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Modeling and Inventories NONROAD Model 

NONROAD Model (nonroad engines, equipment, 

and vehicles) 

The NONROAD Model is intended for Windows 98 and later. Its primary use is for estimation 

of air pollution inventories by professional mobile source modelers, such as state air quality 

officials and consultants. NONROAD2008 updates NONROAD2005 to include new nonroad 

emission standards promulgated in 2008 related to small gasoline engines and pleasure craft. 

Listserver Information 

NONROAD2008a Model 

Documentation: User Guide 

Documentation: Technical Reports 

Other EPA NONROAD Model Documentation 

Other Nonroad Reference Material 

Related Links

Listserver Information 

Subscription Instructions 

NONROAD2008a Model 

(posted July 2009) 

ReadMe File -- known issues and updates to NONROAD2008 

Frequently Asked Questions: NONROAD2008 Emission 

Inventory Model (PDF) (5 pp, 190K, EPA420-F-09-021, April 2009) 

"EPA NONROAD Model Updates of 2008" International Emission 

Inventory Conference presentation of changes from 

NONROAD2005 (PDF) (29 pp, 100K, EPA420-F-09-020, April 2009) 

Overview & Full Installation Instructions - Please follow these 

instructions closely to install any NONROAD model files. 

NONROAD2008a Core Model and Data Files (ZIP) (3.0M) 

Graphic User Interface (GUI) full installation (ZIP) (3.9M) - 

includes nrgui.exe and all needed DLL/system files. If you 

already had the NONROAD2005 GUI installed on your system, then you only need to 

update the GUI executable (in nrgui08.zip) provided below. 

Graphic User Interface (GUI) (ZIP) (110K) - nrgui08.zip (version 2008.1.0), 

posted April 2009. If you have never installed the GUI on your current 

computer, you should use the full GUI installation above. 

Reporting Utility files -- There are no updates for these from NONROAD2005. So if 

you have the NONROAD2005 versions, you do not need to download these. 

Otherwise, download both of these: 

Reporting Utility version 2005c (ZIP) (712K) - reports.mdb file only, Posted 

3/27/2006. 

Auxiliary database files (ZIP) (260K) - nrdata.mdb and multi-year postprocessors, Posted 1/27/2006. 

MS-Access 2002 Runtime software (ZIP) (33M) - Needed to run Reporting Utility only 

if you do not already have a copy of Microsoft Access 2002(XP) or Access 2003. 

Suggested Nationwide Average Fuel Properties (PDF) (2 pp, 70K, EPA420-B-09-018, April 

NOTE: You will need 

Adobe Acrobat 

Reader, available as 

a free download, to 

view some of the 

files on this page. 

See EPA's PDF page

to learn more about 

PDF, and for a link 

to the free Acrobat 

Reader.

Modeling and InventoriesLast updated on Thursday, September 10, 2009

http://www.epa.gov/otaq/nonrdmdl.htm

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2009)- Suggested Diesel Fuel Sulfur Inputs and Gasoline Ethanol content by year, 

important for modeling diesel PM and SO2 emissions as well as all gasoline engine 

emissions. 

Source Code (ZIP) (440K) Fortran source for Core Model and Visual Basic source for 

GUI. Optional, for reference only. Not needed to run model. 

If you don't have unZIP software, here are some options. If you prefer to receive a CD that 

contains the non-ZIP'd model files, please email nonroad@epa.gov or fax 734-214-4939 with 

your request and mailing address. 

Documentation: User Guide 

This has not been updated for NONROAD2008. See the ReadMe or Frequently Asked 

Questions (PDF) (5 pp, 190K, EPA420-F-09-021, April 2009) document for additional information. 

NONROAD2005 User's Guide (PDF) (202 pp, 1.6MB, EPA420-R-05-013) 

Documentation: Technical Reports 

These reports were updated in either December 2005 or April 2004 and supersedes prior 

versions. They have not been updated for NONROAD2008. See the ReadMe or Frequently 

Asked Questions (5 pp, 190K, EPA420-F-09-021, April 2009) document for additional information. 

Temperature Corrections for Nonroad Exhaust Emissions, NR-001c (PDF) (4 pp, 33K, 

EPA420-R-05-014, December 2005) 

Conversion Factors for Hydrocarbon Emission Components, NR-002c (PDF) (6 pp, 55K, 

EPA420-R-05-015, December 2005) 

Exhaust Emission Effects of Fuel Sulfur and Oxygen on Gasoline Nonroad Engines, 

NR-003c (PDF) (8 pp, 111K, EPA420-R-05-016, December 2005) 

Seasonal and Monthly Activity Allocation Fractions for Nonroad Engine Emissions 

Modeling, NR-004c (PDF) (22 pp, 723K, EPA420-R-05-017, December 2005) 

Median Life, Annual Activity, and Load Factor Values for Nonroad engine Emissions

Modeling, NR-005c (PDF) (46 pp 518K, EPA420-P-04-005, April 2004) 

Nonroad Engine Population Estimates, NR-006d (PDF) (46 pp, 1.1MB, EPA420-P-05-022, 

December 2005) 

Calculation of Age Distributions in the Nonroad Model -- Growth and Scrappage, NR007c (PDF) (16 pp, 141K, EPA420-R-05-018, December 2005) 

Nonroad Engine Growth Estimates, NR-008c (PDF) (PDF, 13 pp, 208K, EPA420-P-04-008, 

April 2004) 

Exhaust and Crankcase Emission Factors for Nonroad Engine Modeling --CompressionIgnition, NR-009c (PDF) (135 pp, 599K, EPA420-P-04-009, April 2004) 

Exhaust Emission Factors for Nonroad Engine Modeling -- Spark-Ignition, NR-010e

(PDF) (50 pp, 1.1MB, EPA420-R-05-019, December 2005) 

Nonroad Spark-Ignition Engine Emission Deterioration Factors, NR-011c (PDF) (16 pp, 

127K, EPA420-R-05-023, December 2005) 

Nonroad Evaporative Emission Rates, NR-012c (PDF) (117 pp, 2.5MB, EPA420-R-05-020, 

December 2005) 

Refueling Emissions for Nonroad Engine Modeling, NR-013b (PDF) (8 pp, 151K, EPA420-

P-04-013, April 2004) 

Geographic Allocation of Nonroad Engine Population Data to the State and County 

Level, NR-014d (PDF) (29 pp, 226K, EPA420-R-05-021, December 2005) 

Weekday and Weekend Day Temporal Allocation of Activity In The NONROAD Model, 

NR-015a (PDF) (7 pp, 154K, EPA420-P-04-015, April 2004) 

Other EPA NONROAD Model Documentation 

April 2009 18th International Emission Inventory Conference (Baltimore) --

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NONROAD2008 Poster Presentation

EPA NONROAD Model Updates of 2008 (PDF) (28 pp, 100K, EPA420-F-09-020, April 

2009) 

May 2006 15th International Emission Inventory Conference (New Orleans) -

- NONROAD2005 Training

Presentation Slides (PDF) (220K) or 600K PPT 

April 2003 12th International Emission Inventory Conference (San Diego) -- 

NONROAD Paper

Paper: EPA's Newest Draft Nonroad Emission Inventory Model (PDF) (63K) 

Presentation Slides (PDF) (283K) or 436K PPT 

Nonroad Model Workshop #4, November 5, 2002: Ann Arbor: A 3-day modeling 

workshop was held in Ann Arbor, MI, November 5 through 7, 2002. Only the first day 

of the workshop (November 5) was devoted to NONROAD model. The second and 

third days were devoted to the MOVES model and MOBILE6 model, respectively. 

Presentations from the 1-day NONROAD Session: A "zip" file containing the 

agenda and all of the presentations in either "PDF" formats [361K ZIP] or 

PowerPoint97 formats [246K ZIP] 

Nonregulatory Nonroad Duty Cycles 

Archive of Previous Versions of the NONROAD Model and Documentation 

Other Nonroad Reference Material 

Locomotive emissions regulations & guidance 

Emission Factors for Locomotives (PDF) (9 pp, 260K, April 2009, EPA420-F-09-025) 

Aviation emissions regulations & guidance (aircraft and ground support equipment) 

Voluntary Emission Reduction Program for Airport Ground Support Equipment

(GSE Study and GSE Emissions Model) 

Estimating Commercial Marine Emission Inventories

EPA's 1992 marine inventory guidance document (Procedures for Emission Inventory 

Preparation, Volume IV: Mobile Sources, EPA420-R-92-009, December 1992) uses 

methodologies based on fuel consumption that were common at that time. Since 

then, we have developed new marine inventory methodologies as part of our 

rulemaking process for emission standards for commercial marine diesel engines. 

These methodologies are more similar to what we use for mobile sources generally, 

and rely on emission factors, population estimates, and usage characteristics. These 

methodologies are described in an EPA report ("Current Methodologies in Preparing 

Mobile Source Port-Related Emission Inventories," April 2009). We are currently using 

these methodologies to update our marine inventories. States and other stakeholders 

are encouraged to refer to the report and the inventories we prepared for our 

commercial marine diesel engine standards for use in developing their own 

inventories. Chapters 2 and 3 of the EPA report describe the methodologies for oceangoing vessels and harbor craft, respectively. Chapter 3 of the Draft Regulatory Impact 

Analysis (EPA420-D-09-002, June 2009) for EPA's 2009 proposed rule, "Control of 

Emissions from New Compression-Ignition Engines at or Above 30 Liters per 

Cylinder", contains our inventory estimates and a description of how those estimates 

were produced for Category 3 commercial marine vessels. Chapter 3 of the Final 

Regulatory Impact Analysis (EPA420-R-08-001a, May 2008) for EPA's 2008 rule, 

"Control of Emissions of Air Pollution from Locomotive Engines and Marine 

Compression Ignition Engines Less than 30 Liters Per Cylinder", contains our 

inventory estimates and a description of how those estimates were produced for 

Category 1 and 2 commercial marine vessels. 

Current Methodologies in Preparing Mobile Source Port-Related Emission 

Inventories (PDF) (116 pp, 3MB, April 2009) 

Draft Regulatory Impact Analysis: Control of Emissions of Air Pollution from

Category 3 Marine Diesel Engines (PDF) (500 pp, 12.4MB, EPA420-D-09-002, June 

2009) 

Final Regulatory Impact Analysis: Control of Emissions of Air Pollution from 

Locomotive Engines and Marine Compression Ignition Engines Less than 30 

Liters Per Cylinder (PDF) (739 pp, 10MB, EPA420-R-08-001a, May 2008) 

Commercial Marine Activity in the United States - Final Reports (posted Sept 

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23, 1999) 

Great Lake and Inland River Ports (PDF) (EPA420-R-99-019PDF, 360K) 

Deep Sea Ports (PDF) (1.0MB, EPA420-R-99-020) 

Both Reports in WordPerfect format and Tables as Excel5 

spreadsheets (590K ZIP) 

Emission Inventory Preparation

Procedures for Emission Inventory Preparation - Volume IV: Mobile Sources

(from National Transportation Library of the US Dept of Transportation) (also 

available as a PDF file, 3.1MB, EPA420-92-009, used to be listed as EPA-450/4-

81-026d revised) 

AP-42: Status of Work to Update AP-42 Nonroad Emission Factors 

"Nonroad Engine and Vehicle Emission Study Report," November 1991 (Publication 

no. EPA-21A-2001 or EPA460/3-91-002) 

README about NEVES including hardcopy ordering information 

Body of report (PDF) (1.8MB) 

Appendices (PDF) (7.7MB) 

Related Links 

National Mobile Inventory Model (NMIM) - A free, desktop computer application 

developed by EPA to help you develop estimates of current and future emission 

inventories for on-road motor vehicles and nonroad equipment. 

CARB Mobile Source Emission Inventory Branch (California Air Resources Board) 

 

For further information or assistance regarding this web page, please contact the ASD Info 

Line at 734- 214-4636 or email: nonroad@epa.gov. 

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