Nonroad Technical Reports

These reports focus on MOVES inputs and algorithms for construction equipment, lawn movers and a variety of other nonroad emission sources. MOVES also covers cars, trucks and other onroad sources. See the MOVES Onroad Technical Reports page for reports focused on MOVES onroad default inputs and algorithms.

Although the stand-alone NONROAD model is now incorporated into the MOtor Vehicle Emission Simulator (MOVES) model, many of the NONROAD technical reports still apply to the nonroad inputs and algorithms used in MOVES. The reports are listed below by NONROAD or MOVES version.

• MOVES4
• MOVES3
• MOVES2014b
• MOVES2014a
• NONROAD2008a
• NONROAD2005
• Draft NONROAD2004
• Draft NONROAD2003
• Draft NONROAD2002a and Earlier
• Prior Versions

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MOVES4 Nonroad Technical Reports

• Overview of EPA’s MOtor Vehicle Emission Simulator (MOVES4) (pdf) (1.6 MB, August 2023, EPA-420-R-23-019) provides a high-level overview of MOVES4, including references to technical documentation and other MOVES information.
• Fuel Supply Defaults: Regional Fuels and the Fuel Wizard in MOVES4 (pdf) (4.6 MB, August 2023, EPA-420-R-23-025)
• Speciation Profiles and Toxic Emission Factors for Nonroad Engines in MOVES4 (pdf) (1.5 MB, September 2023, EPA-420-R-23-013)

MOVES3 Nonroad Technical Reports

• Overview of EPA’s MOtor Vehicle Emission Simulator (MOVES3) (pdf) (1.1 MB, March 2021, EPA-420-R-21-004) provides a high-level overview of MOVES3, including references to technical documentation and other MOVES information.
• Overview of Progress and Findings from the Cross-EPA Coordination Effort for Understanding and Evaluating NO_X Emissions Discrepancies (pdf) (2.1 MB, November 2021, 454-R-21-008) describes work to understand discrepancies between modeled estimates of atmospheric NO_X and total reactive nitrogen (NO_Y) concentrations and ambient measurements and determine whether these discrepancies were driven by mobile source emissions estimates or other model processes.
• Speciation Profiles and Toxic Emission Factors for Nonroad Engines in MOVES3 (pdf) (2.1 MB, July 2022, EPA-420-R-22-015) This report was updated for MOVES3.0.4 in July 2022 and supersedes prior versions.
• Fuel Supply Defaults: Regional Fuels and the Fuel Wizard in MOVES3 (pdf) (5.3 MB, November 2020, EPA-420-R-20-017) This report was updated for MOVES3 in November 2020 and supersedes prior versions.
• Exhaust and Crankcase Emission Factors for Nonroad Compression-Ignition Engines in MOVES3.0.2 (pdf) (4.8 MB, September 2021, EPA-420-R-21-021) This report was updated for MOVES3.0.2 to correct the base fuel sulfur level for Tier 4 equipment.

MOVES2014b Nonroad Technical Reports

These reports were updated for MOVES2014b in July 2018 and supersede prior versions.

• Nonroad Engine Population Growth Estimates in MOVES2014b (pdf) (544 K, July 2018, EPA-420-R-18-010)
• Exhaust and Crankcase Emission Factors for Nonroad Compression-Ignition Engines in MOVES2014b (pdf) (15.4 MB, July 2018, EPA-420-R-18-009)
• Speciation Profiles and Toxic Emission Factors for Nonroad Engines in MOVES2014b (pdf) (1.46 MB, July 2018, EPA-420-R-18-011)
• Fuel Supply Defaults: Regional Fuels and the Fuel Wizard in MOVES2014b (pdf) (679 KB, July 2018, EPA-420-R-18-008)

MOVES2014a Nonroad Technical Reports

• Speciation Profiles and Toxic Emission Factors for Non-road Engines (pdf) (1.27 MB, November 2016, EPA-420-R-16-017)
• Fuel Supply Defaults: Regional Fuels and the Fuel Wizard in MOVES2014 (pdf) (487 K, November 2016, EPA-420-R-16-002)

NONROAD2008a Technical Reports

These reports were updated in either July 2010, December 2005 or April 2004 and supersede prior versions. They were updated for NONROAD2008a.

See Frequently Asked Questions About NONROAD2008 (PDF) (190 K, April 2009, EPA420-F-09-021) for additional information.

• Temperature Corrections for Nonroad Exhaust Emissions, NR-001c (pdf) (33 K, December 2005, EPA420-R-05-014)
• Conversion Factors for Hydrocarbon Emission Components, NR-002d (pdf) (488 K, July 2010, EPA-420-R-10-015)
• Exhaust Emission Effects of Fuel Sulfur and Oxygen on Gasoline Nonroad Engines, NR-003c (pdf) (111 K, December 2005, EPA420-R-05-016)
• Seasonal and Monthly Activity Allocation Fractions for Nonroad Engine Emissions Modeling, NR-004c (pdf) (723 K, December 2005, EPA420-R-05-017)
• Median Life, Annual Activity, and Load Factor Values for Nonroad engine Emissions Modeling, NR-005d (pdf) (874 K, July 2010, EPA-420-R-10-016)
• Nonroad Engine Population Estimates, NR-006e (pdf) (1.1 MB, July 2010, EPA-420-R-10-017)
• Calculation of Age Distributions in the Nonroad Model -- Growth and Scrappage, NR-007c (pdf) (141 K, December 2005, EPA420-R-05-018)
• Nonroad Engine Growth Estimates, NR-008c (pdf) (205 K, April 2004, EPA420-P-04-008)
• Exhaust and Crankcase Emission Factors for Nonroad Engine Modeling – Compression-Ignition, NR-009d (pdf) (2.25 MB, July 2010, EPA-420-R-10-018)
• Exhaust Emission Factors for Nonroad Engine Modeling -- Spark-Ignition, NR-010f (pdf) (1.1 MB, July 2010, EPA-420-R-10-019)
• Nonroad Spark-Ignition Engine Emission Deterioration Factors, NR-011d (pdf) (616 K, July2010, EPA-420-R-10-020)
• Nonroad Evaporative Emission Rates, NR-012d (pdf) (2.7 MB, July 2010, EPA-420-R-10-021)
• Refueling Emissions for Nonroad Engine Modeling, NR-013b (pdf) (151 K, April 2004, EPA420-P-04-013)
• Geographic Allocation of Nonroad Engine Population Data to the State and County Level, NR-014d (pdf) (226 K, December 2005, EPA420-R-05-021)
• Weekday and Weekend Day Temporal Allocation of Activity In The NONROAD Model, NR-015a (pdf) (154 K, April 2004, EPA420-P-04-015)

NONROAD2005

• Temperature Corrections for Nonroad Exhaust Emissions, NR-001c (pdf) (33 K, December 2005, EPA420-R-05-014)
• Conversion Factors for Hydrocarbon Emission Components, NR-002c (pdf) (55 K, December 2005, EPA420-R-05-015)
• Exhaust Emission Effects of Fuel Sulfur and Oxygen on Gasoline Nonroad Engines, NR-003c (pdf) (111 K, December 2005, EPA420-R-05-016)
• Seasonal and Monthly Activity Allocation Fractions for Nonroad Engine Emissions Modeling, NR-004c (pdf) (723 K, December 2005, EPA420-R-05-017)
• Median Life, Annual Activity, and Load Factor Values for Nonroad engine Emissions Modeling, NR-005c (pdf) (46 pp 518 K, April 2004, EPA420-P-04-005)
• Nonroad Engine Population Estimates, NR-006d (pdf) (1.1 MB, EPA420-P-05-022, December 2005)
• Calculation of Age Distributions in the Nonroad Model -- Growth and Scrappage, NR-007c (pdf) (141 K, December 2005, EPA420-R-05-018)
• Nonroad Engine Growth Estimates, NR-008c (pdf) (208 K, April 2004, EPA420-P-04-008)
• Exhaust and Crankcase Emission Factors for Nonroad Engine Modeling --Compression-Ignition, NR-009c (pdf) (599 K, April 2004, EPA420-P-04-009)
• Exhaust Emission Factors for Nonroad Engine Modeling -- Spark-Ignition, NR-010e (pdf) (1.1 MB, December 2005, EPA420-R-05-019)
• Nonroad Spark-Ignition Engine Emission Deterioration Factors, NR-011c (pdf) (127 K, December 2005, EPA420-R-05-023)
• Nonroad Evaporative Emission Rates, NR-012c (pdf) (2.5 MB, December 2005, EPA420-R-05-020)
• Refueling Emissions for Nonroad Engine Modeling, NR-013b (pdf) (151 K, April 2004, EPA420-P-04-013)
• Geographic Allocation of Nonroad Engine Population Data to the State and County Level, NR-014d (pdf) (226 K, December 2005, EPA420-R-05-021)
• Weekday and Weekend Day Temporal Allocation of Activity In The NONROAD Model, NR-015a (pdf) (154 K, April 2004, EPA420-P-04-015)

NONROAD2005 Training Presentation Slides, May 2006 15th International Emission Inventory Conference (New Orleans)

• NONROAD2005 Training Presentation Slides, May 2006 15th International Emission Inventory Conference (New Orleans) (pdf) (222.03 KB)

The presentation is also available as a PowerPoint file: NONROAD2005 Training (PPT) (ppt) (309 KB)

Draft NONROAD2004 updates (April 2004) that supersede prior versions

• RVP and Temperature Corrections for Nonroad Engine Modeling, NR-001b (pdf) (216 K, April 2004, EPA420-P-04-002)
• Conversion Factors for Hydrocarbon Emission Components, NR-002b (pdf) (186 K, April 2004, EPA420-P-04-001)
• Exhaust Emission Effects of Fuel Sulfur and Oxygen on Gasoline Nonroad Engines, NR-003b (pdf) (207 K, April 2004, EPA420-P-04-003)
• Seasonal and Monthly Activity Allocation Fractions for Nonroad Engine Emissions Modeling, NR-004b (pdf) (282 K, April 2004EPA420-P-04-004)
• Median Life, Annual Activity, and Load Factor Values for Nonroad engine Emissions Modeling, NR-005c (pdf) (518 K, April 2004, EPA420-P-004-005)
• Nonroad Engine Population Estimates, NR-006c (pdf) (389 K, April 2004, EPA420-P-04-006)
• Calculation of Age Distributions in the Nonroad Model - Growth and Scrappage, NR-007b (pdf) (343 K, April 2004, EPA420-P-04-007)
• Nonroad Engine Growth Estimates, NR-008c (pdf) (208 K, April 2004, EPA420-P-04-008)
• Exhaust and Crankcase Emission Factors for Nonroad Engine Modeling --Compression-Ignition, NR-009c (pdf) (599 K, April 2004, EPA420-P-04-009)
• Exhaust Emission Factors for Nonroad Engine Modeling - Spark-Ignition, NR-010d (pdf) (319 K, April 2004, EPA420-P-04-010)
• Spark-Ignition Engine Emission Deterioration Factors for the Draft NONROAD2004 Emissions Model, NR-011b (pdf) (220 K, April 2004, EPA420-P-04-011)
• Basic Evaporative and Crankcase Emission Rates for Nonroad engine Modeling, NR-012b (pdf) (165 K, April 2004, EPA420-P-04-012)
• Refueling Emissions for Nonroad Engine Modeling, NR-013b (pdf) (151 K, April 2004, EPA420-P-04-013)
• Geographic Allocation of State Level Nonroad Engine Population Data to the County Level, NR-014c (pdf) (201 K, April 2004, EPA420-P-04-014)
• Weekday and Weekend Day Temporal Allocation of Activity In The NONROAD Model, NR-015a (pdf) (154 K, April 2004, EPA420-P-04-015)

Draft NONROAD2003

Paper and Slides on Draft Nonroad Emission Inventory Model: Presented at 12th International Emission Inventory Conference, April 2003

Abstract (from the attached paper):

The EPA is developing a mobile source emissions inventory model for nonroad equipment (NONROAD), which covers all equipment except locomotives, aircraft, and commercial marine vessels. The model will provide a tool for EPA, States, regional air pollution organizations, and local air pollution control agencies to use in estimating pollution from nonroad equipment for State Implementation Plans (SIPs), as required by the 1990 Clean Air Act Amendments and other regulatory needs.

This paper briefly describes the most current draft of the NONROAD model and how it version differs from prior versions. Nationwide model outputs are presented and compared for HC, CO, NOx, PM, SOx (SO2), and fuel consumption, for diesel and for sparkignition engines. In some cases, such as PM and SOx, the revised model projections are substantially different from earlier draft versions of the NONROAD model.

• EPA's Newest Draft Nonroad Emission Inventory Model: Presented at 12th International Emission Inventory Conference, April 2003 (pdf) (59.36 KB)
• EPA's Newest Draft Nonroad Emission Inventory Model (NONROAD), Presentation Slides (pdf) (282.31 KB)

The presentation is also available as a PowerPoint file 2003 NONROAD Presentation (ppt) (435.5 KB)
2003

Technical Reports from Draft NONROAD2002a and earlier

• RVP and Temperature Corrections, NR-001a (pdf) (37 K, December 2002, EPA420-P-02-011)
• HC Conversion Factors: VOC/TOG/ROG/etc, NR-002a (pdf) (134 K, June 2003, EPA420-P-03-002)
• Exhaust Emission Effects of Fuel Sulfur and Oxygen on Gasoline Nonroad Engines, NR-003a (pdf) (28 K, December 2002, EPA420-P-02-012)
• Seasonal and Monthly Activity Allocation Fractions, NR-004a (pdf) (82 K, December 2002, EPA420-P-02-010)
• Average Life, Annual Activity, and Load Factor Values, NR-005b (pdf) (205 K, December 2002, EPA420-P-02-014)
• Nonroad Engine Population Estimates, NR-006b (pdf) (205 K, December 2002, EPA420-P-02-004)
• Calculation of Age Distributions -- Growth and Scrappage, NR-007a (pdf) (50 K, June 2002, EPA420-P-02-017)
• Nonroad Engine Growth Estimates, NR-008b (pdf) (40 K, May 2002, EPA420-P-02-018)
• Exhaust Emission Factors -- Compression-Ignition, NR-009b (pdf) (590 K, November 2002, EPA420-P-02-016)
• Exhaust Emission Factors -- Spark-Ignition, NR-010c (pdf) ( 200 K, November 2002, EPA420-P-02-015)
• Spark-Ignition Engine Emission Deterioration Factors for the Draft NONROAD2002 Emissions Model, NR-011a (pdf) (130 K, April 2002, EPA420-P-02-019)
• Basic Evaporative and Crankcase Emission Rates, NR-012a (pdf) (36 K, December 2002, EPA420-P-02-002)
• Refueling Emissions for Nonroad Engine Modeling, NR-013a (pdf) (39 K, August 2002, EPA420-P-02-003)
• Geographic Allocation of State Level Nonroad Engine Population Data to the County Level, NR-014b (pdf) (93 K, July 2002, EPA420-P-02-009)
• Weekday and Weekend Day Temporal Allocation of Activity In The NONROAD Model, NR-015 (same as original) (pdf) (30 K, March 1999, EPA420-P-99-033)

Prior Versions of Technical Reports

Prior Versions of Technical Reports (zip) (2.74 MB)

• RVP and Temperature Corrections, NR-001 (posted November 13, 1997) - available as .txt and .pdf
• HC Conversion Factors: VOC/TOG/ROG/etc, NR-002 (pdf)
• Exhaust Emission Effects of Fuel Sulfur and Oxygen on Gasoline Nonroad Engines, NR-003 (pdf)
• Seasonal and Monthly Activity Allocation Fractions, NR-004 (pdf)
• Average Life, Annual Activity, and Load Factor Values, NR-005a (pdf)
• Nonroad Engine Population Estimates, NR-006a (pdf)
• Calculation of Age Distributions -- Growth and Scrappage, NR-007 (pdf)
• Nonroad Engine Growth Estimates, NR-008 (pdf)
• Exhaust Emission Factors -- Compression-Ignition, NR-009a (pdf)
• Exhaust Emission Factors -- Spark-Ignition, NR-010b (pdf)
• Exhaust Emission Factors -- Spark-Ignition, NR-010a (revision posted June 19, 1998)
  NOTE: See later revision NR-010b above, posted May 3, 1999.
  Attachments: (not revised)
  • compare.xls
  • tech1.wk4
  • techmix.wk4
• Emission Deterioration Factors For the NONROAD Emissions Model, NR-011 (pdf)
• Basic Evaporative and Crankcase Emission Rates, NR-012 (pdf)
• Refueling Emissions for Nonroad Engine Modeling, NR-013 (pdf)
• Geographic Allocation of State Level Nonroad Engine Population Data to the County Level, NR-014 (pdf)
• U.S. Maps of county-level indicators for nonroad equipment usage (GIF files):
  • employees in air transportation industry
  • dollar value of construction
  • acres of harvested cropland
  • number of public golf courses
  • number of single & double unit homes
  • number of employees in landscaping & horticultural services
  • number of employees in logging industry
  • number of employees in lumber & wood processing industry
  • number of employees in manufacturing
  • number of employees in metals mining
  • number of employees in coal mining
  • number of employees in oil & gas extraction industry
  • 1997 human population estimates
  • number of employees in RV parks & campsites
  • number of RV park & campsite establishments
  • water surface area
  • number of wholesale establishments
• Weekday and Weekend Day Temporal Allocation of Activity In The NONROAD Model, NR-015 (pdf)