# APPENDIX E

**Philadelphia , PA portion of the Philadelphia** **** **Wilmington, PA -** **NJ -** **DE Nonattainment Area:**  **Emissions Inventory for the PM** **2.5** 

# NAAQS **Technical Support Document Mobile Source Highway Emissions Inventory** 

**Executive Summary**

**July 200**  **9 Prepared for:**  Mobile Sources Section, Bureau of Air Quality Pennsylvania Department of Environmental Protection

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

### Philadelphia**, PA portion of the Philadelphia -** **Wilmington, PA -** **NJ -** **DE Nonattainment**  **Area : Mobile Source Emissions Inventory** 

**Executive Summary** July 200 9 

# Table of Contents
**INTRODUCTION ................................**  **................................ ................................**  **................................ .......................**  **1** METHODOLOGY ................................ ................................ ................................ ................................ ......................... 1 INVENTORY S UBMISSION MATERIALS ................................ ................................ ................................ ....................... 2 **DATA SOURCES AND ANA LYSIS TOOLS**  **................................ ................................**  **................................ ...........**  **3** A NALYS IS T OOLS ................................ ................................ ................................ ................................ ...................... 3 TRAFFIC D ATA S OURCE/F LEET DATA INPUTS ................................ ................................ ................................ ........... 4 TRAFFIC GROWTH A SSUMPTIONS ................................ ................................ ................................ .............................. 4 I/M AND FUEL P ARAMETERS ................................ ................................ ................................ ................................ ..... 6 WEATHER D ATA ................................ ................................ ................................ ................................ ........................ 7 O THER INPUTS ................................ ................................ ................................ ................................ ........................... 8 **RESOURCES ................................**  **................................ ................................**  **................................ ...............................**  **9** 

# List of Tables
T ABLE 1: S UMMARY OF APPENDICES ................................ ................................ ................................ ............................ 2 T AB LE 2: S UMMARY OF INVENTORY ANALYSIS T OOL S ................................ ................................ ................................ 3 T ABLE 3: P HILADELPHIA , PA PORTION OF NONATTAINMENT AREA VMT GROWTH A SSUMPTIONS ............................. 6



# Summaryof Appendices
**A pp**  **endix E -**  **1:** Mobile Source Highway Emissions Inventory

– An Explanation of Methodology **Appendix E -** **2:** Philadelphia , PA Portion of Nonattainment Area PM 2. 5 Emissions Results

(By Year, Functional Class and Vehicle Type) **Appendix E -** **3:** MOBILE6.2 Input Parameter Summary **Appendix E -** **4:** MOBILE6.2 Sample Input Files **Appendix E -**  **5:** Traffic Grow th Forecasting System

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## INTRODUCTION This technical document supports the PM 2.5 State Implementation Plan (SIP) for the Philadelphia, PA portion of the nonattainment area (Bucks County, Chester County, Delaware County, Montgomery County and Philadelphia County), Pennsylvania
. To meet the emission inventory requirements of section 172(c)(3) of the Clean Air Act , a regional mobile source highway inventory has been prepared for direct and pre cursor PM 2.5 emissions. The pollutants included in the inventory are primary emissions (including condensibles) of PM 2.5 , PM 10 and the precursor emissions of VOC, CO, NOx, SO 2 , and NH 3 . This document provides the 2002 base year and 2 009 projections of mobile (highway) vehicle miles of travel (VMT) and annual PM 2.5 direct and precursor emissions that are needed to satisfy the SIP requirements. The following sections summarize the methodology and data inputs used to produce the mobile emissions inventory. 

## M **ethodology** Guidance documents from EPA have been used to develop the base and future year emissions inventories for the Philadelphia, PA portion of nonattainment area . They include:

 Guidance for Creating Annual On
-Road Mobile Source Emission Inventories for PM2.5 Nonattainment Areas for Use in SIPs and Conformity , US EPA Office of Transportation and Air Quality, dated August , 200 5 .  User’s Guide to MOBILE 6.1 and MOBILE6.2, Mobile Source Emission Factor Model, EPA420 -R- 02 - 028, date d August 200 3 .  Technical Guidance on the Use of MOBILE6.2 for Emission Inventory Preparation , US EPA Office of Air and Radiation, and Office of Transportation and Air Quality, dated August 2004. Mobile source emission factors have been calculated using EPA’s MOBILE6.2 emission model. The methodologies used to produce the emission results conform to the recommendations provided in the above guidance documents
. A mix 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 For this submission, the 2002 base year emission estimates are consistent with past analyses and submissions utilizing 2002 traffic and environmental data. Future year estimates for 2009 are based on the latest available 2005 traffic data, PENNDOT growth rates, and environmental parameters . Current assumptions are used for control strategies (e.g. Inspection
-Maintenance , Pennsylvania Clean Vehicle

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programs ) and fuel characteristics. The analysis methodology is consistent with past statewide inventory efforts including the 200 5 National Emissions Inventory (NEI) submission. Annual VMT and emissions are produced using a sum of 12 monthly analysis scenarios. A detailed methodology is provided in **Appendix E**  **- 1**  . Detai led information on the Commonwealth’s Traffic Growth Forecasting System is provided in **Appendix E**  **- 5**  . The following sections address the key input data sources and analysis tools used for the preparation of the emissions inventory. 

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

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

Emissions Inventory

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

**E -** **2** Philadelphia, PA portion

of Nonattainment Area PM 2.5 Emission Results (By Year, Functional Class and Vehicle Type) Provides county by functional class and county by vehicle type annual emission tables for 2002 and 2009 . **E -** **3** 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. **E -** **4** MOBILE6.2 Sample

Input File Provides examples of the MOBILE6.2 input files. **E -**  **5** Traffic Growth

Forecasting System Provides detailed explanation of the Commonwealth’s revised methodology for VMT forecasting based on socioeconomic and demographic projections.

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## DA **TA SOURCES**  **AND ANAL**  **YSIS TOOLS**  This section provides a summary of the key input data and analysis tools used for producing the regional emis sions inventory. The key elements to the modeling protocol are described in the sections below. A more detailed description of the analysis process and tools is provided in the methodology report in **Appendix E**  **- 1**  **and E -**  **5** . 

## Analysis Tools The inventory 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 direct PM 2.5 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 Custom SCC Output Reformatting Program Prepares output database files by EPA’s Source Classification Codes (SCC) The inventory reflects the highway mobile source emission estimations using EPA’s MOBILE6.2 emission model , which accounts for changes in vehicle technology and regulations
. MOBILE6 .2 is a software application program that provides estimates of current and future emissions from highway motor vehicles. All states other than California must use MOBILE6.2 for the development of SIP and conformity emission analyses. The model can estimate both direct particulate matter emissions and the emissions of certain particulate precursors for cars, trucks, buses, and motorcycles. 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. Custom programs have also been prepared to translate the VMT and emission results into a database file indexed by EPA’s Source Classification Code (SCC). This code represents combinations of vehicle type groupings, functional classes, and time periods.

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## Traffic Data Source/Fleet Data Inputs The PENNDOT Roadway Management System (RMS) data serves as the primary highway data source for the county and functional class VMT estimates. The data source is used to provide a “snapshot” of the regional roadway system and volumes in 2002 and 2005 . The data includes the average annual daily traffi c (AADT) 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 and 2005 VMT totals are adjusted to match the annual HPMS VMT totals reported to FHWA. Annual VMT and emission results are based on a MOBILE6.2 analysis for an average day in each of the 12 months. These results are then expanded to monthly sub
-totals and then to an annual total. The daily and monthly seasonal factors , used to adj ust the AAD T traffic volumes, are developed from data contained in the document, 2005 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 2 00 5 traffic counts taken at permanent and in
-pavement ATR (automatic traffic recorder) locations throughout the state. The factors are used to adjust AADT volumes to an average day in each month, and the PPSUITE software calculates unique congested speeds for each roadway segment
. 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 2005 Pennsylvania Traffic Data report are used to determine the temporal variations of future year traffic volumes. Vehicle mix patterns are calculated for each county / functional class grouping utilizing a combination of 2002/2 00 5 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 E**  **** **1** . The distribution of vehicles to fuel type (diesel, gas) i s 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 16 composite MOBILE6 vehicle types. 2 002 and 2005 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 forecasting plays a pivotal role in estimating future year emissions for each Pennsylvania county and region. The expected volume of traffic, measured in vehicle miles of travel (VMT), needs to be estimated for each county, or group of counties , for each relevant future year. This becomes the basis for further disaggregation of VMT to the roadway types on which the miles are expected to occur, vehicle types and vehicle age. This PM 2.5 inventory utilizes a VMT growth rate projection methodology developed by PENNDOT as documented in the report “Statistical Evaluation of Projected Traffic Growth, Traffic Growth Forecasting System: Final Report, March 14, 2005”. As part of that study, a statewide traffic growth forecasting system was developed that incorporates traffic data from PENNDOT’s Traffic Information System and

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available socioeconomic forecasts. The study methodology has been shared among PENNDOT, DEP, and other interagency c onsultation group members, including the Pennsylvania Air Quality Work Group (which includes EPA, FHWA, and representatives from larger PA Metropolitan Planning Organizations (MPOs), and approved by PENNDOT. The methodology contains the following improvements over past statewide forecasting approaches:

 Strong statistical basis and consistent with state of the art.  Thorough documentation of approach vs. alternatives.  Increased data robustness through the inclusion of both county
-level historical traffic trends from the PENNDOT Roadway Management System (RMS) databases (the basis for VMT reporting to the Federal Highway Administration of USDOT through the Highway Performanc e Monitoring System (HPMS) and county-based demographic projections from an independent 3 rd party (Woods and Poole Economics, Inc.).  Expedient and inexpensive update process. The data inputs to the traffic growth forecasting system are periodically updated to produce revised forecast growth factors for each county in the state. The frequency of this update is at least every 5 years, consistent with EPA and FHWA “Latest Planning Assumptions” guidance. The most recent available forecasts, used in the development of this inventory, include historic HPMS VMT through 2005 and use of the 2006 State Profile , developed by Woods & Poole Economics. The 2006 State Profile includes historical demographic data and forecasts by year from 1969 through 2030 for every county and Metropolitan Statistical Area (MSA) in Pennsylvania
. The county VMT forecast growth rates are developed for four functional classifications in each county: urban interstate, urban noninterstate, rural interstate and rural non-interstate. The PENNDOT statistical VMT forecasting model incorporates historical VMT trends, socio and economic data (households, mean household income), and a relative measure of transportation capacity (lane miles per capita). The forecasts used for this annual PM 2 .5 emissions inventory have been developed to account for potential variability in future regional VMT growth. Va riability from the base forecast may be caused by multiple factors which influence vehicle travel, many or most of which may be influenced by outside factors or events. The county
-level growth rates from the PENNDOT VMT forecasting system have been evaluated to determine an overall regional growth rate for the nonattainment area. Growth rates were examined for counties within the nonattainment area and for nearby counties that might impact future conditions within the region. **Table 3**  summarizes the assumed projected growth of VMT for future analysis years within the nonattainment area.

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**Table 3**  **: Philadelphia** **, PA**  **P ortion of**  **Nonattainment Area**  **VMT Growth Assumptions**

**Analysis Year**  **Total Growth**

**From 2002 Annualized Growth** 

**From Previous Analysis Year**  **Bucks County**  2002 ----- ----- 2009 15.6 % 2.2 %

**Chester County**  2002 ----- ----- 2009 15.6 % 2.2 %

**Delaware Count** **y** 2002 ----- ----- 2009 18.9 % 2.7 %

**Montgomery County**  2002 ----- ----- 2009 16.5 % 2.4 %

**Philadelphia County** 2002 ----- ----- 2009 17.7 % 2.5 %


## I/M and Fuel Parameters The Inspection Maintenance (I/M) program inputs to the MOBILE6.2 model are based on past and current programs within the Philadelphia area. Pennsylvania’s first inspection and maintenance (I/M) program was implemented in 1984 which required applicable vehicles to undergo an annual one - speed idle test. This basic I/M program applied to model
year 1975 - 198 0 gasoline cars and light duty trucks up to 9,000 pounds GVW registered in the 5 -county Philadelphia region (Bucks , Chester, Delaware, Montgomery and Philadelphia counties) and the 4
-county Pittsburgh metropolitan region (Allegheny, Beaver, Washington and Westmoreland counties). In October 1997, Pennsylvania began an enhanced I/M Program to include ASM 5015 tailpipe testing, two - speed idling test, gas cap and visual anti
-tempering inspection. M odel
-year 1981 and newer cars and light duty trucks registered in the above nine counties in the Philadelphia and Pittsburgh regions are subject to the enhanced I/M Program
. New model years are exempt for the first year. The Commonwealth’s 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

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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 re gistration determines which inspections are required. The 2002 I/M program inputs to the MOBILE6 model for the 5
-county Philadelphia region include a PA97 with ASM I/M program and phase
-in cutpoints. The I/M program parameters include: **Model Years Pro**  **gram Parameters** 1981 & newer ASM5015 with Phase
-in 1975 & newer Gas Cap 1975

– 1980 Idle 1975 & newer ATP The 2009 I/M program inputs to the MOBILE6 model for the Philadelphia region include a PAOBDII and PA97 with ASM I/M program and final cutpoints. The I/M program parameters include: **Model Years Program Parameters**  1996 & newer PAOBDII Gas Cap 1981

– 1995 ASM 5015 F inal 1975

– 1995 Gas Cap 1975 & newer ATP The RVP values , varying by month, 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 E -** **3** . 

## Weather Data Updated weather information has been obtained from the National Climatic Data Center to calculate the minimum and maximum tem peratures and absolute humidity data inputs to the MOBILE6.2 model. These assumptions are consistent with the 200 5 NEI inventory submission
. Average minimum and maximum temperatures and barometric pressure values for each month were obtained for each of the weather station locations in Pennsylvania. In addition, average relative humidity values were obtained for 6 -hour intervals (4 intervals during a 24 day period) for each of the 12 months . Absolute humidity values by month were then calculated from the rel ative humidity, barometric pressure , and temperature for each of the 4 daily intervals using EPA’s M6HUMID program. The lowest of these 4 values for each month is determined to be the absolute humidity for that month. Other weather data required by MOBILE6.2 are assumed as the program defaults. These include the cloud cover, peak sun, and sunrise/sunset options.

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## O**ther Inputs** Federal Programs Federal vehicle emissions control and fuel programs are incorporated into the MOBILE6.2 software. The pro grams 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. State Programs The MOBILE6.2 software also allows for modeling of permissible state activities control emissions from highway vehicles. In 1998 , Pennsylvania promulgated the New Motor Vehicle Emissions Control Program. This program created the Pennsylvania Clean Vehicles Program that 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. As a compliance alternative to the Pennsylvania Clean Vehicles Program, automakers have elected to comply with the National Low Emission Vehicle (NLEV) program. The NLEV program began phase
-in starting in model year 1999 . The Pennsylvania rules allow the NLEV compliance option for the duration of Pennsylvania’s participation in the NLEV program. Pennsylvania is in the process of amending the Pennsylvania Clean Vehicles Program to initiate in model year 2008. As a result, the modeling results assume a 2008 start year for the Pennsylvania Clean Vehicles Program. Benefits from this program are realized in 2008 and beyond. The methodology employed to estimate the benefits of adopting CA LEV II emissions standards is consistent with the approach provided in the EPA’s Ju ne 2002 Guidance (

Modeling Alternative NLEV Implementation and Adoption of California Standards in MO BILE6, June 5, 2002)
. The approach assumes:
 Tier2 phase
-in schedule consistent with MOBILE6.2 defaults  LEVII phase
-in schedule as provided in EPA’s June 2002 Guidance  Assumes PZEV and AT -PZEV vehicles share the same evaporative emissions as LEVII/Tier2 vehicles **Appendix E**  **- 4**  contains the modified MOBILE6.2 files used to model the above assumptions. They are consistent with the June 2002 EPA guidance. The federal Tier 2 / Low Sulfur Fuel Program took effect in 2004 and in practicality supplanted the NLEV program for new light
-duty vehicles.

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## RESOURCES
Guidance for Creating Annual On
-Road Mobile Source Emission Inventories for PM2.5 Nonattainment Areas for Use in SIPs and Conformity , US EPA Office of Transportation and Air Quality, dated August, 2005. Consolidated Emissions Reporting, Federal Register, June 10, 2002 2005 Pennsylvania Traffic Data, PennDOT Bureau of Planning and Research, 200 5 . User’s Guide to MOBILE6.1 and MOBILE6.2 , Mobile Source Emission Factor Model, EPA420
-R- 02 - 028, dated August 2003 . Technical Guidance on the Use of MOBILE6 for Emission Inventory Preparation , US EPA Office of Transportation and Air Quality, August 2004 . 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 . Technical Guidance on the Use of MOBILE6.2 for Emission Inventory Preparation , US EPA Office of Air and Radiation, and Office of Transportation and Air Quality, August 2004. Statistical Evaluation of Projected Traffic Growth, Traffic Growth Forecasting System: Final Report, Michael Baker Jr., Inc., March 14, 2005.