tire-wear. The PART5 model is now outdated. MOBILE6 is the most recent EPA emission factor computer model. It calculates in-use fleet emission factors for three criteria pollutants: hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen (NOx). These emission estimates are made for gas, diesel and natural gas fueled cars, trucks, buses and motorcycles for calendar years 1952 through 2050. The model calculates emission factors under a wide variety of conditions affecting in-use emission levels, e.g., ambient temperatures, average traffic speeds, etc. MOBILE and PART5 have been used by EPA and other organizations in a variety of applications. These include evaluations of highway mobile source control strategies by state, local and regional planning agencies; emission inventories and control strategies for State Implementation Plans under the Clean Air Act; transportation plans and conformity analyzes by metropolitan planning organizations and state transportation departments; environmental impact statements by industry investigators; and academic research efforts. This document describes the methodology and algorithms used to combine PART5 and MOBILE6 to produce an integrated MOBILE6.2 model. This new model produces the same estimates for HC, CO and NOx emission as MOBILE6.0, but it also can estimate particulate emission factors like the PART5 model. The MOBILE6.2 particulate emission estimates differ somewhat from the PART5 estimates. The principal reasons for these differences are changes in vehicle registration and technology distributions between PART5 and MOBILE6 and the fact that some particulate emission rates for future model years have been updated in MOBILE6.2 to reflect recent rule-makings. |