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Summary
SECTION 7.9 ENTRAINED PAVED ROAD DUST
(This page last updated on October 22, 2014)
Emission Inventory Source Category
Miscellaneous Processes / Road Dust / Paved
Entrained Road Dust
Emission Inventory Codes (EIC) |
CES Codes |
Description |
640-635-5400-0000 |
83618 |
Freeways |
640-637-5400-0000 |
83626 |
Major Streets |
640-639-5400-0000 |
83634 |
Collector Streets | 640-641-5400-0000 |
83642 |
Local Streets | 640-643-5400-0000 |
89656 |
Rural Streets | 640-636-5400-0000 |
47456 |
Unspecified Paved Roads |
Method Summary: This category includes 2008 estimates of
fugitive dust particulate matter entrained by vehicular travel on paved roads.
Road dust emissions are estimated for freeways and expressways, major streets
and highways, collector streets, local streets, rural streets and unspecified paved roads.
Vehicle exhaust, brake wear, and tire wear are computed separately as part of
the mobile source emission inventory. Activity Data Source:
County-specific vehicle miles traveled (VMT) on paved roads are from
the Air
Resources Board's on-road emission inventory model, EMFAC2011-SG and
air
districts. Caltrans' Highway Performance Monitoring System (HPMS) data
are used
to estimate the fraction of travel on freeways, major, collector and
local streets in each county. VMT for unspecified paved roads are
provided by counties or air districts.
Emission Factor Source: The
emission factor and emission factor equation used are from EPA's AP-42
document, Section 13.2.1 (Jan. 2011). California specific roadway silt loading
inputs were measured by Midwest Research Institute, University of
California, Davis, and University of California, Riverside, from
1995-1997. A default average vehicle fleet weight value of 2.4 tons is used
statewide. Western Regional Climate Center data were used to adjust emissions
for annual days of rainfall.
Temporal Data: Temporal data is the same
as is used for the on-road motor vehicle exhaust emissions because it tracks
overall vehicular activity. Daily activity has peaks at 7:00 a.m. and 4:00
p.m., with less activity at other hours. Weekly activity dips slightly on the
weekends. Monthly activity for each county/air basin/district is based on
monthly and annual days of rainfall, with decreases during the winter months.
Changes in Method and Emissions Estimates:
This update uses a revised emission factor equation from U.S EPA’s
January 2011
update to AP-42 13.2.1. The revised emission factor equation eliminates
the “C”
factor (which previously double-counted tire wear, brake wear and
exhaust emissions with
the mobile inventory), uses an updated
particle size profile and incorporates a rainfall adjustment. Activity data were updated, new
temporal profiles were developed, and the growth surrogate was revised.
Date
of Last Update: April 2014
Growth Parameter:
Emissions for all roads except unspecified roads are grown based on
changes in VMT. No growth is assumed for unspecified roads.
Statewide Emissions Summary(2008 — Annual Average Tons / Day, Uncontrolled)
EIC Code |
TOG |
CO |
NOX |
SOX |
PM10 |
640-635-5400-0000 |
0.00 |
0.00 |
0.00 |
0.00 |
29.89 |
640-637-5400-0000 |
0.00 |
0.00 |
0.00 |
0.00 |
41.24 |
640-639-5400-0000 |
0.00 |
0.00 |
0.00 |
0.00 |
9.57 |
640-641-5400-0000 |
0.00 |
0.00 |
0.00 |
0.00 |
55.76 |
640-643-5400-0000 |
0.00 |
0.00 |
0.00 |
0.00 |
25.30
|
640-636-5400-0000 |
0.00 |
0.00 |
0.00 |
0.00 |
7.26 |
Total |
0.00 |
0.00 |
0.00 |
0.00 |
169.03 |
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