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Sample Methodologies for Regional Emissions Analysis in Small Urban and Rural Areas

Figure 1: MOBILE6 Speed Correction Factors for Freeways (Tier 1 vehicles)

This table is from Final Facility Specific Speed Correction Factors, published in 2001 and available at http://www.epa.gov/otaq/models/mobile6/r01060.pdf. Page 3 of Final Facility Specific Speed Correction Factors states "Table 16 contains the MOBILE6 speed correction factors for freeways." Tier I Vehicles are not specifically mentioned.

Speed Correction Factors For Freeways By Emission Level*
Avg. Speed (mph) Total Hydrocarbons (THC) Carbon Monoxide (CO) Oxides of Nitrogen (NOx) Non-Methane HC (NMHC)
Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Level 1 Level 2 Level 3
7.1 2.71 2.65 2.15 1.73 1.61 2.19 2.26 1.81 1.50 2.87 2.75 2.14
10 1.71 1.71 1.63 1.29 1.27 1.52 1.40 1.28 1.18 1.69 1.73 1.62
15 1.08 1.10 1.20 1.02 1.04 1.08 0.94 0.98 1.00 1.00 1.09 1.20
19.6 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
20 1.00 0.99 0.99 1.00 1.00 0.99 1.00 1.00 1.00 1.00 0.99 0.99
25 0.95 0.93 0.86 0.99 0.97 0.94 1.04 1.01 1.00 1.00 0.94 0.86
30 0.91 0.88 0.77 0.98 0.95 0.91 1.07 1.02 1.00 1.00 0.90 0.77
35 0.91 0.81 0.68 1.00 0.98 0.87 1.07 1.02 1.00 1.07 0.83 0.68
40 0.97 0.77 0.64 1.12 1.06 0.87 1.14 1.04 1.00 1.20 0.79 0.64
45 1.04 0.73 0.61 1.24 1.14 0.87 1.21 1.07 1.00 1.32 0.74 0.61
50 1.10 0.69 0.57 1.36 1.21 0.87 1.28 1.09 1.00 1.45 0.70 0.57
55 1.17 0.65 0.54 1.47 1.29 0.86 1.35 1.12 1.00 1.57 0.66 0.54
60 1.24 0.61 0.50 1.59 1.37 0.86 1.42 1.15 1.01 1.70 0.62 0.50
65 1.30 0.57 0.47 1.71 1.45 0.86 1.49 1.17 1.02 1.82 0.58 0.47

* Emission levels shown as Fwy emissions in Table 14. See Section 4.6.

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Updated: 6/28/2017
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