### APPENDIX 2 MOBILE Modeling Assumptions(This page intentionally left blank)

### MOBILE6.2 Modeling Results

MOBILE6.2 model runs to demonstrate complian ce for the 1997 8-hour ozone standards. Since Mecklenburg and Gaston Counties were 1-hour ozone maintenance areas, the performance standards for these two counties were slightly different from the remaining counties in the 1997 8-hour ozone nonattainment area (Cabarrus, Li ncoln, Rowan, Union Counties and Coddle Creek and Davidson Townships in Iredell County). Below are the emission factors for the two performance standards that are required to be met and the pr ogram target based upon how North Carolina’s Inspection and Maintenance (I/M) pr ogram is actual run. The North Carolina I/M program meets the emission reduc tion targets in the attainment year. The State of North Carolina commits to meeting the performance standard. Emission Factors for Mecklenburg and Gaston Counties (grams/mile) VOC NOx

Performance Standard 0.784 0.750 Program Target 0.726 0.688

Emission Factors for Remaining Counties (grams/mile) VOC NOx

Performance Standard 1.363 1.027 Program Target 1.280 0.936

### MOBILE6.2 Modeling Assumptions

Modeled Calendar Year:

• As required by the Code of Federal Regul ations (CFR) 40 CFR 51.352(e) the evaluation date is to be set at six years after the effective date of designation. The CharlotteGastonia-Rock Hill, North Carolina-South Carolina Moderate Nonattainment area (referred to as the Metrolin a area) has an effective de signated date of June 15, 2004, therefore, the evalua tion date is 2010. I/M Program Start Year:

• Performance Standards for Mecklenburg a nd Gaston Counties: According to 51.352(c), the required start date wa s 2002, with the idle test fo r 1968 to 1995 vehicles and On Board Diagnostic II (OBD) fo r 1996 and newer vehicles.

• Program Target for Mecklenburg and Gaston Counties: Although these two counties had the idle test implemented in prior to 2002, the OBD I/M program was implemented in these two counties starting July 2002 for all 1996 and newer vehicles. By the evaluation year (2010), the idle test had been phased-out and only the OBD test was required. Therefore, the I/M program start year fo r Mecklenburg and Gaston Counties was set at 2003.

• Performance Standards for Remaining Countie s: According to 51.352(e), the required start date was 2008, with the id le test for 1968 to 2000 vehicles and On Board Diagnostic II (OBD) for 2001 and newer vehicles.

• Program Target for Cabarrus and Union Counties: Although these two counties had the idle test implemented in prior to 2002, th e OBD I/M program was implemented in these two counties starting July 2002 for all 1996 and newer vehicles. By the evaluation year (2010), the idle test had been phased-out and on ly the OBD test was required. Therefore, the I/M program start year for Cabarr us and Union Counties was set at 2003.

• Program Target for Iredell, Lincoln and Ro wan Counties: The OBD I/M program, for all 1996 and newer vehicles, was implemented in Iredell and Rowan C ounties starting July 2003 and in Lincoln County star ting January 2004. Therefore, the I/M program start year for Cabarrus and Union Counties was set at 2003. Anti-Tampering Program:

• North Carolina began a statewide safety inspection program in 1975. This program includes checking the vehicle for tampering of emission control equipment. Vehicles 35 years old and newe r are inspected. Vehicle Registra tion and VMT mix:

• North Carolina Division of Air Quality (NCDAQ ) receives vehicle registration data for Mecklenburg and Gaston Counties combined and for the remaining counties in that nonattainment area uses the statewide ve hicle registration data. The 2008 vehicle registration data, the most rece nt data available, was used for these runs. The vehicle registration data is attached at the end of this summary.• The VMT mix was based on the latest data ava ilable from the transportation partners and is presented below.

0.3751 0.0939 0.3127 0.0963 0.0443 0.0388 0.0037 0.0031 0.0024 0.0086 0.0021 0.0023 0.0082 0.0019 0.0010 0.0056

Vehicle Speeds:

• To minimize the number of runs as recomm ended by the United States Environmental Protection Agency (USEPA), one vehicle sp eed of 24 miles per hour was used for all

runs. Reid Vapor Pressure:

• For Mecklenburg and Gaston Counties, the Re id Vapor Pressure (RVP) is 7.8 pounds per square inch (psi) during the summer months as required by 40 CFR 80.27.

• For the remaining nonattainment counties, th e RVP is 9.0 psi during the summer months. Temperature, Relative Humidity and Barometric Pressure:

• The temperature, relative humidity and barometric pressure used in these modeling runs were the same data used in the latest attain ment demonstration plan. This data was based on average July 2002 data for the Metrolina region.

• The hourly temperature data as formatted in the input files:

71.0 73.8 77.0 80.3 82.5 85.4 87.3 88.5 89.1 88.5 89.6 89.2 86.3 82.6 77.8 77.5 76.2 75.9 75.0 74.0 73.2 82.3 71.6 71.0

• The hourly relative humidity data as formatted in the input files:

91. 86. 78. 71. 65. 59. 53. 50. 48. 51. 47. 47. 53. 61. 70. 71. 76. 77. 79. 83. 85. 87. 88. 91.

• The barometric pressure is set to 30 inches of mercury, which is consistent with the average summertime barometric pressure in North Carolina.

Altitude:

• North Carolina is considered a low a ltitude region for modeling purposes.*Convert MOBILE5 Registration Fractions to MOBILE6-Based Registration Fractions

* *Calendar Year: 2008.000User-Input

* *MOBILE5b Reg Fractions * 0.081 0.081 0.076 0.077 0.076 0.073 0.070 0.065 0.067 0.059 * 0.049 0.043 0.034 0.034 0.025 0.020 0.015 0.011 0.009 0.007 * 0.005 0.004 0.003 0.002 0.015 * 0.042 0.058 0.063 0.055 0.063 0.059 0.060 0.064 0.065 0.061 * 0.054 0.050 0.039 0.040 0.038 0.026 0.019 0.016 0.015 0.017 * 0.015 0.013 0.012 0.008 0.049 * 0.122 0.153 0.111 0.094 0.079 0.059 0.042 0.050 0.053 0.051 * 0.035 0.035 0.018 0.024 0.012 0.011 0.005 0.005 0.005 0.006 * 0.005 0.004 0.002 0.003 0.018 * 0.101 0.109 0.136 0.094 0.077 0.074 0.044 0.053 0.062 0.052 * 0.025 0.036 0.017 0.020 0.012 0.007 0.007 0.005 0.006 0.007 * 0.006 0.006 0.005 0.004 0.034 * 0.061 0.051 0.097 0.068 0.045 0.057 0.053 0.050 0.050 0.045 * 0.031 0.026 0.034 0.034 0.019 0.024 0.023 0.013 0.012 0.010 * 0.013 0.022 0.026 0.034 0.101 * 0.040 0.046 0.100 0.078 0.078 0.076 0.065 0.070 0.061 0.085 * 0.023 0.052 0.039 0.035 0.028 0.021 0.013 0.011 0.014 0.006 * 0.007 0.007 0.008 0.006 0.031 * 0.062 0.114 0.108 0.105 0.076 0.058 0.051 0.066 0.073 0.068 * 0.035 0.042 0.024 0.030 0.015 0.011 0.007 0.010 0.011 0.008 * 0.006 0.005 0.003 0.003 0.005 * 0.088 0.123 0.107 0.094 0.069 0.077 0.059 0.053 0.047 0.040 * 0.032 0.024 0.021 0.020 0.014 0.014 0.010 0.007 0.005 0.006 * 0.005 0.006 0.009 0.008 0.060

*

* * MOBILE6 Vehicle Classes: * 1 LDV Light-Duty Vehicles (Passenger Cars) * 2 LDT1 Light-Duty Trucks 1 (0-6,000 lbs. GVWR, 0-3750 lbs. LVW) * 3 LDT2 Light Duty Trucks 2 (0-6,000 lbs. GVWR, 3751-5750 lbs. LVW) * 4 LDT3 Light Duty Trucks 3 (6,001-8500 lbs. GVWR, 0-3750 lbs. LVW) * 5 LDT4 Light Duty Trucks 4 (6,001-8500 lbs. GVWR, 3751-5750 lbs. LVW) * 6 HDV2B Class 2b Heavy Duty Vehicles (8501-10,000 lbs. GVWR) * 7 HDV3 Class 3 Heavy Duty Vehicles (10,001-14,000 lbs. GVWR) * 8 HDV4 Class 4 Heavy Duty Vehicles (14,001-16,000 lbs. GVWR) * 9 HDV5 Class 5 Heavy Duty Vehicles (16,001-19,500 lbs. GVWR) * 10 HDV6 Class 6 Heavy Duty Vehicles (19,501-26,000 lbs. GVWR)* 11 HDV7 Class 7 Heavy Duty Vehicles (26,001-33,000 lbs. GVWR) * 12 HDV8A Class 8a Heavy Duty Vehicles (33,001-60,000 lbs. GVWR) * 13 HDV8B Class 8b Heavy Duty Vehicles (>60,000 lbs. GVWR) * 14 HDBS School Busses * 15 HDBT Transit and Urban Busses * 16 MC Motorcycles (All)

* REG DIST * RESULTING MOBILE6-BASED REGISTRATION FRACTIONS

* *MOBILE6 REGISTRATION FRACTIONS BY VEHICLE CLASS AND AGE * LDV M5 LDGV 1 0.081 0.081 0.076 0.077 0.076 0.073 0.070 0.065 0.067 0.059 0.049 0.043 0.034 0.034 0.025 0.020 0.015 0.011 0.009 0.007 0.005 0.004 0.003 0.002 0.015 * LDT1 M5 LDGT1 2 0.042 0.058 0.063 0.055 0.063 0.059 0.060 0.064 0.065 0.061 0.054 0.050 0.039 0.040 0.038 0.026 0.019 0.016 0.015 0.017 0.015 0.013 0.012 0.008 0.049 * LDT2 M5 LDGT1 3 0.042 0.058 0.063 0.055 0.063 0.059 0.060 0.064 0.065 0.061 0.054 0.050 0.039 0.040 0.038 0.026 0.019 0.016 0.015 0.017 0.015 0.013 0.012 0.008 0.049 * LDT3 M5 LDGT2 4 0.122 0.153 0.111 0.094 0.079 0.059 0.042 0.050 0.053 0.051 0.035 0.035 0.018 0.024 0.012 0.011 0.005 0.005 0.005 0.006 0.005 0.004 0.002 0.003 0.018 * LDT4 M5 LDGT2 5 0.122 0.153 0.111 0.094 0.079 0.059 0.042 0.050 0.053 0.051 0.035 0.035 0.018 0.024 0.012 0.011 0.005 0.005 0.005 0.006 0.005 0.004 0.002 0.003 0.018 * HDV2B M5 HDVs (Combined HDGV and HDDV) 6 0.082 0.112 0.122 0.099 0.077 0.066 0.048 0.060 0.067 0.060 0.030 0.039 0.021 0.025 0.013 0.009 0.007 0.008 0.009 0.008 0.006 0.006 0.004 0.004 0.019 * HDV3 M5 HDVs (Combined HDGV and HDDV) 7 0.082 0.112 0.122 0.099 0.077 0.066 0.048 0.060 0.067 0.060 0.030 0.039 0.021 0.025 0.013 0.009 0.007 0.008 0.009 0.008 0.006 0.006 0.004 0.004 0.019 * HDV4 M5 HDVs (Combined HDGV and HDDV) 8 0.082 0.112 0.122 0.099 0.077 0.066 0.048 0.060 0.067 0.060 0.030 0.039 0.021 0.025 0.013 0.009 0.007 0.008 0.009 0.0080.006 0.006 0.004 0.004 0.019 * HDV5 M5 HDVs (Combined HDGV and HDDV) 9 0.082 0.112 0.122 0.099 0.077 0.066 0.048 0.060 0.067 0.060 0.030 0.039 0.021 0.025 0.013 0.009 0.007 0.008 0.009 0.008 0.006 0.006 0.004 0.004 0.019 * HDV6 M5 HDVs (Combined HDGV and HDDV) 10 0.082 0.112 0.122 0.099 0.077 0.066 0.048 0.060 0.067 0.060 0.030 0.039 0.021 0.025 0.013 0.009 0.007 0.008 0.009 0.008 0.006 0.006 0.004 0.004 0.019 * HDV7 M5 HDVs (Combined HDGV and HDDV) 11 0.082 0.112 0.122 0.099 0.077 0.066 0.048 0.060 0.067 0.060 0.030 0.039 0.021 0.025 0.013 0.009 0.007 0.008 0.009 0.008 0.006 0.006 0.004 0.004 0.019 * HDV8a M5 HDVs (Combined HDGV and HDDV) 12 0.082 0.112 0.122 0.099 0.077 0.066 0.048 0.060 0.067 0.060 0.030 0.039 0.021 0.025 0.013 0.009 0.007 0.008 0.009 0.008 0.006 0.006 0.004 0.004 0.019 * HDV8b M5 HDVs (Combined HDGV and HDDV) 13 0.082 0.112 0.122 0.099 0.077 0.066 0.048 0.060 0.067 0.060 0.030 0.039 0.021 0.025 0.013 0.009 0.007 0.008 0.009 0.008 0.006 0.006 0.004 0.004 0.019 * HDBS M5 HDVs (Combined HDGV and HDDV) 14 0.082 0.112 0.122 0.099 0.077 0.066 0.048 0.060 0.067 0.060 0.030 0.039 0.021 0.025 0.013 0.009 0.007 0.008 0.009 0.008 0.006 0.006 0.004 0.004 0.019 * HDBT M5 HDDVs 15 0.062 0.114 0.108 0.105 0.076 0.058 0.051 0.066 0.073 0.068 0.035 0.042 0.024 0.030 0.015 0.011 0.007 0.010 0.011 0.008 0.006 0.005 0.003 0.003 0.005 * Motorcycles M5 MC 16 0.088 0.123 0.107 0.094 0.069 0.077 0.059 0.053 0.047 0.040 0.032 0.024 0.021 0.020 0.014 0.014 0.010 0.007 0.005 0.006 0.005 0.006 0.009 0.008 0.060*Convert MOBILE5 Registration Fractions to MOBILE6-Based Registration Fractions

* *Calendar Year: 2008.000User-Input

* *MOBILE5b Reg Fractions * 0.046 0.062 0.061 0.067 0.065 0.063 0.063 0.061 0.067 0.062 * 0.054 0.050 0.042 0.045 0.035 0.029 0.023 0.018 0.015 0.013 * 0.010 0.008 0.006 0.005 0.031 * 0.025 0.037 0.040 0.042 0.052 0.048 0.048 0.052 0.057 0.054 * 0.052 0.052 0.041 0.046 0.048 0.034 0.027 0.024 0.023 0.028 * 0.026 0.022 0.021 0.015 0.083 * 0.051 0.075 0.074 0.067 0.071 0.056 0.045 0.050 0.056 0.051 * 0.040 0.044 0.032 0.041 0.030 0.022 0.016 0.014 0.017 0.021 * 0.018 0.012 0.014 0.010 0.072 * 0.042 0.049 0.057 0.050 0.052 0.047 0.039 0.048 0.052 0.046 * 0.032 0.038 0.031 0.039 0.028 0.020 0.018 0.016 0.019 0.024 * 0.023 0.018 0.020 0.016 0.177 * 0.031 0.038 0.101 0.079 0.058 0.060 0.063 0.056 0.058 0.043 * 0.030 0.024 0.028 0.025 0.016 0.016 0.013 0.019 0.014 0.012 * 0.010 0.023 0.033 0.037 0.111 * 0.032 0.046 0.083 0.069 0.080 0.078 0.066 0.075 0.060 0.078 * 0.020 0.058 0.040 0.031 0.025 0.020 0.014 0.012 0.014 0.013 * 0.009 0.009 0.013 0.011 0.044 * 0.046 0.080 0.087 0.077 0.064 0.056 0.046 0.063 0.071 0.072 * 0.039 0.049 0.034 0.036 0.026 0.019 0.013 0.015 0.020 0.018 * 0.018 0.014 0.009 0.008 0.019 * 0.077 0.107 0.097 0.085 0.067 0.077 0.064 0.055 0.048 0.041 * 0.031 0.027 0.026 0.020 0.017 0.014 0.009 0.007 0.007 0.007 * 0.007 0.008 0.013 0.011 0.078

*

* * MOBILE6 Vehicle Classes: * 1 LDV Light-Duty Vehicles (Passenger Cars) * 2 LDT1 Light-Duty Trucks 1 (0-6,000 lbs. GVWR, 0-3750 lbs. LVW) * 3 LDT2 Light Duty Trucks 2 (0-6,000 lbs. GVWR, 3751-5750 lbs. LVW) * 4 LDT3 Light Duty Trucks 3 (6,001-8500 lbs. GVWR, 0-3750 lbs. LVW) * 5 LDT4 Light Duty Trucks 4 (6,001-8500 lbs. GVWR, 3751-5750 lbs. LVW) * 6 HDV2B Class 2b Heavy Duty Vehicles (8501-10,000 lbs. GVWR) * 7 HDV3 Class 3 Heavy Duty Vehicles (10,001-14,000 lbs. GVWR) * 8 HDV4 Class 4 Heavy Duty Vehicles (14,001-16,000 lbs. GVWR) * 9 HDV5 Class 5 Heavy Duty Vehicles (16,001-19,500 lbs. GVWR) * 10 HDV6 Class 6 Heavy Duty Vehicles (19,501-26,000 lbs. GVWR)* 11 HDV7 Class 7 Heavy Duty Vehicles (26,001-33,000 lbs. GVWR) * 12 HDV8A Class 8a Heavy Duty Vehicles (33,001-60,000 lbs. GVWR) * 13 HDV8B Class 8b Heavy Duty Vehicles (>60,000 lbs. GVWR) * 14 HDBS School Busses * 15 HDBT Transit and Urban Busses * 16 MC Motorcycles (All)

* REG DIST * RESULTING MOBILE6-BASED REGISTRATION FRACTIONS

* *MOBILE6 REGISTRATION FRACTIONS BY VEHICLE CLASS AND AGE * LDV M5 LDGV 1 0.046 0.062 0.061 0.067 0.065 0.063 0.063 0.061 0.067 0.062 0.054 0.050 0.042 0.045 0.035 0.029 0.023 0.018 0.015 0.013 0.010 0.008 0.006 0.005 0.031 * LDT1 M5 LDGT1 2 0.025 0.037 0.040 0.042 0.052 0.048 0.048 0.052 0.057 0.054 0.052 0.052 0.041 0.046 0.048 0.034 0.027 0.024 0.023 0.028 0.026 0.022 0.021 0.015 0.083 * LDT2 M5 LDGT1 3 0.025 0.037 0.040 0.042 0.052 0.048 0.048 0.052 0.057 0.054 0.052 0.052 0.041 0.046 0.048 0.034 0.027 0.024 0.023 0.028 0.026 0.022 0.021 0.015 0.083 * LDT3 M5 LDGT2 4 0.051 0.075 0.074 0.067 0.071 0.056 0.045 0.050 0.056 0.051 0.040 0.044 0.032 0.041 0.030 0.022 0.016 0.014 0.017 0.021 0.018 0.012 0.014 0.010 0.072 * LDT4 M5 LDGT2 5 0.051 0.075 0.074 0.067 0.071 0.056 0.045 0.050 0.056 0.051 0.040 0.044 0.032 0.041 0.030 0.022 0.016 0.014 0.017 0.021 0.018 0.012 0.014 0.010 0.072 * HDV2B M5 HDVs (Combined HDGV and HDDV) 6 0.044 0.065 0.072 0.064 0.058 0.052 0.043 0.056 0.062 0.059 0.036 0.044 0.033 0.037 0.027 0.020 0.015 0.015 0.019 0.021 0.020 0.016 0.015 0.012 0.097 * HDV3 M5 HDVs (Combined HDGV and HDDV) 7 0.044 0.065 0.072 0.064 0.058 0.052 0.043 0.056 0.062 0.059 0.036 0.044 0.033 0.037 0.027 0.020 0.015 0.015 0.019 0.021 0.020 0.016 0.015 0.012 0.097 * HDV4 M5 HDVs (Combined HDGV and HDDV) 8 0.044 0.065 0.072 0.064 0.058 0.052 0.043 0.056 0.062 0.059 0.036 0.044 0.033 0.037 0.027 0.020 0.015 0.015 0.019 0.0210.020 0.016 0.015 0.012 0.097 * HDV5 M5 HDVs (Combined HDGV and HDDV) 9 0.044 0.065 0.072 0.064 0.058 0.052 0.043 0.056 0.062 0.059 0.036 0.044 0.033 0.037 0.027 0.020 0.015 0.015 0.019 0.021 0.020 0.016 0.015 0.012 0.097 * HDV6 M5 HDVs (Combined HDGV and HDDV) 10 0.044 0.065 0.072 0.064 0.058 0.052 0.043 0.056 0.062 0.059 0.036 0.044 0.033 0.037 0.027 0.020 0.015 0.015 0.019 0.021 0.020 0.016 0.015 0.012 0.097 * HDV7 M5 HDVs (Combined HDGV and HDDV) 11 0.044 0.065 0.072 0.064 0.058 0.052 0.043 0.056 0.062 0.059 0.036 0.044 0.033 0.037 0.027 0.020 0.015 0.015 0.019 0.021 0.020 0.016 0.015 0.012 0.097 * HDV8a M5 HDVs (Combined HDGV and HDDV) 12 0.044 0.065 0.072 0.064 0.058 0.052 0.043 0.056 0.062 0.059 0.036 0.044 0.033 0.037 0.027 0.020 0.015 0.015 0.019 0.021 0.020 0.016 0.015 0.012 0.097 * HDV8b M5 HDVs (Combined HDGV and HDDV) 13 0.044 0.065 0.072 0.064 0.058 0.052 0.043 0.056 0.062 0.059 0.036 0.044 0.033 0.037 0.027 0.020 0.015 0.015 0.019 0.021 0.020 0.016 0.015 0.012 0.097 * HDBS M5 HDVs (Combined HDGV and HDDV) 14 0.044 0.065 0.072 0.064 0.058 0.052 0.043 0.056 0.062 0.059 0.036 0.044 0.033 0.037 0.027 0.020 0.015 0.015 0.019 0.021 0.020 0.016 0.015 0.012 0.097 * HDBT M5 HDDVs 15 0.046 0.080 0.087 0.077 0.064 0.056 0.046 0.063 0.071 0.072 0.039 0.049 0.034 0.036 0.026 0.019 0.013 0.015 0.020 0.018 0.018 0.014 0.009 0.008 0.019 * Motorcycles M5 MC 16 0.077 0.107 0.097 0.085 0.067 0.077 0.064 0.055 0.048 0.041 0.031 0.027 0.026 0.020 0.017 0.014 0.009 0.007 0.007 0.007 0.007 0.008 0.013 0.011 0.078