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Air Pollution Control; Motor Vehicle Emission Factors

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Environmental Protection Agency (EPA).


Notice of public workshop.


The Environmental Protection Agency is now in the process of developing revisions and improvements to its mobile source emissions models (the MOBILE and NONROAD models) as well as planning a new generation of models (the MOVES model). The current version of the highway (on-road) model, MOBILE6, was released for use in January 2002. Draft extensions of this model (MOBILE6.1 adding particulate emissions and MOBILE6.2 adding toxic emissions) were released several months later. The extension of the model, MOBILE6.3 adding CO2 emissions, is planned for release in the fall of 2002. Revisions are also being made to the current draft NONROAD model. Finally, work is progressing on the MOVES model, with its first component (a greenhouse gas model) scheduled for completion in the fall of 2003. This notice announces a public workshop for the purpose of discussing issues raised by these present and future models.

At this three-day workshop, Mobile Source Present and Future Models, EPA will devote the entire first day to the NONROAD model, the entire second day to the MOVES model, and the entire third day to the MOBILE6 model. This will allow individuals to attend only the sessions in which they are interested.

On the first day (November 5), EPA we will cover the NONROAD model. While a formal agenda has not been completed, EPA will cover recent revisions to the draft NONROAD model, (including geographic allocation), data collection by EPA and the states, and nonroad categories not included in the model (i.e. aircraft, locomotives, and commercial marine). We will also cover our pilot project and hold a user forum.

On the second day (November 6), EPA will cover the MOVES Model. Tentative topics include the comprehensive plan for the Model, the Greenhouse Gas emission analysis plan and shootout follow up. Other topics include the Portable Emission Measurement System (PEMS) and the Portable Activity Monitoring System (PAMS) master plan, as well as the NATIONAL MOBILE INVENTORY MODEL (NMIM).

On the third day (November 7), the proposed agenda will cover the MOBILE6 Model including the MOBILE6 validation work and related sensitivity analysis that has been done. A discussion of the MOBILE6.1, MOBILE6.2, and MOBILE6.3 extensions will be held, with plans for the next release. We also tentatively plan to have a forum on MOBILE6 experiences, including questions and answers.


The workshop will be held Tuesday, November 5 through Thursday, November 7, 2002. Sessions are expected to run from 8:30 a.m. to 4 p.m., Eastern Daylight Time (EDT) each day. Please note that the first day of this workshop (November 5) is election day. Therefore, attendees may wish to make arrangements to vote via absentee ballots.


The workshop will be held at the Sheraton Inn, 3200 Boardwalk, Ann Arbor, MI 48108. Directions to the workshop can be obtained at A block of 50 rooms is being held at the Sheraton for attendees of this workshop under Code MSMW11 until October 4, 2002. The phone number is (734) 996-0600.

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(734) 214-4636 or send an e-mail to

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Under Section 130 of the Clean Air Act Amendments of 1990, EPA is required to review, and to revise as necessary, the emission factors used to estimate emissions of volatile organic compounds (VOC), carbon monoxide CO), and oxides of nitrogen (NOX) from area and mobile sources. In the case of highway vehicles, emission factors for these pollutants are estimated using the highway vehicle emission factor model, commonly referred to as MOBILE. This model, first developed in the late 1970s, has been revised, updated, and improved periodically since that time to account for improved data and analyses concerning in-use emissions performance of highway vehicles, changes in vehicle and emission control technology, changes in fuel composition, strengthening of applicable emission standards, refinements to applicable test procedures, and other items that affect in-use emission levels.

Section 130 of the Act requires that this emission factor review, and revision as needed, be performed at least every three years. As noted above, the current official version of the model, MOBILE6, was released January 2002. Since that time, two draft extensions to the model have been developed, MOBILE6.1 and MOBILE6.2. While not involving revision and update to the entire model, these versions were developed to address specific needs on the part of emission factor users. MOBILE6.1 added the calculation of particulate matter (PM) to the emissions calculated by MOBILE6. MOBILE6.2 added the calculation of toxic compounds to the emissions calculated by MOBILE6 or MOBILE6.1.

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Dated: August 27, 2002.

Margo Tsirigotis Oge,

Director, Office of Transportation and Air Quality.

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[FR Doc. 02-22366 Filed 8-30-02; 8:45 am]