Mobile Source Inventories for SIPs Matt Laurita Air Quality Modeling and Transportation Section EPA Region 4

What You Need MOBILE6.2 model MOBILE6.2 model “Technical Guidance on the Use of MOBILE6 for Emission Inventory Preparation” “Technical Guidance on the Use of MOBILE6 for Emission Inventory Preparation” Vehicle Miles Traveled (VMT) and Speeds Vehicle Miles Traveled (VMT) and Speeds Base year and estimated future values Base year and estimated future values Local data Local data Fleet age distribution, fleet mix, meteorological data Fleet age distribution, fleet mix, meteorological data Control programs Control programs Inspection & Maintenance (I/M), anti-tampering, etc… Inspection & Maintenance (I/M), anti-tampering, etc… For PM 2.5 : AP-42, Chapter 13 For PM 2.5 : AP-42, Chapter 13

What You Need NONROAD2004 Model NONROAD2004 Model Emissions and Dispersion Modeling System (EDMS) Model Emissions and Dispersion Modeling System (EDMS) Model “Procedures for Emission Inventory Preparation – Volume IV: Mobile Sources” (EPA ) “Procedures for Emission Inventory Preparation – Volume IV: Mobile Sources” (EPA ) Category 3 Marine Diesel Engines - Final Emission Standards Final Regulatory Support Document (EPA420-R ) Category 3 Marine Diesel Engines - Final Emission Standards Final Regulatory Support Document (EPA420-R ) Final Regulatory Impact Analysis: Control of Emissions from Marine Diesel Engines (EPA420-R ) Final Regulatory Impact Analysis: Control of Emissions from Marine Diesel Engines (EPA420-R )

MOBILE6.2 EPA’s approved motor vehicle emissions model EPA’s approved motor vehicle emissions model MOBILE6.2 is used for MOBILE6.2 is used for SIP development SIP development Transportation conformity Transportation conformity Emission inventories Emission inventories Special studies Special studies

MOBILE6.2 Computer model that predicts vehicle emissions on a grams per mile basis Computer model that predicts vehicle emissions on a grams per mile basis Freely available (download) Freely available (download) DOS based DOS based Contains default national data on fleet mix, average speeds, age distributions, etc… Contains default national data on fleet mix, average speeds, age distributions, etc… User can input detailed local data User can input detailed local data

Input local data and run MOBILE6.2 Input local data and run MOBILE6.2 MOBILE6.2 will generate Emission Factors (EF) MOBILE6.2 will generate Emission Factors (EF) EF are in units of grams per mile EF are in units of grams per mile EF can be generated for NOx, VOC, CO, NH 3, SOx, direct PM, brake & tire PM, and air toxics EF can be generated for NOx, VOC, CO, NH 3, SOx, direct PM, brake & tire PM, and air toxics Using the appropriate EF: Using the appropriate EF: Emissions = EF x VMT General Procedure

Required Data Calendar year ( ) Calendar year ( ) Minimum / maximum temperatures Minimum / maximum temperatures Fuel volatility (Reid Vapor Pressure, RVP) Fuel volatility (Reid Vapor Pressure, RVP) Diesel sulfur content Diesel sulfur content

Important MOBILE6.2 Inputs Meteorological data Meteorological data Minimum and maximum temperatures Minimum and maximum temperatures Absolute or relative humidity Absolute or relative humidity Should be consistent with the modeled episode Should be consistent with the modeled episode Evaluation month Evaluation month January (1) or July (7) January (1) or July (7) This only affects the vehicle fleet (i.e. fleet turnover from January to July) This only affects the vehicle fleet (i.e. fleet turnover from January to July) Typically use January for CO, July for Ozone Typically use January for CO, July for Ozone

Important MOBILE6.2 Inputs PM 2.5 emissions calculated as annual emissions PM 2.5 emissions calculated as annual emissions Requires MOBILE6 run for each month in an analysis year Requires MOBILE6 run for each month in an analysis year Example – Calculating emissions for 2005 Example – Calculating emissions for 2005 Month Cal Year Eval Month Month Cal Year Eval Month Jan20051Jul20057 Feb20051Aug20057 Mar20051Sep20057 Apr20057Oct20061 May20057Nov20061 Jun20057Dec20061 Note that RVP may vary by month, as well

Local Data – I/M Program Source: State Air Agency Source: State Air Agency What you need to know: What you need to know: Program type: Two-Speed Idle, ASM, On-Board Diagnostics (OBD) Program type: Two-Speed Idle, ASM, On-Board Diagnostics (OBD) Vehicle model years covered Vehicle model years covered Actual or anticipated start date of the program Actual or anticipated start date of the program Compliance rate Compliance rate Waiver rate Waiver rate

Local Data – VMT Mix Source: MPO, DOT Source: MPO, DOT Percentage of VMT generated by different vehicle classes (e.g. passenger cars, light-duty trucks, buses, etc.) Percentage of VMT generated by different vehicle classes (e.g. passenger cars, light-duty trucks, buses, etc.) MOBILE6.2 input uses 16 vehicle classes MOBILE6.2 input uses 16 vehicle classes Local data may not use as many classes Local data may not use as many classes You may have to convert! (See Technical Guidance) You may have to convert! (See Technical Guidance) Each roadway classification can have a different mix Each roadway classification can have a different mix

Local Data – Age Distribution Source: DMV, I/M Data Source: DMV, I/M Data MOBILE6 includes a default percentage of vehicles of each age from 0 to 25 years old MOBILE6 includes a default percentage of vehicles of each age from 0 to 25 years old Vehicles older than 25 years are included with 25-year-old vehicles Vehicles older than 25 years are included with 25-year-old vehicles Local data can significantly affect the emission estimates Local data can significantly affect the emission estimates

Local Data – Vehicle Speeds Source: MPO, DOT Source: MPO, DOT Forecast by travel demand models (TDM) or other methods Forecast by travel demand models (TDM) or other methods Can be input as Can be input as One average speed for each road classification (e.g. Interstate, Other freeway, Principal Arterial, Minor Arterial, Collector, Local) One average speed for each road classification (e.g. Interstate, Other freeway, Principal Arterial, Minor Arterial, Collector, Local) Distribution of speeds on each roadway for each hour of the day Distribution of speeds on each roadway for each hour of the day

Local Data – VMT Source: MPO, DOT Source: MPO, DOT Often forecast by travel demand models (TDM) Often forecast by travel demand models (TDM) If no model: extrapolation of historic traffic counts If no model: extrapolation of historic traffic counts Typically varies by roadway classification (6 Urban and 6 Rural classes) Typically varies by roadway classification (6 Urban and 6 Rural classes) Reminder: VMT is not a MOBILE6.2 input, but is used for post-processing Reminder: VMT is not a MOBILE6.2 input, but is used for post-processing

What if you don’t have local data? MOBILE6.2 includes national defaults for almost all inputs MOBILE6.2 includes national defaults for almost all inputs Minimum data requirements Minimum data requirements temperature, fuel volatility, and year of evaluation temperature, fuel volatility, and year of evaluation This will give you a less exact estimate for your area This will give you a less exact estimate for your area Use all local data that is available to you and supplement with defaults where necessary Use all local data that is available to you and supplement with defaults where necessary

Federal programs Do you need to worry about Tier 2, low sulfur gasoline and the Heavy-Duty Diesel Rule? Do you need to worry about Tier 2, low sulfur gasoline and the Heavy-Duty Diesel Rule? No. MOBILE6.2 already accounts for Federal rules. No. MOBILE6.2 already accounts for Federal rules. However, areas required to implement reformulated gasoline must specify this input into MOBILE6.2 However, areas required to implement reformulated gasoline must specify this input into MOBILE6.2

Notes on PM Emissions Diesel sulfur content is a required MOBILE6.2 input for PM modeling Diesel sulfur content is a required MOBILE6.2 input for PM modeling MOBILE6.2 does not calculate re-entrained road dust or construction dust emissions MOBILE6.2 does not calculate re-entrained road dust or construction dust emissions There is no approved computer model There is no approved computer model Use the methodology in AP-42, Chapter 13, “Miscellaneous Sources” Use the methodology in AP-42, Chapter 13, “Miscellaneous Sources”

Completing the Analysis Average Speed vs. Link-Level Analysis Average Speed vs. Link-Level Analysis Average Speed Average Speed Treats each road functional classification as a whole Treats each road functional classification as a whole Example: One MOBILE6.2 run for freeways with single average freeway speed and VMT mix Example: One MOBILE6.2 run for freeways with single average freeway speed and VMT mix Freeway EF X Total VMT on Freeways = Emissions from freeway vehicles Freeway EF X Total VMT on Freeways = Emissions from freeway vehicles Repeat for arterials, collectors, etc…and sum the totals Repeat for arterials, collectors, etc…and sum the totals

Completing the Analysis Link-Level Link-Level Multiple MOBILE6.2 runs at different speeds for each roadway classification Multiple MOBILE6.2 runs at different speeds for each roadway classification Create a look-up table of EF based on speed and roadway type Create a look-up table of EF based on speed and roadway type Calculate emissions for each segment of roadway (link) based on classification and speed Calculate emissions for each segment of roadway (link) based on classification and speed Sum all of the link emissions together Sum all of the link emissions together

Resources From From MOBILE6.2 User Guide (EPA420-R ) MOBILE6.2 User Guide (EPA420-R ) MOBILE6.2 Policy Guidance (February 24, 2004) MOBILE6.2 Policy Guidance (February 24, 2004) Technical Guidance on the Use of MOBILE6.2 for Emission Inventory Preparation (EPA420-R ) Technical Guidance on the Use of MOBILE6.2 for Emission Inventory Preparation (EPA420-R ) From From AP-42, Chapter 13, “Miscellaneous Sources” AP-42, Chapter 13, “Miscellaneous Sources”

NONROAD2004 Airport Ground Support Airport Ground Support Agricultural Agricultural Construction Construction Commercial Commercial Lawn & Garden Lawn & Garden Logging Recreational Marine ATVs Snowmobiles Chain Saws Others Does not cover Aircraft, Locomotives, or Commercial Marine Vessels EPA’s approved emissions model for: Used for SIP development and emission inventories

NONROAD2004 Airport Ground Support Airport Ground Support Agricultural Agricultural Construction Construction Commercial Commercial Lawn & Garden Lawn & Garden Logging Recreational Marine ATVs Snowmobiles Chain Saws Others Does not cover Aircraft, Locomotives, or Commercial Marine Vessels EPA’s approved emissions model for: Used for SIP development and emission inventories

NONROAD2004 Contains national data for all equipment categories Contains national data for all equipment categories Equipment populations Equipment populations Load factors Load factors Activity levels Activity levels Can allocate emissions to the state or county level Can allocate emissions to the state or county level Calculates emissions by year, season, month, or day Calculates emissions by year, season, month, or day Also by weekend or weekday Also by weekend or weekday Can output emissions of NOx, VOC, CO, SOx and PM Can output emissions of NOx, VOC, CO, SOx and PM

NONROAD Local Data Local data always preferred Local data always preferred Source: Surveys Source: Surveys What data can you improve? What data can you improve? Population estimates Population estimates Activity estimates Activity estimates Allocations of equipment use by season or day of the week Allocations of equipment use by season or day of the week

NONROAD Local Data Source: NOAA, local sources Source: NOAA, local sources Temperatures Temperatures Should be consistent with temperatures used for on- road mobile inventory Should be consistent with temperatures used for on- road mobile inventory Source: State Air Agency Source: State Air Agency Specific fuel parameters Specific fuel parameters

NONROAD Local Data Local data is inputted by adjusting the model’s default data files Local data is inputted by adjusting the model’s default data files If sufficient data exists, emissions can be sub- allocated from the county to the sub-county level If sufficient data exists, emissions can be sub- allocated from the county to the sub-county level

EDMS FAA’s emissions model FAA’s emissions model Commercial and general aviation aircraft Commercial and general aviation aircraft Ground support equipment (also handled by NONROAD – be careful not to double-count!) Ground support equipment (also handled by NONROAD – be careful not to double-count!) Airport roadways (may be covered in on-road inventory) Airport roadways (may be covered in on-road inventory) Can also handle airport stationary sources and training fires (N/A for this purpose) Can also handle airport stationary sources and training fires (N/A for this purpose)

EDMS Default data Default data Aircraft / engine combinations Aircraft / engine combinations Time-in-mode (e.g. takeoff, climb out, approach, idle) Time-in-mode (e.g. takeoff, climb out, approach, idle) Ground support equipment by aircraft type Ground support equipment by aircraft type Takeoff weights and approach angles Takeoff weights and approach angles Mixing height (default 3000 ft above ground level (AGL)) Mixing height (default 3000 ft above ground level (AGL))

EDMS – Local Data Source: NOAA, local source Source: NOAA, local source Average annual temperature Average annual temperature Mixing height Mixing height Source: FAA, Airport Authority Source: FAA, Airport Authority Annual Landing-Takeoff (LTO) cycles for each type of aircraft (or aircraft / engine combination for commercial aircraft) Annual Landing-Takeoff (LTO) cycles for each type of aircraft (or aircraft / engine combination for commercial aircraft) Annual number of touch-and- goes (typically general aviation training aircraft) Annual number of touch-and- goes (typically general aviation training aircraft)

EDMS - Output Annual emissions of NOx, VOC, CO and SOx for aircraft and ground support equipment (GSE) Annual emissions of NOx, VOC, CO and SOx for aircraft and ground support equipment (GSE) PM10 for GSE (but not aircraft) PM10 for GSE (but not aircraft) Aircraft PM calculated by hand – limited data Aircraft PM calculated by hand – limited data EDMS is also capable of dispersion analysis, but that is not necessary for inventory development EDMS is also capable of dispersion analysis, but that is not necessary for inventory development

Locomotives Locomotive emissions not covered by a model Locomotive emissions not covered by a model Procedures for Emission Inventory Preparation – Volume IV: Mobile Sources, page 200 Procedures for Emission Inventory Preparation – Volume IV: Mobile Sources, page 200 Requires all local data Requires all local data

Locomotives – Local Data Class I, II, and III railroads Class I, II, and III railroads Line haul and switchyard Line haul and switchyard Line haul calculation: Line haul calculation: Emissions = Emission Factor x Annual Fuel Usage Emissions = Emission Factor x Annual Fuel Usage

Locomotives – Local Data Source: Interview with railroad operator Source: Interview with railroad operator Class I Class I Must determine the fuel usage in the nonattainment area Must determine the fuel usage in the nonattainment area Fuel Consumption Index = Systemwide Gross Ton Miles / Systemwide Fuel Consumption Fuel Consumption Index = Systemwide Gross Ton Miles / Systemwide Fuel Consumption Fuel Usage = Fuel Consumption Index * Traffic Density in the nonattainment area Fuel Usage = Fuel Consumption Index * Traffic Density in the nonattainment area Class I railroads should be able to provide this information (though they may view it as confidential) Class I railroads should be able to provide this information (though they may view it as confidential)

Locomotives – Local Data Class II & III Class II & III Typically smaller railroads Typically smaller railroads Do not keep same types of records as Class I Do not keep same types of records as Class I May be able to estimate fuel consumed in nonattainment area (e.g. by percentage of track in the area) May be able to estimate fuel consumed in nonattainment area (e.g. by percentage of track in the area) All fuel may be consumed in nonattainment area All fuel may be consumed in nonattainment area

Locomotives – Local Data Switchyard Locomotives Switchyard Locomotives Emissions = Number of yard locomotives X Annual emissions per yard locomotive Emissions = Number of yard locomotives X Annual emissions per yard locomotive Sources: Sources: Interviews with yard operators Interviews with yard operators Observation Observation

Developed as part of the National Emissions Inventory (NEI) Developed as part of the National Emissions Inventory (NEI) Emissions estimated by multiplying activity by an emission factor Emissions estimated by multiplying activity by an emission factor Commercial Marine emission factors and methodologies are found in Commercial Marine emission factors and methodologies are found in Final Regulatory Impact Analysis: Control of Emissions from Marine Diesel Engines (EPA420-R ) for Category 1 and Category 2 engines Final Regulatory Impact Analysis: Control of Emissions from Marine Diesel Engines (EPA420-R ) for Category 1 and Category 2 engines Category 3 Marine Diesel Engines - Final Emission Standards Final Regulatory Support Document (EPA420-R ) for Category 3 engines Category 3 Marine Diesel Engines - Final Emission Standards Final Regulatory Support Document (EPA420-R ) for Category 3 engines States encouraged to use local port traffic data to refine the NEI estimates States encouraged to use local port traffic data to refine the NEI estimates Commercial Marine Vessels

Resources NONROAD2004 (Draft) NONROAD2004 (Draft) Various technical reports Various technical reports EDMS ($45 to purchase) EDMS ($45 to purchase) Procedure for Emission Inventory Preparation - Volume IV: Mobile Sources (EPA ) Procedure for Emission Inventory Preparation - Volume IV: Mobile Sources (EPA ) Category 3 Marine Diesel Engines - Final Emission Standards Final Regulatory Support Document (EPA420-R ) Category 3 Marine Diesel Engines - Final Emission Standards Final Regulatory Support Document (EPA420-R ) Final Regulatory Impact Analysis: Control of Emissions from Marine Diesel Engines (EPA420-R ) Final Regulatory Impact Analysis: Control of Emissions from Marine Diesel Engines (EPA420-R )

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