2018 SmartWay Rail Carrier 

Partner Tool: 

Technical Documentation 

U. S. Version 2.0.17 (Data Year 2017) 
2018 SmartWay Rail Carrier 

Partner Tool: 

Technical Documentation 

U. S. Version 2.0.17 (Data Year 2017)
 

Transportation and Climate Division 

Office of Transportation and Air Quality 

U.S. Environmental Protection Agency 

Office of Transportation and Air Quality 

EPA-420-B-18-007 

February 2018 
 

 

 

 

 

 

 

 

 

 

 

 

 

SmartWay 2.0.17 Rail Tool

Technical Documentation 

2-2-18 

1.0 Data Sources 

The technical approach recommended for the SmartWay railroad model was developed to 

encourage railroad participation by providing methods to calculate emissions, fuel 

consumption, and comparison metrics based, to the extent possible, on data the participating 

railroad companies have on hand and provide annually to the Department of Transportation's 

Federal Railroad Administration (FRA). For example, the approach presented uses data 

elements that Class 1 railway companies submit in their annual R-1 reports. Class I Railroad 

companies can use their most recent R-1 data for this SmartWay Tool. The relevant data 

reported annually to the FRA's R-1 forms include: 

Power Unit Information – Form 710 

Locomotive Unit Miles – Form 755, lines 8-14 

Railcar Miles by Type – Form 755, lines 15-84 

Fuel Consumption by Fuel Type and Unit Type – Form 750, lines 1-3 

Ton-Mile Data – Form 755, lines 104, 110, 113 

As Class 2 and 3 railroads do not need to provide detailed information to the FRA, in order for 

them to participate in the SmartWay Program they need to develop and submit the required 

data specific for their operations. Where a Class 2 or 3 railroad company does not have all of 

the required information, surrogate data are provided in the Appendix B of this report that may 

be useful to develop some of the basic data required for the Tool. 

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2.0 Emission Estimation 

Regardless of the locomotive class, the SmartWay Rail Tool was designed to calculate CO2 

performance metrics based on fuel consumption estimates, and NOx and PM emissions based 

on tier-specific engine operation information. 

In the SmartWay Rail Tool, the data for line-haul (including short line-haul and passenger rail) 

and yard operations are handled separately, even though many of the data elements are the 

same. Line-haul and yard operations are sufficiently different that they require separate 

emission factors associated with the different duty cycles. If operational surrogates are needed, 

then these should be compiled specific to either line-haul or yard operations. 

The specific Rail Tool calculation outputs include: 

a.	 total mass emissions (CO2, NOx, PM10 and PM2.5) 

b.	 g/ton-mile (gross, revenue, non-revenue) 

c.	 g/railcar-mile (just total miles) 

d.	 g/truck-equivalent-mile (just total miles) 

The following presents the calculation procedures used to estimate these performance metrics. 

1.	 Calculating mass emissions (total grams) 

a.	 CO2 1 

i.	 Diesel fuel: grams of CO2 = total gallons diesel (freight + passenger + switching) x 

10,180 g CO2/gallon. 

ii.	 Biodiesel: The Tool uses the biodiesel blend percentage to interpolate between 

regular diesel and 100% biodiesel fuel factors, with 100% biodiesel = 9,460 

g/gallon. Therefore 20% biodiesel (B20) has a fuel factor of 

10,180 – (10,180 – 9,460) x (20/100) = 10,036 g CO2/gallon 

iii.	 LNG: grams of CO2 = total gallons LNG (freight + passenger + switching) x 4,394 g 

CO2/gallon. 

iv.	 CNG: If input in cubic feet, grams of CO2 = total cubic feet (freight + passenger + 

switching) x 57.8. If CNG input is in equivalent gallons, the Tool multiplies total 

gallons by 7,030 g CO2/gallon. 

v.	 Electric: grams of CO2 = total kWh x 682 g CO2/kWhr. See Appendix C for 

details. 

1 With the exception of the electricity factors, the source of the fuel-based CO2 factors are discussed in the SmartWay Truck Tool 

Technical Documentation. 

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b.	 NOx and PM 

i.	 Diesel - Data Input Methods 2 and 4 (inputs differentiated by line-haul and 

switcher) 

1.	 The Tool first calculates the proportion of hrs/units by Tier level. 

a.	 The following provides an example for line-haul units – 

Tier Level Hrs Fraction 

Non-Tier - 3,000 hrs 0.15 

0 0 hrs 0.0 

0+ 1,000 hrs 0.05 

1 2,000 hrs 0.1 

1+ 5,000 hrs 0.25 

2 0 hrs 0.0 

2+ 4,000 hrs 0.2 

3 5,000 hrs 0.25 

4 0 hrs 0.0 

Total 20,000 hrs 1.00 

b.	 The Tool repeats this calculation for the switcher distribution 

c.	 The Tool then calculates weighted average fuel factors for NOx 

and PM, using the following table (source: 

http://www.epa.gov/oms/regs/nonroad/locomotv/420f09025.pdf). 

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Table 1 

Engine Tier Unit Type 

g/gal 

NOx PM10 PM2.5 

Non-tier 

Line-Haul/Passenger 270.40 6.66 6.46 

Switcher 264.48 6.69 6.49 

Tier 0 

Line-Haul/Passenger 178.88 6.66 6.46 

Switcher 191.52 6.69 6.49 

Tier 0 + 

Line-Haul/Passenger 149.76 4.16 4.04 

Switcher 161.12 3.50 3.40 

Tier 1 

Line-Haul/Passenger 139.36 6.66 6.46 

Switcher 150.48 6.54 6.34 

Tier 1 + 

Line-Haul/Passenger 139.36 4.16 4.04 

Switcher 150.48 3.50 3.40 

Tier 2 

Line-Haul/Passenger 102.96 3.74 3.63 

Switcher 110.96 2.89 2.80 

Tier 2+ 

Line-Haul/Passenger 102.96 1.66 1.61 

Switcher 110.96 1.67 1.62 

Tier 3 

Line-Haul/Passenger 102.96 1.66 1.61 

Switcher 68.40 1.22 1.18 

Tier 4 

Line-Haul/Passenger 20.80 0.31 0.30 

Switcher 15.20 0.23 0.22 

i.	 Example calculation for the weighted NOx 

factor for line-haul case above: 

Weighted average = 270.4 x 0.15 + 178.88 x 0.0 

+ 149.76 x 0.05 + 139.36 x 0.1 + 139.36 x 0.25 + 

102.96 x 0.0 + 102.96 x 0.1 + 102.96 x 0.25 = 

132.86 g/gal NOx 

ii.	 The Tool repeats these calculations for PM10/2.5 

iii. All calculations are then repeated for switchers 

2. The Tool multiplies gallons of (freight + passenger) diesel by weighted 

average fuel factors for line-haul/passenger category. 

3. The Tool multiplies gallons of switcher diesel by weighted average fuel 

factors for switchers. 

4. The Tool sums grams for line-haul/passenger and switchers to obtain total 

tons for NOx, PM10 and PM2.5. 

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ii.	 Diesel - Data Input Methods 1 and 3 (inputs NOT differentiated by line-haul and 

switcher) 

1.	 The Tool uses Table 2 to calculate the weighted average fuel factors2 

Table 2 

Engine Tier 

g/gal 

NOx PM10 PM2.5 

Non-Tier 269.96 6.66 6.46 

Tier 0 179.83 6.66 6.46 

Tier 0+ 150.61 4.11 3.99 

Tier 1 140.19 6.65 6.45 

Tier 1+ 140.19 4.11 3.99 

Tier 2 103.56 3.68 3.57 

Tier 2+ 103.56 1.66 1.61 

Tier 3 100.37 1.63 1.58 

Tier 4 20.38 0.31 0.30 

2.	 The Tool follows the same process as for Data Input Methods 2 and 4, 

but there is no need to sum across unit types (step 4 above). 

iii.	 Biodiesel – 

1.	 Biodiesel NOx and PM10/2.5 emissions are calculated by applying an 

adjustment factor to diesel emissions. Therefore the first is to multiply 

the biodiesel gallons by the diesel fuel factors as described above to 

calculate an unadjusted estimate for grams of NOx, PM10 and PM2.5. 

2.	 Next the Tool calculates adjustment factors based on % biodiesel blend 

specified – see Truck Tool Technical Documentation for references. 

a.	 % change in emissions = {exp[a × (vol% biodiesel)] - 1} × 100% 

Where a = 0.0009794 for NOx, and a = -0.006384 for PM10/2.5 

b.	 The Tool applies the adjustment factor to the unadjusted grams 

of NOx and PM10/2.5 calculated above. In general PM emissions 

are somewhat lower than diesel emissions, while NOx emissions 

increase slightly. 

iv.	 LNG – 3 

1.	 The Tool first sums total gallons of LNG across line-haul, passenger, and 

switchers 

2 The factors in Table 2 are calculated by weighting the line-haul/passenger and switcher values from Table 1 by the national 

average relative fuel consumption levels for these categories (0.925 and 0.075, respectively). National average values were 

obtained from 2010 R-1 reports. 

3 LNG, CNG, and Electricity factors do not vary with engine tier. Therefore, the Tool does not calculate weighted averages based on 

tier level distributions, but simply uses the gallons and/or kWh amounts from the Operations screen. 

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2.	 The Tool then multiplies total gallons by 20.3 g/gal to obtain grams NOx; 

and by 1.35 g/gal to obtain PM10. The Tool multiplies the gallons value 

by 1.31 to obtain PM2.5. See Appendix A regarding the source of these 

fuel-based factors. 

v.	 CNG – 

1.	 The Tool converts cubic feet of CNG to gallons if necessary with 1 

standard cubic foot of CNT = 0.00823 equivalent gallons. 

2.	 The Tool sums total gallons of CNG across line-haul, passenger, and 

switchers 

3.	 The Tool multiplies total gallons by 20.3 g/gal to obtain grams NOx; and 

by 1.35 g/gal to obtain PM10. The Tool multiplies the gallons value by 

1.31 to obtain PM2.5. See Appendix A regarding the source of these fuelbased factors. 

vi.	 Electricity – 

1.	 The Tool sums total kWh of electricity across line-haul, passenger, and 

switchers 

2.	 The Tool then multiplies total kWh by 0.690 to obtain grams NOx; by 

0.058 for grams PM10; and by 0.033 for grams PM2.5. See Appendix C for 

details. 

2.	 Calculate g/ton-mile for each pollutant (three types of “ton-miles”) 

a.	 Grams per gross ton-mile: the Tool divides the grams of each pollutant (fleet total) by 

gross ton miles entered on Operations screen. 

b.	 Grams per revenue ton-mile: the Tool divides the grams of each pollutant (fleet total) by 

revenue ton miles entered on Operations screen.4 

c.	 Grams per non-revenue ton-mile: the Tool divides the grams of each pollutant (fleet 

total) by non-revenue ton miles entered on Operations screen. 

3.	 Calculate g/railcar-mile for each pollutant5 

a.	 The Tool divides the grams of each pollutant by total railcar miles (the bold total on the 

Cars screen). 

4.	 Calculate g/truck-equivalent-mile 

a. The Tool first calculates the weighted average railcar volume for the entire fleet. 

i.	 The Tool uses the final volumes for each car type – these may be the defaults, 

provided by the user, or a combination thereof. The defaults represent the 

national average values derived from the 2010 R-1 reports, weighted by railcar 

miles – see Table 3 below. 

4 Value reported in SmartWay Public Bin Export Report. 

5 Value reported in SmartWay Public Bin Export Report. 

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ii.	 Using the distribution of total railcar miles by type as the weighting factors, the 

total railcar miles are summed (across Owned and Leased + private / Loaded + 

Empty – that is, the “Total” column on the Cars screen) for each type to 

determine the fractional contribution. Fractions must sum to 1.00. 

iii.	 The Tool applies weighting factors to final volumes by car type and sums across 

all car types to obtain final weighted average railcar volumes (in cubic feet). 

(NOTE: Since Class 2 and 3 operators do not provide railcar information, a 

national default value of 6,091 cubic feet per car is assumed for these carriers – 

see the Shipper Tool Technical Documentation for details). 

b.	 Calculate the “truckload equivalents” factor (TE): divide the weighted average railcar 

volume by 3,780 cubic feet.6 

c.	 g/truck-equivalent-mile = g/railcar-mile / TE, and is calculated for each pollutant. 

6 Truck industry average freight volume is 2.78 TEU = 3,780 cubic feet (see Shipper Tool Technical Documentation, p. 24). 

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Table 3. National Average Railcar Volume Data (Tool Defaults)* 

Type in Tool Railcar Type Cubic 

Feet 

Source/Assumption 

Key: Norfolk Southern (NS), Union Pacific (UP), Burlington Northern 

Santa Fe (BNSF), CSX Transportation (CSX), Guide to Railcars (GTRC), 

Chicago Rail Car Leasing (CRCL), Union Tank Car Company (UTCC), U.S 

Department of Agriculture (USDA) 

Box-Plain 50' + 

Box Equipped 

Boxcar 50 ft and 

longer including 

equipped boxcars 

7,177 Based on the average of the following boxcar types: 

50ft assumed to be 5694 [reflecting the average of 5355 (NS), 5431 

(UP), 5238 (CSX), 6175 (BSNF), 6269 (GTRC)]. 

60ft assumed to be 6,648 [reflecting the average of 6618 (NS), 6389 

(UP), 6085 (CSX), 7500 (BNSF)]. 

50ft high cube assumed to be 6,304 [reflecting the average of 6339 

(NS) and 6269 (CSX)]. 

60 ft high cube assumed to be 6917 [reflecting the average of 7499 

(NS), 6646 (CSX), and 6607 (GTRC)]. 

86ft assumed to be 9999 (NS). 

Autoparts assumed to be 7499 (NS). 

Box-Plain 40' Boxcar 40ft 4,555 Based on estimate of 50ft boxcar volume described above. Assumed 

40ft length would result in 20% reduction in volume. 

Flat TOFC/COFC 

Flat General 

Service 

Flat all other 

Flat car – all types 

except for multilevel 

6,395 Based on the average of the following flat car types: 

60ft assumed to be 6739 (BNSF). 

89ft assumed to be 9372(BNSF). 

Coil assumed to be 3387(NS). 

Covered coil assumed to be 5294 [reflecting the average of 8328 (NS) 

and 2260 (BNSF)]. 

Centerbeam assumed to be 6546 [reflecting the average of 5857 (UP) 

and 7236 (BNSF)]. 

Bulkhead assumed to be 7030 (BNSF). 

Flat Multi level 

Multi-level flat car 13,625 Based on the average of the following multi-level flat car types: 

Unilevel (that carry very large cargo, such as vehicles/tractors) 

assumed to be 12183 (NS). 

Bi-level assumed to be 14381(NS). 

Tri-level assumed to be 14313 (based on average of 15287 (NS) and 

13339 (BNSF). 

Flat Car – all typesincluding multi-level 7,428 Based on the average volumes of the flatcar types described above 

including multi-level as a single flat car type. 

Gondola Plain 

Gondola Equipped 

Gondola – all types 

Including equipped 

5,190 Based on the average of the following gondola car types: 

52-53ft assumed to be 2626 [based on average of 2665 (NS), 2743 

(CSX), 2400 (BNSF), and 2697(CRLC)]. 

60-66ft assumed to be 3372 [based on average of 3281 (NS), 3242 

(CSX), 3350 (BNSF), CRCL-3670, and 3366 (GTRC)]. 

Municipal Waste assumed to be 7999 (NS). 

Woodchip assumed to be 7781[based on average of 7862 (NS) and 

7700 (CRCL)]. 

Coal assumed to be 4170 [based on average of 3785 (NS) and 4556 

(BNSF)]. 

Refrigerator 

Mechanical 

Refrigerated nonmechanical 

Refrigerated ­

Mechanical /nonMechanical 

6,202 Based on the average of the following refrigerated car types: 

48-72ft assumed to be 6963 [based on average of 6043 (UP) and 7883 

(BNSF)]. 

50ft assumed to be 5167(GTRC). 

40-90 ft assumed to be 6476 [based on average of 6952 (UP) and 6000 

(BNSF)]. 

Hopper Open TopGeneral Service 

Open Top Hopper 4,220 Based on the average of the following open top hopper car types: 

42ft assumed to be 3000 (UP). 

54ft assumed to be 3700 (UP). 

60ft assumed to be 5188 [based on average of 5125 (UP) and 5250 

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Type in Tool Railcar Type Cubic 

Feet 

Source/Assumption 

Key: Norfolk Southern (NS), Union Pacific (UP), Burlington Northern 

Santa Fe (BNSF), CSX Transportation (CSX), Guide to Railcars (GTRC), 

Chicago Rail Car Leasing (CRCL), Union Tank Car Company (UTCC), U.S 

Department of Agriculture (USDA) 

(GTRC)]. 45ft+ assumed to be 4105 [based on average of 4500 (UP) 

and 3710 (BNSF). 

Woodchip assumed to be 7075 [based on average of 7525 (NS), 5999 

(UP), and 7700 (CRCL)]. 

Small Aggregate assumed to be 2252 [based on average of 2150 (NS), 

2106 (BNSF), and 2500 (CRCL)]. 

Hopper Covered 

Covered Top 

Hopper 

4,188 Based on the average of the following covered top hopper car types: 

45ft assumed to be 5250 (GTRC). 

Aggregate assumed to be 2575 [based on average of 2150 (NS) and 

3000 (CRCL)]. 

Small Cube Gravel assumed to be 2939 [based on average of 2655 

(NS), 3100 (CSX), and 3063 (BNSF). 

Med-Large Cube Ores and Sand assumed to be 4169 [based on 

average of 3750 (NS) and 4589 (BNSF)]. 

Jumbo assumed to be 5147 [based on average of 4875 (NS), 4462 

(CSX), 5175 (BNSF), and 6075 (CRCL)]. 

Pressure Differential (flour) assumed to be 5050 [based on average of 

5124 (NS) and 4975 (CRCL)]. 

Tank under 

22,000 gallons 

Tank Cars under 

22,000 gallons 

2,314 Assumes 1 gallon=0.1337 cubic foot (USDA). 

Based on small tank car average volume of 17304 gallons, which is the 

average of the following currently manufactured tank car volume 

design capacities of 13470, 13710, 15100, 15960, 

16410,17300,19900,20000,20590, and 20610 gallons (GTRC). 

Tank over 22,000 

gallons 

Tank Cars over 

22,000 gallons 

3,857 Assumes 1 gallon=0.1337 (USDA). 

Based on large tank car volume of 28851 gallons, which is the average 

of the following currently manufactured tank car volume design 

capacities of 23470, 25790, 27200, 28700, 30000, 33000, and 33800 

gallons (GTRC). 

All other cars 

Work Equip & 

company Freight 

No payment carmiles 

All Other Cars 5,014 Based on average volume presented above for each of the nine railcar 

types (all flatcars are represented by the line item that includes multilevel flatcars - 7428). 

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3.0 Activity Input Validation 

SmartWay has developed general validation criteria based on 2011 R-1 report data in order to 

perform range checks on Partner activity inputs. These range checks are simply intended to 

identify unreasonable data entries only. Table 4 summarizes the R-1 data used for each Class 1 

Rail Line, as well as the range check values derived from the carrier-specific data. Range check 

values are displayed in bold. 

Maximum acceptable values for fuel use, ton-miles, car-miles, and unit miles for Class 1 

operators were set equal to three times the rail-line specific maximum shown in the table. 

Similarly, minimum acceptable values for Class 1 operators were set equal to one tenth for fuel 

use, ton-miles, car-miles, and unit miles. Maximum acceptable values for Class 2 and 3 

operators were set at one tenth of the Class 1 maximum value. 

SmartWay will re-evaluate validation ranges to make them more precise, comprehensive, and 

consistent as Rail Partner data is collected in the future. 

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Table 4. 2011 R-1 Activity Data and Rail Tool Validation Ranges 

Rail Line 

Total Fuel 

Use (gallons 

diesel oil) 

Gross tonmiles total 

(thousands) 

Revenue 

Freight tonmiles 

(thousands) 

Nonrevenue 

Freight tonmiles 

(thousands) 

Total 

freight-car 

miles 

(thousands) 

Total 

Locomotive 

unit miles 

Locomotive 

Trainswitching 

unit miles 

Locomotive 

Yard 

switching 

unit miles 

BNSF 1,340,634,000 1,200,654,478 648,431,637 6,117,197 11,316,277 495,865,213 2,161,568 14,323,105 

CSX 500,735,225 456,207,620 228,394,651 1,216,165 4,789,143 186,017,342 6,557,484 14,352,854 

GTC 124,776,076 105,195,469 51,253,084 518,201 1,241,217 31,375,934 2,686,536 4,714,915 

KCSR 64,833,378 55,889,957 30,485,863 1,338,343 628,431 23,846,725 516,654 26,504,929 

NS 473,887,662 392,056,820 191,712,562 1,267,931 4,327,021 170,767,368 7,042,003 14,060,355 

Soo 72,442,000 70,325,676 34,581,354 333,090 807,927 27,407,979 2,686,353 2,577,600 

UP 1,117,851,152 1,072,705,764 544,397,317 5,485,720 11,012,608 424,786,444 12,635,406 19,169,964 

Class 1 max 4,021,902,000 3,601,963,434 1,945,294,911 18,351,591 33,948,831 1,487,595,639 37,906,218 79,514,787 

Class 1 min 6,483,338 5,588,996 3,048,586 33,309 62,843 2,384,673 51,665 257,760 

Class 2/3 max 134,063,400 120,065,448 64,843,164 611,720 1,131,628 49,586,521 1,263,541 2,650,493 

Class 2/3 min > 0 > 0 > 0 > 0 > 0 > 0 > 0 > 0 

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References 

Burlington Northern Santa Fe Railway (BNSF). Available at: 

http://www.bnsf.com/customers/how-can-i-ship/individual-railcar/#%23subtabs-3 

California Air Resource Board, Rail Yard Agreement, Sacramento, CA. 2007. 

Chicago Rail Car Leasing (CRCL), Rail Car Types. Available at: 

http://www.crdx.com/railcar.html 

CSX Transportation (CSXT), Customer Equipment. Available at: 

http://www.csx.com/index.cfm/customers/equipment/railroad-equipment/#boxcar_specs 

Guide to Railcars (GTRC), rail car types. Available at: 

http://www.worldtraderef.com/ 

Norfolk Southern Railway Company (NS), Customer Equipment. Available at: 

http://www.nscorp.com/nscportal/nscorp/Customers/Equipment_Guide/ 

Surface Transportation Board (STB), Industry Data, Economic Data, 

and Statistical Reports, Class 1 Annual Report Financial Form R-1. Available at: 

http://www.stb.dot.gov/stb/industry/econ_reports.html 

Union Pacific Railroad (UP), Customer Equipment, Car Types. Available at: 

http://www.uprr.com/customers/equip-resources/cartypes/index.shtml 

Union Tank Car Company, Chicago, IL, Basic Design Specifications. 

Available at: http://www.utlx.com/bdd_tank.html 

United States Code of Federal Regulations Title 40 Section Chapter 1, Subchapter Q, Part 

600.113, Fuel Economy Calculations. 

United States Department of Agriculture, Economic Research Service, 20005-4788, 

June 1992, Agricultural Handbook Number 697, Washington, DC. Available at: 

http://www.ers.usda.gov/publications/ah697/ah697.pdf 

U.S. Department of Transportation, Bureau of Transportation Statistics, Freight in America, 

January 2006. 

U.S. Department of Transportation, Surface Transportation Board, Form R-1. 

U.S. Environmental Protection Agency, 2009 Locomotive Emission Factor Study, Ann Arbor, MI. 

2009. 

14
 
 

U.S. Environmental Protection Agency, MARKAL Input Data for non-Light Duty Vehicles, 

Research Triangle Park, NC. 2009. 

U.S. Environmental Protection Agency, Regulatory Support Document: Locomotive Emission 

Standards Final Rule, 1997. 

15
 
 

 

Appendix A: Locomotive Emission Factors 

A-1. Fuel-based emission Factors 

Table A-1 – Line-haul Locomotive Emission Factors (grams per gal) 

Pollutant NOx PM10 CO2 

Diesel 270.402 6.662 10,180 

Biodiesel 

(B-20) 1731 7.881 9,4604 

CNG 7,0304 

LNG 20.33 1.353 3,8654 

1. MARKAL data (2009) 

2. EPA Locomotive Emission Factors (2009) 

3. ARB Rail Yard Agreement (2007) in terms of diesel equivalents 

4. 40 CFR 600.113 

Table A-2 – Small Line-haul Locomotive Emission Factors (grams per gal) 

Small Line- Emission Factor 

Haul g/gal 

NOx 236.60 

PM10 5.82 

CO2 10,180 

Uncontrolled yard locomotive emission factors were obtained from EPA's Locomotive Emission 

Factors (2009). 

Table A-3 – Yard Locomotive Emission Factors (grams per gal) 

Yard 

Emission Factor 

g/gal 

NOx 264.48 

PM10 6.69 

CO2 10,180 

Uncontrolled yard locomotive emission factors were obtained from EPA's Locomotive Emission 

Factors (2009). All emission factors listed here reflect uncontrolled (i.e., pre-Tier 0) emission 

levels. 
 

 

 

 

 

 

 

Appendix B: Surrogate Locomotive Data 

Surrogate Data for Emission Estimation 

Data provided in the R-1 reports have been compiled and evaluated to identify useful 

surrogates that may help Partners gap-fill missing data. Because the data is from Class I 

operations, it may be biased to larger operations. 

Surrogates for Calculating Fuel Consumption 

The basic approach allows for emission calculations that roughly approximate emissions using 

reported total annual fuel consumption. If annual fuel consumption data are unknown, 

surrogate data, such as locomotive population, miles traveled, annual ton-miles or TEU-miles, 

can be used to provide an estimate for line-haul locomotive fuel consumption, as noted in the 

following table. 

Table B-1 Fuel Usage Surrogates 

Line-Haul Surrogate 

Data Options in 

Absence of Annual 

Fuel Usage 

Number of 

Locomotives 

Total Annual 

Locomotive 

Miles 

Total Annual 

Ton Miles 

Freight 

Transported 

Total Annual TEUmile Equivalents 

Multiplication Factor 

for estimating 

Annual Fuel Usage 

(gal/yr) 

132,800 

(gal/yr*locomotive) 

2.44 (gal/ 

locomotive 

miles) 

0.002 (gal/ton 

miles freight 

transported) 

0.053 

(gal/TEU-mile 

Equivalents) 

Values used to develop the surrogates were derived from the Bureau of Transportation 

Statistics 2012 National Transportation Statistics Table 4-17 

(http://www.bts.gov/publications/national_transportation_statistics/html/table_04_17.html) 

When using the basic approach to estimate yard locomotive emissions, the number of 

locomotives can be applied to the fuel consumption factors noted in the following equation to 

estimate annual fuel usage: 

Yard Fuel Use (gal/yr) = 195,451 (gal/yr*yard locomotive) x Number of Yard Locomotives 

Surrogates for Metric Comparisons 

The railroad model is designed to apply calculated emissions to a variety of operational 

parameters. This allows the derivation of metrics that can be used as a reference point to 

evaluate a Partner’s environmental performance relative to others. 
 

In instances where the necessary information has not been provided, surrogate data presented 

in Table B-2, may be used to estimate total miles traveled or the total annual ton-miles, based 

on the number of active line-hail locomotives in the Partner's fleet. 

Table B-2 Surrogates for Estimating Annual Miles and Ton-Miles 

Metric for Which 

Surrogate Data is 

Needed 

Total Annual Train 

Miles Traveled 

Total Annual 

Ton-Miles 

Multiplication Factor 

for Estimating Train 

miles or ton-miles 

based on the 

Number of 

Locomotives 

54,400 

(miles/yr*locomotive) 

63,744,000 (tonmiles/yr*locomotive) 
 

Appendix C – Derivation of National Average g/kW-hr Emission Factors 

From Argonne GREET Model Version 1 2011. 

http://greet.es.anl.gov/ 

1. Electric Generation Mix (From Annual Energy Outlook 2010) 

U.S. Mix 

Residual oil 1.0% 

Natural gas 22.9% 

Coal 46.4% 

Nuclear power 20.3% 

Biomass 0.2% 

Others 9.2% 

Biomass Type assumed = 100% forest residue 

Others = Hydro, Wind, Geothermal, Solar PV etc. 

2. Electric Transmission and Distribution Loss = 8.0% 

3. Power Plant Emissions: in Grams per kWh of Electricity Available at Power Plant Gate 

GREET-Calculated Emission Factors 

By Fuel-Type Plants (Stationary and Transportation) 

Oil-Fired NG-Fired 

CoalFired 

BiomassFired: 

Woody 

BiomassFired: 

Herbaceous 

BiomassFired: 

Forest 

Residue 

TOTAL based 

on US Mix 

NOx 

PM10 

PM2.5 

CO2 

0.833 0.578 1.058 1.169 1.169 

0.157 0.023 0.100 0.135 0.135 

0.118 0.023 0.050 0.067 0.067 

834 505 1,083 1,086 1,016 

1.169 

0.135 

0.067 

1,379 

0.634 

0.054 

0.030 

627 

CO2 in burnt biomass from atmosphere -1,086 -1,016 -1,379 

Assumes no emissions from nuclear power plants or “Others” 

4. Power Plant Emissions: Grams per kWh of Electricity Available at User Sites (wall outlets) 

Total power plant gate emissions/(1-electric transmission and distribution loss) 

Total delivered based on US 

electric generation mix 

NOx 

PM10 

PM2.5 

CO2 

0.690 

0.058 

0.033 

682