# Methodology for Calculating

**LEVII Program Benefits in Pennsylvania Technical Support Document** 

**March 2007 Prepared for:**  Mobile Sources Section, Bureau of Air Quality Pennsylvania Department of Environmental Protection

PO Box 8468 Harrisburg, PA 17105
- 8468 **Prepared by:** Michael Baker, Jr., Inc. 1304 Concourse Drive Linthicum, MD 21090 410 - 689 - 3400

### Methodology for Ca**lculating LEVII Program Benefits in Pennsylvania** March 2007 

# Table of Contents **INTRODUCTION ................................**  **................................ ................................**  **................................ .......................**  **1** EMISSION C ALCULATION METHODOLOGY ................................ ................................ ................................ ................. 1 METHODOLOGY FOR E STIMATING LEVII P ROGRAM CREDIT S ................................ ................................ .................. 3 INVENTORY S UBMISSION MATERIALS ................................ ................................ ................................ ....................... 3 **EM ISSION DATA SOURCE**  **S AND ANALYSIS TOOLS ................................**  **................................ ......................**  **4** A NALYS IS T OOLS ................................ ................................ ................................ ................................ ...................... 4 TRAFFIC D ATA S OURCE/F LEET D ATA INPUTS ................................ ................................ ................................ ........... 4 TRAFFIC GROWTH A SSUMPTIONS ................................ ................................ ................................ .............................. 5 I/M AND FUEL P ARAMETERS ................................ ................................ ................................ ................................ ..... 5 WEATHER D ATA ................................ ................................ ................................ ................................ ........................ 5 O THER INPUTS ................................ ................................ ................................ ................................ ........................... 6 **ESTIMATING LEVII PRO GRAM CREDITS**  **................................ ................................**  **................................ ........**  **6** S UMMARY OF T ECHNICAL D ATA F ILES ................................ ................................ ................................ ..................... 7 C ALCULATION OF LEVII P ROGRAM B ENEFITS ................................ ................................ ................................ .......... 8 **RESOURCES ................................**  **................................ ................................**  **................................ ...............................**  **9** 

# List of Tables T ABLE 1: S UMMARY OF APPENDICES ................................ ................................ ................................ ............................ 3 T ABLE 2: S UMMARY OF INVENTORY ANALYSIS T OOL S ................................ ................................ ................................ 4 T ABLE 3: LEVII T ECHNICAL D ATA INPUT F ILES ................................ ................................ ................................ ........... 7 T ABLE 4: IMPACT OF THE P ENNSYLVANIA C LEAN VEHICLES P ROGRAM VS F EDERAL T IER2 P ROGRAM ........................ 8



# Summaryof Appendices **App endix 1:**  Mobile Source Highway Emissions Inventory

– An Explanation of Methodology **Appendix 2:** MOBILE6.2 Input Parameter Summary **Appendix 3:** MOBILE6.2 LEVII Technical Data Input Files **Appendix 4:** Sam

ple MOBILE6.2 Input File **Appendix 5:** Ozone Modeling Results and LEVII Benefits

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## INTRODUCTION In 1998, Pennsylvania promulgated the New Motor Vehicle Emissions Control Program (25 Pa. Code Chapter 126, Subchapter D). This program created the Pennsylvania Clean Vehicles (PCV) Program that beginning in model year (MY) 2006 required new light
- duty highway motor vehicles offered for sale within Pennsylvania to be certified by the California Air Resources Board (CARB) under that Board’s Low Emitting Vehicle (LEV) program. The Pennsylvania Clean Vehicles Program does not require the California Zero Emitting Vehicle (ZEV) requirement. In December 2006, Pennsylvania promulgated amendments to the PCV program that:

 Postponed the compliance date from MY 2006 to MY 2008,  Updated program definitions in 25 Pa. Code Chapter 121, § 121.1 (relating to definitions),  Makes program regulatory clarifications, and  Provides a transition mechanism for compliance with the program. This document provides estimates of the potential LEVII program benefits within the state and summarizes the methodology used to calculate emissions. The document provides future year projections of mobile (highway) vehicle miles of travel (VMT) and emissions (ozone precursors VOC and NOx) for the years 2010, 2015, 2020, and 2025. 

## Em **ission Calculati on Methodology**  Technical guidance documents from EPA were used in the development of base and future year emissions inventories to support the analyses of potential LEVII program benefits in Pennsylvania. They include:

 Policy Guidance on the Use of M OBILE6 for SIP Development ad Transportation Conformity, US EPA Office of Air and Radiation, dated January 18, 2002.  Technical Guidance on the Use of MOBILE6 for Emission Inventory Preparation , US EPA Office of Air and Radiation, and Office of Transportation and Air Quality, dated January 2002, revised February 2, 2005.  User’s Guide to MOBILE 6.1 and MOBILE6.2, Mobile Source Emission Factor Model, EPA420 - R- 02 - 028, dated October 2002. Mobile source emission factors were calculated using EPA’s MOBILE6.2 emis sion model. The methodologies used to produce the emission results conform to the recommendations provided in EPA’s Technical Guidance. Amix of local data and national default (internal to MOBILE6.2) data has been used for this submission. Local data has been used for the primary data items that have a significant impact on emissions. These include:

 VMT and speeds  Vehicle type mixes  Vehicle age distributions  Hourly distributions  Tem peratures/humidity  Inspection/Maintenance parameters  Fuel program characteristics.

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For this analysis, local data inputs reflect the latest planning assumptions at the time of the analysis (based on 2002 data). These include current assumptions on control strategies (e.g. Inspection
Maintenance programs) and fuel characteristics. The analysis methodology is consistent with the 2002 National Emissions Inventory (NEI) submission. A detailed methodology is provided in **Appendix 1** .

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## Methodology for Estimating LEVII Program **Credits** The emission benefits of the Pennsylvania Clean Vehicles Program have been calculated using the assumptions and data files documented in EPA’s June 5, 2002 guidance entitled, “ Modeling Alternative NLEV Implementation and Adoption of California Standards in MOBILE6” and the ‘ Technical Guidan ce on the Use of MOBILE6 for Emissions Inventory Preparation” . Several key revisions to the EPA guidance assumptions were needed to reflect the program to be implemented in Pennsylvania. The revisions include the removal of the zero - emitting exhaust vehic le (ZEV) component of the program and a revised phase
-in start date of 2008 (EPA guidance assumptions are based on a 2004 start date). 

## Inventory Subm **ission Materials** To complement this document, attachments have been provided with additional detail regarding the analysis methodology, the MOBILE6.2 input parameters, and the output emission results for the counties in Pennsylvania. These include: 

### Table **1 : Summary of Appendices**  **Appendix Title**  **Description 1**  Mobile Source Highway

Emissions Inventory

– An Explanation of Methodology Provides summary of methodology used to calculate the VMT and emissions. **2** MOBILE6.2 Input

Parameter Summary Provides summary of input parameters related to traffic data sources, fuel, weather, I/M, and other MOBILE6.2

related parameters. **3** MOBILE6.2 LEVII

Input Files Provides phase
-in percentages and exhaust certification bin standards used to reflect LEVII program **4** MOBILE6.2 Sample

Input File Provides example of MOBILE6.2 input files. **5** Pennsylvania ozone

(VOC, NOx) Emission Results (By County, Year) Provides county emissions for a summer weekday in 2010, 2015, 2020, 2025 (Results included for 2004, 2006, 2009 LEVII start date)

(2008 start date results interpolated)

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## EMISSION DA

**TA SOUR** **CES AND**  **ANAL YSIS**  **TOOLS** This section provides a summary of the input data and analysis tools used to evaluate the potential emission benefits of the Pennsylvania Clean Vehicles Program. The key elements to the modeling protocol are described in the secti ons below. Amore detailed description of the analysis process and tools is provided in the methodology report in **Appendix 1** . 

## Analysis Tools The statewide emissions analysis utilizes several key software/programs for producing the county emissions totals. These tools are outlined in **Table 2** .



### Table **2 : Summary of Inventory Analysis Tools**  **Tool Purpose**  MOBILE6.2 Produces emission factors for each pollutant in grams/mile for VOC and NOx PPSUITE Processes the highway data, Calculates hourly

congested speeds for each state roadway segment, Prepares MOBILE6.2 input files, Processes MOBILE6.2 output files The statewide inventory reflects the highway mobile source emission estimations using EPA’s MOBILE6.2 emission model. PPSUITE represents an enhanced version of the Post Processor for Air Quality (PPAQ) software system that has been used for previous inventory and conformity submissions in Pennsylvania. The software has undergone significant revisions to ensure consistency with the MOBILE6.2 emissions model. PPSUITE plays a key role in the development of hourly roadway speed estimates, which are supplied as input to the MOBILE6.2 model. The software is also used to prepare the MOBILE6.2 input shell and to process the MOBILE6.2 outputs. 

## Traffic Data Source/Fleet Data Inputs The 2002 PENNDOT Roadway Management System (RMS) data serves as the primary highway data source for the county and functional class VMT estimates. The data source provides a “snapshot” of the regional roadway system and volumes in 2002. The data includes the 2002 average annual daily traffic volumes for all state roadways in Pennsylvania. T o account for additional local roadway VMT and to ensure consistency with reported HPMS totals, the 2002 VMT totals are adjusted to match the 2002 HPMS VMT totals reported to FHWA. Based on the requirements for ozone inventories, traffic volumes on each RMS roadway segment must be adjusted to a summer weekday. The daily and monthly seasonal factors are developed from data contained in the document, 2002 Pennsylvania Traffic Data , as prepared by PennDOT’s Bureau of Planning and Research. The seasonal and daily factors provided in this document are based on statistical analyses of 2002 traffic counts taken at permanent and in
-pavement ATR (automatic traffic recorder) locations throughout the state. Based on these seasonal traffic volumes, the PPSUITE software calculates unique congested speeds for each roadway segment during an ozone summer weekday scenario.

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PPSUITE calculates congested speeds by hour of the day for each roadway segment and provides the information as input to the MOBILE6.2 software. T o disaggregate the daily RMS volumes to hourly volumes, auto and truck hourly pattern data from PennDOT’s 2002 Penns ylvania Traffic Data report are used to determine the temporal variations in traffic volumes. Vehicle mix patterns are calculated for each county and functional class grouping utilizing a combination of 2002 RMS truck percentages and MOBILE6.2 default vehicle mix distributions. The development of vehicle type pattern data input to the MOBILE6.2 software is described in more detail in **Appendix 1**  . The distribution of vehicles to fuel type (diesel, gas) is determined from the MOBILE6.2 default diesel sales fractions. Vehicle age distributions are input to MOBILE6.2 for each county based on registered vehicles that reflect July 1 summer conditions. These distributions reflect the percentage of vehicles in the fleet up to 25 years old and are listed by the 1 6 composite MOBILE6 vehicle types. 2 002 vehicle age distributions have been used for this inventory from the PennDOT Bureau of Motor Vehicles Registration Database. Due to insufficient data, only data for light
- duty vehicles are used as local inputs. The heavy
- duty vehicles use the internal MOBILE6.2 defaults. 

## Traffic Growth Assumptions Traffic growth forecasting plays a pivotal role in estimating future year emissions for the region. This inventory utilizes county- specific growth rates, as used for past conformity and inventory submissions, based on an extrapolation of historic HPMS VMT growth trends. The growth rates were originally shared between PennDOT, PaDEP, and other Interagency Consultation Group members, including the PA Conformity Work Group (which includes EPA, FHWA, and representatives from larger MPOs within the state). 

## I/M and Fuel Parameters The Inspection Maintenance (I/M) program inputs to the MOBILE6.2 model are based on current programs within the county. The Pennsylvania inspe ction and maintenance (I/M) program was upgraded and expanded throughout the state with a phase
-in period starting in December 2003 and fully implemented by June 2004. The program test requirements vary by region and include on-board diagnostics (OBD) technology that uses the vehicle’s computer for model years 1996 and newer to download potential engine problems that could effect emissions. The program, named PAOBDII, is implemented in the Philadelphia, Pittsburgh, and South Central / Lehigh Valley Regions. The Northern Region receives gas cap and visual inspections and the other 42 counties in the Commonwealth receive a visual inspection. Vehicles subject to the program include 1975 and newer model year gasoline cars and light duty trucks up to 9,000 pounds GVW. New model years are exempt for the first year. The county of registration determines which inspections are required. The summer weekday RVP values are consistent with values used for past inventory efforts. These assumptions, as well as the I/M program and fuel parameters, are summarized in **Appendix 2 and 4** . 

## Weather Data Weather information is based on information obtained from the National Climatic Data Center to calculate the minimum and maximum temperatures and absolute humidity data inputs to the MOBILE6.2 model. These assumptions are consistent with the 2002 NEI inventory submission.

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Other weather data required by MOBILE6.2 are assumed as the program defaults. These include the cloud cover, peak sun, and sunrise/sunset options. 

## Oth **er Inputs** Federal vehicle emissions control and fuel programs are incorporated into the MOBILE6.2 software. The programs include:

 The Federal Motor Vehicle Control Program (FMVCP) including the National Low Emission Vehicle Program (NLEV) and federal Tier II / Low Sulfur Fuel Program;  Emissions standards for medium and heavy duty vehicles in 2002, 2004 and 2007;  Stage II and Onboard Refueling Vapor Recovery (ORVR). Note: Pennsylvania considers emissions from refueling operations an area source category. While MOBILE6.2 is employed to calculate emissions factors for that source category, refueling emissions are not included in highway vehicle emissions estimations. For analyses used to determine benefits related to the Pennsylvania Clean Vehicles Program, modifications were made to the federal vehicle control assumptions in MOBILE6.2. The input parameters were revised according to EPA guidance as discussed in the following sections. 

## ESTIMA **TING LEVII PROGRAM CREDITS**  The emission benefits of the Pennsylvania Clean Vehicles Program have been calculated using the assumptions and data files documented in EPA’s June 5, 2002 guidance entitled, “ Modeling Alternative NLEV Implementation and Adoption of California Standards in MOBILE6”
. EPA’s guidance provide s key assumptions used to model the LEVII program impacts including:

 CARB LEVII phase
-in schedules  LEVII exhaust emission certification bin standards  Methods for treatment of PZEV, AT
-PZEV evaporative emissions The calculations of LEVII benefits are determined by comparisons to a base
- case, which is considered the Tier2 federal program. M OBILE6.2 assumes the default Tier2 phase
-in schedule as estimated and prepared by EPA. This phase
-in schedule is automatically applied within MOBILE6.2 applications. A ssumptions must also be made for the sales of future vehicles under California’s LEVII program. The analysis uses the CARB LEVII phase
-in percentages for passenger cars and light
-duty trucks as presented in EPA’s Ju

ne 2002 guidance (Tables A- 1 to A - 3). The phase
-in percentages are based on a 2004 program start date. S ince the Pennsylvania Clean Vehicles Program will start in 2008, alternative LEVII phase
-in percentages have been developed for these analyses. Note that Pennsylvania’s program will not include California’s ZEV mandate, thus those phase
-in assumptions are not used for the analysis. The LEVII program may include significant sales of PZEV and AT
-PZEV type vehicles. Under the ZEV mandate, such vehicles must produce “near-zero” evaporative emi ssions. A s indicated in EPA’s June 2002 Guidance, the MOBILE6 model can only produce evaporative emissions for the following conditions:

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 Zero evaporative emissions consistent with Pure ZEV vehicles  Evaporative emissions equivalent to LEVII/Tier2 vehicle s Inreality, the PZEV and AT -PZEV evaporative emissions fall somewhere between these two options. The EPA June 2002 Guidance recommends an approach that assumes that such vehicles produce evaporative emissions consistent with LEVII vehicles. 

## Summ **ar y of Technical Data Files**  EPA’s Ju ne 2002 guidance provides the key input data needed to reflect the impacts of the California LEVII program. **Table 3**  summarizes the files used for Pennsylvania’s analyses, including the revisions and modifications made to each EPA file. **Appendix 3** provides a printout of the technical data files used in the analyses. Technical data files were developed and applied for alternative LEVII program start dates including 2004, 2006, and 2009. The files provided by EPA were used directly for the 2004 program start date calculations; however, EPA’s LEVII94.D file was not used since the Pennsylvania Clean Vehicles Program does not include California’s ZEV mandate. 

### Table **3 : LEVII Technical Data Input Fil** **es MOBILE6**  **Comm and**  **EPA Guidance**

**Input Data File Description**  **Modifications for Pennsylvania Analysis** 

**T2 EXH**  **PHASE -** **IN** LEVIIPH.D CARB LEVII Phase
- in percentages by exhaust certification bin for model years 2004 -2015 Files created for alternative program start dates: 2004 start date: Use EPA file directly

– No Modification 2006 start date: Create pal2exh.06* Combination of M6 Tier2 defaults from T2EXH.D file for years 2004, 2005 and LEVII standards from LEVIIPH.D for

years 2006 and above 2009 start date: Create pal2exh.09* Combination of M6 Tier2 defaults from T2EXH.D file for years 2004 -2008 and LEVII standards from LEVIIPH.D for years 2009 and above **T2 CERT**  LEVIIST.D CARB LEVII exhaust certification bins Use EPA file directly

– No Modification

**T2 EVAP**  **PHASE -** **IN** LEVIIEVP.D CARB LEVII phase
- in percentages for evaporative standards for model years 2004 and up Files created for alternative program start dates: 2004 start date: Use EPA file directly

– No Modification 2006 start date: Create pal2evp.06* Combination of M6 Tier2 defaults from T2EVAP.D file for years 2004, 2005 and LEVII standards from LEVIIEVP.D for

years 2006 and above 2009 start date: Create pal2exh.09* Combination of M6 Tier2 defaults from T2EVAP.D file for years 2004 -2 008 and LEVII standards from LEVIIEVP.D for years 2009 and above **94+ LDG**  **IMP** LEVII94.D For model years 2004
-2025 used only to establish fraction of zero
- emitting exhaust vehicles (ZEVs) Use NLEVNE.D for all scenarios since Pennsylvania program does not have ZEV mandate * Due to difference in Tier2 and LEVII bin definitions and the need to combine into one file, phase
- in percentages

were moved to different bin numbers to ensure correct vehicle standard representation

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## Calculation of LEVII Program **Benefit s**  Analyses were conducted to identify the potential emission impacts of adopting the California LEVII program in Pennsylvania. The analyses provided in this memo focus on the ozone precursors VOC and NOx. The analyses were conducted before Pennsylvani a agreed upon the 2008 program start date and were completed for 2004, 2006 and 2009 alternative program start dates. F or this submission, 2008 LEVII emissions and benefits are determined by simple straight line interpolation between the 2006 and 2009 start date alternative runs. **Appendix 5** provides the emission tables for each alternative start date as well as the emission impacts for 2010, 2015, 2020, and 2025. **Table 4**  provides the benefits of the Pennsylvania Clean Vehicles Program (with 2008 start date and no ZEV mandate) as compared to the existing federal Tier2 program. The table illustrates emission benefits in tons/day. 

### Table **4 : Impact of the Pennsylvania Clean Vehicles Program vs Federal Tier2 Program**  **Statewide Resul** **ts 2010**  **2015 2020**  **2025**

**VOC NOx**  **VOC NOx**  **VOC NOx**  **VOC NOx**  **Emission Benefits**  **(tons/day) -**  **0.93 -**  **0.97 -** **2.74 -** **3.52 -**  **5.63 -**  **6.79 -**  **7.81 -**  **9.13**

* Negative values indicate emission benefits over Tier2 Program

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## RESOURCES Draft Emissions Inventory Guidance for Implementation of Ozone and Particulate Matter National Ambient Air Quality Standards (NAAQS) and Regional Haze Regulations , EPA, June, 2003 Consolidated Emissions Reporting, Federal Register, June 10, 2002 2002 Pennsylvania Traffic Data, PENNDOT Bureau of Planning and Research, 2002. User’s Guide to MOBILE6.1 and MOBILE6.2 , Mobile Source Emission Factor Model, EPA420
-R- 02 - 028, dated October 2002. Technical Guidance on the Use of MOBILE6 for Emission Inventory Preparation , US EPA Office of Transportation and Air Quality, January 2002. Policy Guidance on the Use of MOBILE6 for Emission Inventory Preparation , US EPA Office of Air and Radiation, January 18, 2002. Modeling Alternative NLEV Implementation and Adoption of California Standards in MOBILE6, EPA, Ju ne 5, 2002, revised February 2, 2005.