DRAFT

Diesel Emissions Quantifier

User's Guide

U.S. Environmental Protection Agency

Ariel Rios Building

1200 Pennsylvania Avenue, N.W.

Washington, DC 20460

August 23, 2007

Table of Contents

1.  Introduction. 1
2.  Screen-Specific Instructions. 2
2.1  Start Screen. 2
2.2  Fleet Information Screen. 3
2.2.1  Enter New Vehicle Group Information. 4
2.2.2  Apply a Technology to New Vehicle Group. 6
2.2.3  Save a New Vehicle Group and Technology. 8
2.2.4  Save a Scenario. 9
2.2.5  Edit Data. 9
2.2.5.1  Edit Vehicle Group Information. 9
2.2.5.2  Edit Technology Information. 9
2.2.6  Calculate Results. 10
3.  Emissions Results Screen. 10
3.1  Annual, Daily Results. 11
3.2  Lifetime Results. 12
3.3  Preview/Download Data. 12
Appendix A:  Dropdown List Options. A- 1
Appendix B:  Quantifier Calculations. B- 1
I.  Overview.. B- 1
II.  Symbols. B- 1
III.  Inputs. B- 1
IV.  Conversion Factors and Constants. B- 2
V.  Results Calculations. B- 3
A.  Daily/Annual Emissions Results Calculations. B- 3
B.  Lifetime Emissions Results Calculations. B- 6
VI.  Special Cases. B- 7
A.  Vehicle and Engine Replacement Strategies. B- 7
B.  Trailer Strategies. B- 8
Appendix C:  Scrappage Rate Tables. C- 1

List of Tables

Table 1  Annual, Daily, and Lifetime Emission Results. 11
Table A-1  Vehicle Types and Associated Sectors. A- 1
Table A-2  Sectors and Associated Vehicle/Equipment A- 1
Table A-3  Horsepower Options. A- 5
Table A-4  Fuel Types. A- 6
Table A-5  Retrofit Technology Types and Associated Technologies. A- 7
Table C-1  On-Highway Scrappage Table:   Scrappage Table Survival Fraction
(Based on 1980 Vehicles) C- 1
Table C-2  Nonroad Median Life Table. C- 3
Table C-3  Nonroad Default Scrappage Curve. C- 5

DRAFT

Diesel Emissions Quantifier

User's Guide

1.  Introduction

The Diesel Emissions Quantifier ("the Quantifier") is a tool that enables users to estimate emissions from a fleet of diesel vehicles and/or equipment.  The Quantifier can calculate emissions estimates of NO_x, PM, HC, CO, and CO₂ for highway and Nonroad vehicles that utilize various emissions control technologies. 

The Quantifier has been modeled after the National Mobile Inventory Model (NMIM).  The NMIM is an application developed by the EPA to determine estimates of current and future emission inventories for on-road motor vehicles and Nonroad equipment.  The Quantifier is a web-based interface that asks users intuitive questions to help estimate their emissions. 

The Quantifier is capable of the following:

1.   Calculating emissions from a single emissions reduction project;

2.   Comparing fleet emissions using different retrofit control technologies; and

3.   Assisting SmartWay carrier partners and grantees in developing proper data reports for submission to the EPA. 

            The Quantifier calculates the following quantities for the fleet's baseline emissions for one year, and for the lifetime of a fleet:  emissions reduced by the use of control technologies, and the cost effectiveness of control technologies.  The calculated results may then be downloaded.  

            The following SIP and conformity language appears on each screen of the Quantifier:

"The Diesel Emission Quantifier should not be used for the calculation of any emission reductions to be incorporated in a State Implementation Plan (SIP) or conformity determination, and certain other technical applications.  Please do not continue to use the Quantifier until you have read the important usage information." 

The "important usage information" hyperlink takes users to the Disclaimer screen, where the following text is displayed:  

"The Diesel Emissions Quantifier is intended as a helpful tool to prepare estimates, but is not designed to meet requirements under other types of air or transportation submissions.  Please do not continue using the Quantifier until you have read the important usage information below.

●    The Diesel Emission Quantifier should not be used for the calculation of any emission reductions to be incorporated in a State Implementation Plan (SIP) or conformity determination.

●    If you wish to calculate emission reductions for a SIP or conformity determination, you should review the appropriate SIP and conformity guidance document and consult with your EPA Regional Office.

●    For long-duration idle reduction, the SIP and conformity guidance can be found in the document Guidance for Quantifying and Using Long Duration Truck Idling Emission Reductions in State Implementation Plans and Transportation Conformity (January, 2004, EPA420-B-04-001, PDF, 33 pages, 379K, About PDF).

●    For retrofit projects, the SIP and conformity guidance can be found in the document Diesel Retrofits:  Quantifying and Using Their Benefits in SIPs and Conformity (June, 2006, EPA420-B-06-005, PDF, 69 pages, 530K, About PDF).

●    For emission reduction strategies not covered by those guidance documents, please consult with your EPA Regional Office."

2.  Screen-Specific Instructions

2.1  Start Screen

At the Start screen of the Quantifier, users have the option to log in by entering their email address and password.  Logging in enables the user to store scenario information so that it can be retrieved at a later time.  To obtain a login and password, the user must click on the "Create a password" link.  This link takes the user to the registration screen, where contact information is entered.  Required contact information includes the user's email address, chosen password, contact name, organization name, and phone number.  The user can opt to enter additional contact information including their position and address.  When the registration information is saved, the user is taken back to the Start screen.  The "Reset password" option takes the user to another screen where they are prompted to enter their email address.  An email will be sent to the user which contains an internet link where the user can change their password.  To log out at any time, the user can click on the "Log out" link at the top of each screen. 

Users are then prompted to select the appropriate scenario that describes how they wish to use the Quantifier, select the state in which the majority of the emissions benefits will be gained, and can optionally input contact information.  

When selecting a scenario, the user has the following options:

1.   "quantifying emissions?":  This option allows the user to calculate emissions for a project.  This option can also be used when reporting the emissions reduction of a project. 

2. "preparing data for the EPA? (contact information required)":  This option must be selected for all Quantifier users who want to download data from the application. 

If the user logs in, and has previously logged in and saved scenarios, the following option will appear for each saved scenario:  "returning to work on saved scenario #:  Scenario Name." 

Next, the user will select a state from the dropdown list.  The user should select the state where the project is located.  If the project spans across more than one state, select the state that will yield the majority of the emissions reduction benefits.  The user does not need to select a state if they are returning to a saved scenario.

When the user selects the "preparing data" option, a contact information section will appear below the state dropdown list.  All fields in the Required Contact Information section must be completed by all users who select the "preparing data" option.  Users who want to download data to use in an EPA grant application only need to complete the Required Contact Information fields.  In addition to the Required Contact Information section, existing SmartWay partners are required to complete the SmartWay Carrier Questionnaire which appears below the Optional Contact Information section when the "Click here if you are a SmartWay Carrier/Partner" hyperlink is clicked on.  Users who are joining the SmartWay partnership for the first time are requested to complete the fields in the Required and Optional Contact Information sections, and the SmartWay Carrier questionnaire.  The questionnaire contains the following information:  

●    Does the data represents the user's initial fleet baseline, action plan, or annual update?

●    Average payload.

●    The number of straight trucks, tractors, and trailers that are owned, leased, and subcontracted.

●    The percentage of the fleet operating in each of the following modes:  

--   Truckload;

--   Less than Truckload;

--   Pickup/Delivery;

--   Leasing; and

--   Other. 

●    The user's parent company and subsidiaries (if applicable). 

The questionnaire can be hidden by clicking on the "Click here if you are not a SmartWay Carrier/Partner" hyperlink which appears at the top of the questionnaire.  Once finished, the user can click Continue to move to the next screen to input specific information on the fleet. 

2.2  Fleet Information Screen

            On this screen, the user will input information specific to each vehicle group in the fleet, as well as the vehicles to which one or more emission reduction strategies are applied.  This includes the types of vehicles in the fleet, the number, model year, and retrofit year of each vehicle group; fuel and usage information; the type(s) of technology applied; and cost information.  This screen must be completed for each vehicle group separately.  The user is encouraged to input fleet data with as much detail as possible; there is no limit to the number of vehicle groups that can be entered for a fleet.  For example, a user has a fleet of 100 school buses with a range of model years from 1990 to 2005.  The user may enter this fleet as one entry using an average model year.  Alternatively, the user may enter vehicles of each model year separately.  The more accurate the data entered is, the more accurate the results will be.

2.2.1  Enter New Vehicle Group Information

The Enter New Vehicle Group Information section of the Fleet Information screen is where the user enters information on each vehicle group in the fleet.  The following fields appear in the order listed below, and must be completed or selected from dropdown lists.  All of the dropdown list options are provided in Appendix A.  Numeric values must be entered without commas.

State:  The state selected on the Start Screen will appear as the Selected State. 

Type:  Select the vehicle type (either On-Highway or Nonroad) for the vehicle group from the dropdown list. 

Sector:  Select the vehicle group sector from the dropdown list.  The list options will vary depending on the Type selected.  The Quantifier will be expanded to include Marine and Barge applications in the future.

Vehicle or Equipment:  Select the Vehicle/Equipment category from the dropdown list.  The list options vary depending on the Sector selected.

Quantity:  Enter the number of the vehicles of the fleet in a specific vehicle group.

Model Year:  Enter the model year of the engine, not the vehicle.

Retrofit Year:  Enter the year the emissions control retrofit will be installed.

Horsepower:  If the user selects Nonroad as the Type, a field for Horsepower will appear below the Retrofit Year field.  The user must select the vehicle's horsepower from the dropdown list.  If the Horsepower dropdown list does not include an exact match for the user's vehicle, the user should select the nearest value.

In the following fields, the user must provide information on how the vehicles in a particular vehicle group are operated.  This includes information on fuel usage, distance traveled, travel time, and idling time.  There is a direct correlation between fuel usage and CO₂ emissions.  Different fuels emit different amounts of CO₂ based on their chemical make-up.

Fuel Type:  Select the fuel used by the vehicle group from the dropdown list.  Table A-4 lists the options that appear in the Fuel Type dropdown list, their associated CO₂ factors, and the vehicle types and years for which each fuel type can be selected.  The CO₂ factors are multiplied by the fuel volume to convert a non-diesel fuel volume into a diesel equivalent.  The resulting value will be displayed in the "Calculated Fuel Volume" field. 

Fuel Volume:  Fuel Volume is the amount of fuel used (in gallons per year) by all vehicles in a group.  A Fuel Type must be selected before the user can enter Fuel Volume.  Depending on which Fuel Type is selected, the user-entered Fuel Volume is translated into a diesel equivalent in the field below.  This allows the CO₂ emissions to be compared on an equal basis across the entire fleet. 

Vehicle Miles Traveled (VMT):  This field will only appear if "On-Highway" is selected as the Type.  If "Nonroad" is selected as the Type, a Usage Rate field will appear instead.  VMT is the average number of miles traveled per vehicle in the group per year.  VMT can be calculated by averaging the miles traveled per year of all vehicles in a group.  Alternatively, VMT can be
calculated by dividing the total miles traveled in a year by the total number of vehicles in the group.  The example below illustrates this calculation: 

      Example:

            VMT = (10,000 + 20,000 + 30,000 miles/year)/3 vehicles = 20,000 miles/vehicle/year 

Usage Rate:  This field will only appear if "Nonroad" is selected as the Type.  The Usage Rate is the average number of hours of use per vehicle per year.  It is calculated by averaging the number of hours of use per year of all vehicles in a group.  Alternatively, Usage Rate can be calculated by dividing the total hours of use by all vehicles in a group in one year by the number of vehicles in the group.  An example of this calculation is provided below:

Example:

            Usage Rate = (500 + 1,000 + 1,200 hours/year)/3 vehicles = 900 hours/vehicle/year

Idling hours (including hours saved):  The Idling Hours field only appears for On-Highway vehicles.  This is the average number of hours spent idling per vehicle per year including any hours diverted (saved) using an idling control strategy.  The Quantifier calculates On-Highway emissions based on two modes:  drive and idle.  In order to show proper savings the Quantifier needs information based on the true number of hours diverted (saved) using the control strategy or it will take emissions from the drive mode.  Idling hours can be calculated by averaging the idling hours of each vehicle in a group, or by adding the idling hours of all vehicles in a group, and dividing this sum by the number of vehicles.  This is to include hours that have been diverted through idling control measures.

Funding Data (Click here to enter funding information.):  Entering funding data is optional, but if the user wants to view the Total Cost Effectiveness of a project, funding data are required.  The user can click on the "Click here to enter funding information" hyperlink and a list of funding sources and fields for dollar amounts will appear.  The user should enter funding amounts in the appropriate fields.  Funding data includes all costs associated with a project, including retrofit capital costs, installation costs, administrative costs, etc. 

Total Project Cost:  This quantity is the sum of all funding source amounts entered by the user.  The Quantifier automatically calculates this value. 

2.2.2  Apply a Technology to New Vehicle Group

            In the Apply a Technology to New Vehicle Group section of the Fleet Information screen, the user enters information on the emission control technologies that are to be applied to the vehicle group.  The following fields appear in the order listed below, and must be completed or selected from dropdown lists.  All of the dropdown list options are provided in Appendix A.

Technology Type:  The Technology Type is an emissions control category.  The Technology Type is selected from the dropdown list. 

Technology:  Technology is a specific emissions control method that is selected from the dropdown list.  When multiple technologies are applied to a single vehicle, the following rules and restrictions apply:

●    Engine Replacement/Repower -- only one technology may be applied to a vehicle.

●    Hybrids -- only one technology may be applied to a vehicle.

●    Emission Control Devices -- only one technology may be applied to a vehicle.

●    Engine and Truck Upgrades -- only one technology may be applied to a vehicle.

●    Trailer Strategies -- only one technology may be applied to a vehicle.

●    Aerodynamic Devices -- multiple selections may be applied to a vehicle.

●    Tire Technology -- only one technology may be applied to a vehicle.

●    Weight Reduction -- only one technology may be applied to a vehicle.

●    Fuel Options -- only one technology may be applied to a vehicle.

●    Advanced Lubricant Technology Strategies -- only one technology may be applied to a vehicle.

●    Speed Management Policies -- only one technology may be applied to a vehicle.

●    Idling Control Strategies -- multiple selections may be applied to a vehicle.  Note that the idling hours reduced for all selections must not exceed the total idling hours which were inputted under the vehicle group section.

The following technology combinations are not allowed:

New Model Year:  This field will only appear if the Engine Replacement/Repower technology type is selected.  This New Model Year is the model year of the new or retrofitted engine.

Idling Hours Reduced:  If Idling Control Strategies are selected as the Technology Type, the Idling Hours Reduced field appears.  The user should enter the number of idling hours reduced by implementing the selected Technology.  The number of idling hours reduced cannot exceed the number of idling hours entered for the vehicle group.

Apply Technology To:  Enter the number of vehicles to which this technology applies.  This number can be all or a portion of the Quantity entered previously for the entire vehicle group.  As the user adds technologies, this section will expand to list out each group of vehicles to which technologies have been applied.  For example, if technology 1 is applied to 20 out of 100 vehicles, the following two lines will appear:

●    Apply to ___ vehicles (out of 20) that currently have Technology 1; and

●    Apply to ___ vehicles (out of 80) that do not currently have a technology.

Pollutants Table:  Once the Technology Type and Technology are selected, the percent emissions reductions for NO_x, PM, HC, CO, and CO₂ will automatically populate the Pollutants table.  The percent reductions are average values specific to the selected technology.  Note that for Idling Control Strategies, the percent reductions are based on the engine being used in idling mode only.  If the user knows the exact percent reductions for the specific technology they have selected, then they can manually change the values that appear in the table.  The maximum percentage a user can enter is 100%.  It is recommended that users only make changes if they have more accurate values from the manufacturer.  The following disclaimer appears below the "Installation Cost" field and applies to the pollutants table:

            "Note that the percent reduction associated with a particular retrofit technology or cleaner fuel may vary by manufacturer and application and may change as more information becomes available.  Please refer to EPA's verified technology web page for the latest detailed information on verified emission reductions from retrofit technologies.  Some of the technologies listed here are not yet verified by EPA or the California Air Resources Board (CARB).  Emissions reductions calculated by this model based on user-entered percent reductions not based on EPA or CARB's verified technology list should not be used for any official purposes or to meet any reporting requirements.  Emission reductions calculated by this model based on user-entered percent reductions not based on EPA or CARB's verified technology list should not be used for any official purposes or to meet any reporting requirements."

EPA's verified technology web page is http://www.epa.gov/otaq/retrofit/retroverifiedlist.htm.

Unit Cost:  The cost to maintain and operate one vehicle.  The user must enter a non-negative numeric value.  The Quantifier uses this value to calculate Capital Cost Effectiveness.

Installation Cost:  The cost to install the selected emission control technology on one vehicle.  The user must enter a non-negative numeric value.  The Quantifier uses this value to calculate Capital Cost Effectiveness.

2.2.3  Save a New Vehicle Group and Technology

Once all the required vehicle group fields are complete, the user can save the information by clicking the "Save" button, or the "Save and Add Another" button under "Vehicle Group Actions" to add additional vehicle groups.  If the user would like to clear the data entered on the screen without saving it, the "Go Back to Start" hyperlink at the top of the screen must be clicked.  From the Start Screen, the user can click "Continue" to return to the Fleet Information screen. 

To save control technology information, the user must click the "Save to V#" button under "Technology Actions."  Once at least one vehicle group is saved, the user can edit the group, add technologies, add additional vehicle groups, or proceed to the Results page.  

2.2.4  Save a Scenario

At any time, the user can save a scenario by entering a Scenario name and clicking on the "Save Scenario" button at the bottom of the screen.  The user is allowed to save a maximum of three scenarios at a time.  The user can open any previously saved scenario by clicking on the "Open a different scenario" button.  This button takes the user to another screen where they can elect to load or delete any of their saved scenarios.  The user can also opt to start working on a new scenario.  The buttons that correspond to these options are "Load," "Delete" and "New." 

2.2.5  Edit Data

            Once the user has entered and saved a complete set of data for one or more vehicle groups, the "Current Vehicles and Applied Technologies" table at the bottom of the screen will be populated.  This table lists all saved vehicle groups and their associated emissions control technologies.  Each vehicle group and technology is assigned a number in this table (e.g., V1 for the first vehicle group entered, and T1 for the first technology entered).  The user can edit or delete any group, and delete any technology by clicking the "Edit" or "Delete" buttons.  After a vehicle group and technology are saved, the green header bars on the screen will automatically change to reflect that the screen is now in editing mode, and the numbers assigned to the vehicle group and technology that can be edited are displayed.  

If at any time the user would like to clear the data entered on the screen without saving it, the "Go back to Start" hyperlink at the top of the screen must be clicked.  From the Start Screen, the user can click on the "Continue" button to return to the Fleet Information screen.  The "Jump to Current Vehicle Group Listing" hyperlink at the top of the screen takes the user to the "Current Vehicles and Applied Technologies" table at the bottom of the screen. 

 

2.2.5.1  Edit Vehicle Group Information

Once a vehicle group is saved, the user can only edit the Fuel Type and the fields that appear below Fuel Type.  The State, Type, Sector, Vehicle or Equipment, Quantity, Model Year, Retrofit Year, and Horsepower (for Nonroad) fields are not editable.  If the user wants to edit these fields, the vehicle group must be deleted and re-entered.  To edit a saved vehicle group, the user can click the "Edit" button that corresponds to the vehicle group in the Current Vehicles and Applied Technologies table.  The "Save V#" button must be clicked after any edits are made. 

To add an additional vehicle group, the user must click the "Add New" button. 

2.2.5.2  Edit Technology Information

To apply additional technologies to a vehicle group, the user must enter technology information and click the "Save to V#" button under "Technology Actions."  To edit a saved technology, the user must click the "Delete" button that corresponds to the technology in the Current Vehicles and Applied Technologies table, and re-enter the data.

2.2.6  Calculate Results

Once the user has finished entering data for an entire fleet, the user can click the "Quantify Emissions" button at the bottom of the screen to calculate results. 

3.  Emissions Results Screen

            When the user clicks on the "Quantify Emissions" button on the Fleet Information screen, the user will be taken to the Results screen.  The formulas used to generate the results are provided in Appendix B.

The data that appear in the Results table are an aggregation of the emissions from all vehicle groups and technologies that the user entered.  The Results table has the following format:

Table 1
Annual, Daily, and Lifetime Emission Results

3.1  Annual, Daily Results

The Annual and Daily sections of the Results table display annual baseline emissions information, and the emissions saved daily and annually by applying the user-selected control technologies.  The Baseline of Entire Fleet row displays annual emissions of NO_x, PM, HC, CO, and CO₂ without any emissions controls.  The Baseline of Vehicles Retrofitted shows the uncontrolled emissions of each of the five pollutants from only the vehicles that will be retrofitted with a control technology.  For example, if there are 100 vehicles in a fleet, and 50 vehicles are going to be retrofitted with emissions controls, then the Baseline of Entire Fleet will show the uncontrolled emissions from 100 vehicles, while the Baseline of Vehicles Retrofitted will show the uncontrolled emissions from 50 vehicles.  Both quantities are shown in units of tons/year.  Percent Reduced values are the emission reduction percentages obtained after control technologies are applied to a fleet.  Amount Reduced per Year values are the tons of pollutants reduced per year by applying controls.  These values converted to kilograms per day are displayed in the Daily section of the table.  The Diesel Equivalent of CO₂ emissions, in gallons per year, is displayed in the last column.

3.2  Lifetime Results

The Lifetime Emissions section of the Results table displays the emissions that are estimated to occur over the remaining lifetime of all vehicle groups in a fleet.  The Baseline of Entire Fleet, Baseline of Vehicles Retrofitted, Percent Reduced, and Amount Reduced values are analogous to the values in the Annual, Daily table.  The calculations used to derive these values are provided in Appendix B.  Amount Emitted after Retrofit, Entire Fleet values are the lifetime emissions, in tons, of the entire fleet after the user-selected control technologies are applied.  Amount Emitted after Retrofit, Retrofitted Vehicles values are the lifetime emissions, in tons, of only the retrofitted vehicles after the user-selected control technologies are applied.  The Diesel Equivalent of CO₂ emissions, in gallons, is displayed in the last column.

Capital Cost Effectiveness is calculated by dividing the total unit and installation costs of all retrofits in the fleet by the Amount Reduced.  These values are only calculated if the user enters unit and installation costs on the Fleet Information screen.  Total Cost Effectiveness is calculated by dividing the total cost of the retrofit project (capital costs, administrative costs, etc.) by the Amount Reduced.  These values are only calculated if the user enters funding information on the Fleet Information screen. 

The following note appears below the Lifetime emissions results:

"The lifetime results are dependent on each vehicle group's remaining life.  To determine the remaining life for each vehicle group, divide the lifetime results by the annual results using the Detailed Results tables below."

The funding data are displayed in a table below the Lifetime Emissions table. 

3.3  Preview/Download Data

Before downloading data, the user can preview the data in the Detailed Results section, which appears at the bottom of the Results screen.  The "Jump to detailed report" hyperlink at the top of the Results screen takes the user to the preview tables. 

The hyperlink "Click Here to jump to Download" at the top of the Results screen takes the user to the following hyperlinks, which appear at the bottom of the screen: 

View/Download Summary Report: This option appears if the user selected "Preparing data for the EPA?" from the Select Scenario option on the Start screen.  The user has the option to download the data in either Excel or CSV format.  CSV files can be opened by many desktop spreadsheet and database applications. 

This option allows the user to download a data file that is a condensed version of the Annual, Daily and Lifetime Results tables.  This condensed data file may be selected by users applying for EPA grant funds as part of a grant application.  This file contains the relevant information that EPA needs to review a grant application.  If the user has already received grant funds, this file can be used to report required data to the EPA.

When the user clicks on "as Microsoft Excel file" or "as CSV (comma separated values) file," a dialog box will appear on the screen that lets the user open the file or save it to disk. 

View/Download Detailed Report:  To download all the data entered in addition to the calculated data from the Results tables, the user must select the format by clicking either "as Microsoft Excel file" or "as CSV (comma separated values) file."  The downloaded data file can be submitted to the EPA.

 

Appendix A

Dropdown List Options

Table A-1
Vehicle Types and Associated Sectors

Table A-2
Sectors and Associated Vehicle/Equipment

Table A-3
Horsepower Options

Table A-4
Fuel Types

Table A-5
Retrofit Technology Types and Associated Technologies

 

Appendix B

Quantifier Calculations

I.  Overview

            This document provides a brief overview of the calculations used in computing the emissions results produced by the Diesel Emissions Quantifier.

            Equations and inputs are presented in two columns.  The parentheses following each entry denote the units of the result of computing the expression on the left.  For inputs, brackets following each entry denote whether the input is taken from the database ("[d]"), user input ("[u]"), a database default or a user input value ("[d/u]"), or embedded into business logic ("[e]").

            Textual references (e.g., "total number of vehicles in the fleet") have been replaced by symbolic equivalents (e.g., ) as defined below.

II.  Symbols

            These symbols take on different meanings depending on their parameters, or if they are constrained to a particular set of values.

             Vehicle type (one of "Nonroad" ( ) or "On-Highway" ( )) [d]

              Pollutant type (one of "CO," "CO₂", "HC", "PM", "NO_x") [d]

            Conversion factor from units s to units t [e]

M_n              Results calculation  [e]

III.  Inputs

            Calculations require several inputs, as noted below.

             Number of vehicles (veh) [u]

              Number of vehicles retrofitted with a given technology (veh) [u]

VMT         Vehicle miles traveled (mi/veh/yr) [u]

             Default usage rate (hr/veh/yr) [d]

              Actual usage rate (hr/veh/yr) [u]

            Default fuel usage rate (Rail only) (gal/veh/yr) [d]

             Actual fuel usage rate (Rail only) (gal/veh/yr) [d]

I                 Total idling hours per year (hr/veh/yr) [u]

I_R               Idling hours reduced per year (hr/veh/yr).  Used only with idling control     strategies  [u]

          Emissions for pollutant  of vehicle type  (tons/mi/mo/veh for On-Highway, tons/hr/yr/veh for Nonroad [d]

          Idling emissions for pollutant  of vehicle type (ton/hr/veh | ton/hr/veh) [d]

              Emissions reduction for pollutant  of a given technology (dimensionless) [d/u]

               Scrappage rate sum for a given vehicle's age and retrofit year.  A table of scrappage rate sums is provided in Table C-1 of Appendix C  [d]

              Diesel-equivalent fuel usage (gallons) [u]

            Unit cost for a particular emissions technology ($) [d]

             Installation cost for a particular emissions technology ($) [d]

            Total project cost ($) [u]

IV.  Conversion Factors and Constants

            Numeric literals have been replaced by their appropriate conversion factor or constant below.

  Months in a year (months/year)

Kilograms in a ton (kg/ton)

          Years in a day (years/day)

                                                Diesel-equivalent fuel emissions of pollutant  (gallons/ton) [d]

CO₂ fuel factor                                The following factors are used to convert non-diesel fuels into diesel equivalent gallons:

• LPG:  0.65
• LNG:  0.61
• CNG (lbs):  0.16
• CNG (ft³):  0.0074
• Biodiesel 100:  0.92
• Biodiesel 20:  0.985108
• Biodiesel 5:  0.996277
• Biodiesel 2:  0.998511
• E85:  0.626126

              On-Highway idling emissions factor for PM (g/hr/yr/veh)

             On-Highway idling emissions factor for NO_x (g/hr/yr/veh)

                            On-Highway idling emissions factor for CO₂ (g/hr/yr/veh)

                                           On-Highway idling emissions factor for HC (g/hr/yr/veh)

                                           On-Highway idling emissions factor for CO (g/hr/yr/veh)

V.  Results Calculations

A.  Daily/Annual Emissions Results Calculations

●    -- On-Highway fleet baseline emissions (tons/year):

      --   Non-CO₂:

      --