EPA/Federal Highway Administration (FHWA) Near Road … · 2012. 8. 15. · EPA/Federal Highway Administration (FHWA) Near Road Collaboration Project: National Near: National Near-Road

EPA/Federal Highway Administration (FHWA) Near Road CollaborationProject: National Near-Road MSAT StudyProject: National Near-Road MSAT Study

National Association of Clean Air AgenciesAmbient Monitoring Subcommittee Meetingg gJuly 19, 2012

Sue Kimbrough1, Gayle Hagler1, Richard Baldauf1, Nealson Watkins2, Tim Hanley2, Victoria Martinez3.1U.S. Environmental Protection Agency, Office of Research and Development2U S E i t l P t ti A Offi f Ai Q lit Pl i d St d d2U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards3Federal Highway Administration

Photo image area measures 2” H x 6.93” W and can be masked by a collage strip of one, two or three images.

The photo image area is located 3.19” from left and 3.81” from top of page.

Each image used in collage should be reduced or cropped to a maximum of 2” high, stroked with a 1.5 pt white frame and positioned edge-to-edge with accompanying images.

Office of Research and DevelopmentAugust 8, 2012

Some Initial Objectives/ Science QuestionsScience Questions

• What is the spatial and temporal variability of traffic related pollutants near roadways?traffic-related pollutants near roadways?

• How do traffic (volumes, speeds, fleet mix, etc.) d i t l ( t l t h t )and environmental (meteorology, topography, etc.)

conditions affect vehicle emissions and near road air quality?y

• What tools are available, or can be produced, to identify the relationships of traffic emissions toidentify the relationships of traffic emissions to population exposures to adverse health effects for use in regulatory decision making and transportation planning?Office of Research and Development

transportation planning?1

Las Vegas study: I-15 monitoring site

Approximate Location of Site

I-15 Site

Kimbrough, S., Baldauf, R., Hagler, G., Shores, R.C., Mitchell, W., Whitaker, D.A., Croghan, C.W., Vallero, D.A., 2012. Long-term continuous

Office of Research and Development 2

measurement of near-road air pollution in Las Vegas: Seasonal variability in traffic emissions impact on local air quality. Air Quality, Atmosphere & Health.

I-15 site


Summary of continuous

Measurement ParameterSampling Approach,

Instrument Make/ModelSample

Type and Frequency

20 Meter Roadside

100 Meter Downwind

300 Meter Downwind

100 Meter

Upwind

COinfrared analyzer, Drager

X X X X continuousmeasurements conducted at each

it i it

CO2 Polytron IRX X X X

CO

nondispersive infrared, EC 9830T

X X X X

nondispersive infrared, Serinus 30

X --- --- ---

monitoring siteNOxchemiluminescence, EC

9841TX X X X

SO2pulsed fluorescence, EC

9850T--- X --- X

BCMagee Scientific –

X X X X

(5 minute)

BCAethalometer (AE 21)

X X X X

PM2.5, PM10, PM Coarsetapered element oscillating

microbalance (TEOM), Thermo--1405DF FDMS

X X X X

i RMWind Speed, Wind Direction

sonic anemometer, RM Young Model 81000

X X X X

Air Temperaturetemperature probe, Vaisala

HMP45D--- X --- ---

% Relative Humidityrelative humidity sensor,

V i l HMP45A--- X --- ---y

Vaisala HMP45A

Rain Gaugerain bucket, Ecotech Rain

Gauge--- X --- ---

Solar Radiationsolar radiation, MetOne 394

Pyranometer--- X --- ---


Sound microphone, Extech 407764 X X --- ---

Particle scattering coefficient.light scattering, Aurora 3000

(nephelometer)--- --- --- X

Summary of integratedmeasurements

Measurement Parameter

Sampling Approach, Instrument

Sample Type and Frequency

20 Meter Roadside

100 Meter Downwind

300 Meter Downwind

100 Meter

Upwind measurements conducted at each monitoring site

Make/ModelUpwind

PM2.5PM2.5 FRM method,

FRM BGI PQ20024-hour

integratedX X X X

Acetaldehyde, F ld h d

U.S.EPA Method TO-11A, Atec 2200 X X X X g

FormaldehydeCartridge Sampler

1-hour integratedAcrolein, Benzene,

1,3-Butadiene

U.S.EPA Method TO-15, Entech 1800 Canister Sampler

X X X X

1 3 B diSemi-continuous GC,

S i i1,3-Butadiene, Benzene

,Chromatotec airtoxic

866 GC

Semi-continuous (30 min.)

X X X X

Ultrafine particle

Size classification by Differential Mobility Analyzer (DMA) and Continuous p

county ( )detection by electrometer,

(15 min.)X --- X ---

TSI Model 3031200

VideoVideo, Axix 223M

and Vivotek SD7151Continuous X X --- X

and Vivotek SD7151

Particle count TSI CPC 3781 Continuous X X X X

Vehicle Count, Wavetronix radar unit

(10.525 GHz


Vehicle Speed, Vehicle Type

(frequency modulated

continuous wave (FMCW)

(15 min.) Data supplied by NDOT

Instrument performance andmethods issues

• Most instruments performed well…..exceptions…. Thermo 1405DF FDMS TEOMs (Las Vegas, lesser extent Detroit)

Design problems Manufacturing issues

TSI CPCs – Model 3781 (Las Vegas) Maintenance issues Design issues w/ orifice

Canister Samplers (Las Vegas) Tablet computers Replaced with netbooks

• Most methods worked well…..exception…. Acrolein measurements (TO-15)

Data unreliable Research task is in ORD’s Air, Climate & Energy Research Action Plan

t fi / l i


to refine/resolve issues

Las Vegas Traffic data

• I-15 supports >200,000 Average A l D il T ffi (AADT)

Average Hourly Traffic Volume Northbound/Southbound -- I-15

10,000

12,000

Annual Daily Traffic (AADT)• Truck traffic constitutes ~10%

of total volume6,000

8,000

affic

Vol

ume

2,000

4,000

Tra

Traffic Volume

Average Hourly Traffic Volume by Month Northbound/Southbound -- I-15

12,000

00 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Hour

6,000

8,000

10,000

c Vo

lum

e

Jan-09Feb-09Mar-09Apr-09May-09Jun-09J l 09

• No clear morning/ afternoon rush

2,000

4,000

Traf

fic Jul-09Aug-09Sep-09Oct-09Nov-09Dec-09

afternoon rush

• Monthly differences correspond to tourist seasons


00 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Hour

seasons

Traffic Volume = Number of Vehicles

Average hourly traffic volume and speed I-15 site from December, 2008 through December, 2009

Office of Research and Development8

Kimbrough, S., Baldauf, R., Hagler, G., Shores, R.C., Mitchell, W., Whitaker, D.A., Croghan, C.W., Vallero, D.A., 2012. Long-term continuous measurement of near-road air pollution in Las Vegas: Seasonal variability in traffic emissions impact on local air quality. Air Quality, Atmosphere & Health.

Observed wind variability

Downwind

Office of Research and Development 9Kimbrough, S., Baldauf, R., Hagler, G., Shores, R.C., Mitchell, W., Whitaker, D.A., Croghan, C.W., Vallero, D.A., 2012. Long-term continuous measurement of near-road air pollution in Las Vegas: Seasonal variability in traffic emissions impact on local air quality. Air Quality, Atmosphere & Health.

Las Vegas: concentration gradients as a function of distance from roadwayNO2

60 60

NOX

35

40

45

50

55

60

n (ppb

)

All wind directions

Winds from west

35

40

45

50

55

on (p

pb)

All wind directions

Winds from west

10

15

20

25

30

Concen

tration

10

15

20

25

30

Concen

tratio

0

5

‐100 0 100 200 300 400Distance (m)

0

5

‐100 0 100 200 300 400Distance (m)

CO BC

0.4

0.5

0.6

ppb)

All wind directions

Winds from west1.5

2.0

/m3 )

All wind directions

Winds from west

0.2

0.3

Concen

tration (p

0.5

1.0

Concen

tration (µg/

Office of Research and Development100

0.1

‐100 0 100 200 300 400Distance (m)

0.0‐100 0 100 200 300 400

Distance (m)

0 8

1.0

nsAll wind directions

Concentration

0.6

0.8

ed c

once

ntra

tion

normalized to 20 meter roadside site

0.2

0.4

Nor

mal

ize

NO2NOX COBC

for each pollutant

1.0Wind from west

0.0-100 0 100 200 300 400

Distance (m)

0.6

0.8

conc

entr

atio

ns

Pollutants exhibit

0.2

0.4

Nor

mal

ized

c

NO2NOX CO

similar spatial gradient patterns

Office of Research and Development0.0

-100 0 100 200 300 400Distance (m)

BC

11

Air pollutant concentration trends and influence of meteorological conditionsinfluence of meteorological conditions

10,0001.0

CO Concentration and Traffic Volume by Hour CO concentration trends

with increase in traffic volume (5-7 AM)

7,000

8,000

9,000

0.7

0.8

0.9volume (5-7 AM)

CO concentration appear to decrease through morning and early afternoon hours

4,000

5,000

6,000

0.4

0.5

0.6

Traf

fic V

olum

e

cent

rato

iion

(ppm

) 100 Meter Upwind20 Meter Roadside100 Meter Downwind300 Meter Downwind

CO concentrations begin to increase again beginning around 3 PM

1,000

2,000

3,000

0.1

0.2

0.3Con

c

Traffic Volume Influence of meteorological

Conditions

• Solar heating and

00.00 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

atmospheric Mixing

• Increased wind speedsHour of Day

Office of Research and Development 12Kimbrough, S., Baldauf, R., Hagler, G., Shores, R.C., Mitchell, W., Whitaker, D.A., Croghan, C.W., Vallero, D.A., 2012. Long-term continuous measurement of near-road air pollution in Las Vegas: Seasonal variability in traffic emissions impact on local air quality. Air Quality, Atmosphere & Health.

(a) (b) (c)

250

300

250

300NO2 concentration box plots highest

wind speed wind direction

0

50

100

150

200

N

0

50

100

150

200

N

box plots highest 10% of Site 1 for all wind conditions

(d) (e)

b)

80

100

00 1 2 3 4 5 6 7 8

wind speed (m/s)

0 60 120 180 240 300 360

wind direction (deg)

300 150

conditions

hr. traffic volume hour of day

Con

cent

ratio

n (p

pb

20

40

60

50

100

150

200

250

N

50

100

N

(f) (g) Distance

-100 20 100 300

C

0

200

0 3000 6000 9000 12000

hourly traffic volume

00 2 4 6 8 10 12 14 16 18 20 22

hour of day

200 200day of week month of year

100

150

200

N 100

150

200

N

y y


50

1 2 3 4 5 6 7

day of week

0

50

1 2 3 4 5 6 7 8 9 10 11 12

month of year

Polar Plot: mean concentration of NO2 by wind speed and direction.NO2 by wind speed and direction.

Highway


Integrated PM2.5 filter samples (all wind conditions)Data from mid-December 2008 to mid-December 2009

24-Hr AverageIntegrated PM 2.5 Filter Samples

25 Legend

station1

station2

t ti 3

20 Meter Roadside

100 Meter Downwind

300 Meter Downwind

15

20 station3

station4

300 Meter Downwind

100 Meter Upwind

3 )µg

/m3

10

15

PM2.

5(µ

g/m

3

5

0

c200

8n2

009

n200

9n2

009

b200

9b2

009

r200

9r2

009

r200

9r2

009

y200

9y2

009

n200

9n2

009

l200

9l2

009

l200

9g2

009

g200

9p2

009

p200

9t2

009

t200

9v2

009

v200

9c2

009

c200

9c2

009


18D

ec01

Jan

15Ja

n29

Jan

12Fe

b26

Feb

12M

ar26

Mar

09A

pr23

Apr

07M

ay21

May

04Ju

n18

Jun

02Ju

16Ju

30Ju

13A

ug27

Aug

10S

ep24

Sep

08O

ct22

Oct

05N

ov19

Nov

03D

ec17

Dec

31D

ec

Summary – Las Vegas

• Initial trends analysis suggest concentration gradients existed for gaseous pollutants and black carbon associated with traffic volume and wind speed strongly influencing results

For example, the mean CO concentration for the 20 meter road is approximately 22 % higher than the 100 meter upwind site for all wind directions. The mean CO concentration for the 20 meter road is approximately 55 % higher than the 100 meter upwind site for downwind conditions (winds from road).)

• Additional ongoing analyses investigate specific research questions, such as:

Evaluating the degree of other urban sources contributing to measurements under specific wind conditions [e g Henry et al (2011)]under specific wind conditions [e.g., Henry et al., (2011)]

Assessing how the highway and surrounding topography affect dispersion of near-road air pollutants (e.g., Baldauf et al., in preparation)

Understanding relationships between measured pollutants and influential factors (meteorology, traffic trends, etc.)

Evaluating data utilizing new real-time measurement approaches


g g pp

Overview map of Detroit


Detroit site: Eliza Howell Park


North View

Ground level views

East View West ViewEast View West View


Additional Analyses:Mobile monitoringg

• Real-time air pollution measurements on-board a mobile platform – allow greater spatial coverage of data representing 2-3 hour sampling periods.Vehicle as operated in Las Vegas and Detroit for 1 month mapping air• Vehicle was operated in Las Vegas and Detroit for ~1 month, mapping air pollution concentrations on-road and along side roads.

Real-time data:L ti (GPS)Location (GPS)Carbon monoxideBlack carbonParticle count in about 80 size binsParticle count in about 80 size bins (spans ~6 nanometers – 20 µm)Forward-facing video

Office of Research and Development

Mobile monitoring• Example black carbon map for Las Vegas (multiple laps over 3 hour sampling

periods averaged into 20 m spatial increments)Weekday, 8 11 AMb 8-11 AMbusy

arterials

highwayhighway


Ultrafine particles: measurementTwo UFP 3031s (TSI) and two EPC 3783s (TSI) tested in Las Vegas, Detroit, and at an ambient site in RTP.

3031 operation: particles charged, sized by electrical mobility, then counted via electrometer. -15 min data, six size bins (range 20 to >200 nm)

P f t bl t ti f- Performance: very stable autonomous operation for long periods of time. We had some data logging issues after a firmware upgrade that have been resolved.

3783 operation: particles grown through condensing water to their surface, counted by light scattering. -1 s (max rate) data, one size range (~ 7 nm – 1 µm).- Performance: initially problematic at near-road site and minimal data collection achieved. After system impro ements no ha e stable sampling at o r


improvements now have stable sampling at our ambient site. Requires monthly maintenance (wick change, water source).

Ultrafine particles: measurementBoth technologies demonstrated good precision at our ambient monitoring site in RTP

UFP3031#1 vs.

UFP3031#2

R = 0.994Mean(Y./X) = 1.06

R = 0.994Mean(Y./X) = 0.984

C3 83 #1EPC3783 #1 vs.

EPC3783 #2


Ultrafine particles: observations

Example comparison - March-April, LV (2010), Detroit (2011), RTP (2012)

600060006000

Las Vegas (20 m from road) RTP (ambient)Detroit (<10 m from road)

4000

5000

(cm

-3)

4000

5000

()

4000

5000

(cm

-3)

# cm

-3)

1000

2000

3000

PN

(

1000

2000

3000

1000

2000

3000

PN

(PN

(#

020-30 nm 30-50 nm 50-70 nm 70-100 nm 100-200 nm

020-30 nm 30-50 nm 50-70 nm 70-100 nm 100-200 nm

020-30 nm 30-50 nm 50-70 nm 70-100 nm 100-200 nm

Particle size (nm)20-30 30-50 50-70 70-100 100-200

Particle size (nm)20-30 30-50 50-70 70-100 100-200

Particle size (nm)20-30 30-50 50-70 70-100 100-200


~205,000 AADT ~180,000 AADTPN = particle number

Future plans…

• Raleigh NO2 Near Road Site In Collaboration with NCDENR

• Health Studies………..

Cardiovascular Study: Research Triangle Area Mobile Source E i i St d (RAMSES)Emissions Study (RAMSES)

Asthma Study: Near Roadways Exposure to Urban Air Pollutants Study (NEXUS)Pollutants Study (NEXUS)

• Roadway Design Studies………..

Sound walls

Vegetation


g

Who are the members of the EPA/FHWA Near Road team?Near Road team?

Project Team:• Strategic Project/Science Management

– Dan CostaCarlos Nunez– Carlos Nunez

– Doug Mckinney– Richard Baldauf– David Kryak– Prakash Bhave

• NRMRL – Project Management– Sue Kimbrough– Richard Shores

• EPA/FHWA Technical Working Group (including above)Vi t i M ti (FHWA) IAG P j t Offi– Victoria Martinez (FHWA) -- IAG Project Officer

– Dan Vallero (EPA IAG Project Officer)– Bill Mitchell– Donald Whitaker– Richard Baldauf– Gayle Hagler– James Hirtz– Jason Herrington– Carry Croghan

Paul Solomon


– Paul Solomon– Other EPA technical staff ……..

26

Appendixpp


Site selection criteria(many from Sierra Club/FHWA Settlement Agreement)

Selection Considerations Monitoring Protocol Criteria

Annual Average Daily Traffic (AADT) (> 150,000)

Only sites with more than 150,000 annual average daily traffic (AADT) are considered as candidates.

The geometric design of the facility, including the layout of ramps, interchanges and similar Geometric Design facilities, will be taken into account. Where geometric design impeded effective data

collection on MSATs and PM2.5, those sites were excluded from further consideration.

Topology (i.e., Sound Barriers, Road Elevation)

Sites located in terrain making measurement of Mobile Source Air Toxic (MSAT) concentrations difficult or that raise questions of interpretation of any results were not considered For example sharply sloping terrain away from a roadway could result in underElevation) considered. For example, sharply sloping terrain away from a roadway could result in under representation of pollutants.

Geographic Location Criteria applicable to representing geographic diversity within the U.S. as opposed to within any given city.

Availability of Data (Traffic Volume Data)Any location where data, including automated traffic monitoring data, meteorological or MSAT concentration data, was not readily available or instrumentation cannot be brought in y ( ) , y gto collect such data were not considered for inclusion in the study.

MeteorologySites will be selected based on their local meteorological conditions to assess the impact of climate on dispersion of emissions and atmospheric processes that affect chemical reactions and phase changes in the ambient air.

While not explicitly included in the Monitoring Protocol, the following selection criteria were deemed important to the selection process and were included

Downwind Sampling Any location where proper siting of downwind sampling sites was restricted due to topology, existing structures, meteorology, etc., excluded otherwise suitable sites for consideration.

Potentially confounding air pollutant sources The presence of confounding emission sources sometimes excluded otherwise suitable sites from consideration.

were included.


Site Access (Admin/Physical) Any location where site access, was restricted or prohibited either due to administrative or physical issues, was not considered for inclusion in the study.

Conceptual site design

Upwind Site (100 Meters)

Roadside Site (10 Meters)

100 Meter Downwind Site

300 Meter Downwind Site

(100 Meters)

Concentration Gradientce

ntra

tion

Concentration Gradientce

ntra

tion Hypothetical

Wind Flow

Distance

Con

c

Distance

Con

c


DistanceDistance

Overview map of Las Vegas

I-15 Site

S G


Source: Google Maps

Meteorology: McCarran Airport

Winds generally from the SSW, although diurnal variations exist


CO concentration box plots for full data set from December, 2008 through December, 2009: all sites, all wind directions (mean is the dotted line in each (box) (a) and histograms of the wind speed (b), wind direction (c), traffic volume (d)

Kimbrough, S., Baldauf, R., Hagler, G., Shores, R.C., Mitchell, W., Whitaker, D.A., Croghan, C.W., Vallero, D.A., 2012 Long-term continuous2012. Long-term continuous measurement of near-road air pollution in Las Vegas: Seasonal variability in traffic emissions impact on local air quality. Air Quality, Atmosphere & Health


Atmosphere & Health.

NO2 concentration box plots for full data set from December, 2008 through December, 2009: all sites, all wind directions (mean is the dotted line in each box) (a) and histograms of the wind speed (b), wind direction (c), traffic volume (d)


Seasonal NO2 trends (all wind directions)80

n (p

pb) 60

cent

ratio

n

40

Con

c

20

R d Li I id

nter

ring

mer Fall nter

ring

mer Fall nter

ring

mer Fall nter

ring

mer Fall

0-100 Meters 20 Meters 100 Meters 300 Meters

Red Line Inside Box = Mean

Black Line Inside Box = Median

Individual Points


Wint

Sprin

Summ Fa

Wint

Sprin

Summ Fa

Wint

Sprin

Summ Fa

Wint

Sprin

Summ FaIndividual Points

= Outliers

Hourly average NO2/NOX ratio box plots ( ) ll it ll i d diti (b) ll(a) all sites, all wind conditions; (b) all sites, downwind conditions (mean is the dotted line in each box))

1.2 1.2All wind conditions Winds from west

X R

atio

0.8

1.0

X R

atio

0.8

1.0

NO

2/N

OX

0.2

0.4

0.6

NO

2/N

OX

0.2

0.4

0.6

Distance (m)-100 20 100 300

0.0

Distance (m)-100 20 100 300

0.0


Black carbon (BC)

Black Carbon(all wind directions)

Black Carbon(winds from road)

m3 )

4000

5000

m3 )

4000

5000

ncen

tratio

n (n

g m

1000

2000

3000

ncen

tratio

n (n

g m

2000

3000

- 100 Meters 20 Meters 100 Meters 300 Meters

Con

0

1000

- 100 Meters 20 Meters 100 Meters 300 MetersC

on

0

1000

Red Line Inside Box = MeanBlack Line Inside Box = Median

All outliers not shown


Black Line Inside Box = MedianIndividual Points = Outliers

Hourly average PM2.5 box plots (a) all sites, all wind conditions; (b) all sites, downwind ; ( ) ,conditions (mean is the dotted line in each box)

50 50

All wind conditions Winds from west

Not all Not all

atio

n (µ

g/m

3 )

30

40

µg/m

3 30

40outliers shown

outliers shown

Con

cent

ra

0

10

20

0

10

20

Distance

-100 20 100 300

0

Distance

-100 20 100 300

0


Summary of continuous particulate (PM10, PM2 5 and PMC ) observations(PM10, PM2.5 and PMCoarse) observations with acceptable system status and volumetric flows

Location

Observations (Obs.) a System Status Volumetric Flows +/- 2 %Location y

Normal and Operating Mode Fully Functional

A (3 lpm)

B (1.67 lpm)

By Pass (12 lpm)

Station 1 108,714 95,601S i 2 112 464 8 40Station 2 112,464 85,405Station 3 106,245 48,769Station 4 103,868 14,088a TEOM data from Station 4 is from 12/11/2008 02/15/2010a TEOM data from Station 4 is from 12/11/2008-02/15/2010.


Detroit: Instrument Deployment - Overview

Core Instruments 10 Meters @ I-96 Roadside

100 Meter Downwind

300 Meter Downwind

100 Meter Upwind

EPA Method TO-11A Cartridge sampling X X X X

EPA Method TO-15 Canister sampling X X X Xp g

Continuous gas chromatograph X X X X

Continuous gas monitoring (CO, NOx ) X X X X

Continuous black carbon monitoring (Aethalometer) X X X X

Continuous fine particle (TEOM) X X X X

Integrated PM2.5 (FRM) X X X X

Wind speed/wind direction (sonic anemometer) X X X X

Meteorological monitoring (temp, RH, solar, etc.) X

Study Enhancements

Continuous Ultrafines (20 nm – 200+ nm) X X

Water-based CPC X X

Continuous CO2 monitoring X X X X

Michigan DOT -- Traffic data


Vehicle count, Vehicle speed, Vehicle class

Las Vegas Cut Section MeasurementsLong-Term MeasurementsFHWA/EPA Sites:Continuous and integrated samplingsampling4 sites (100 m upwind; 20, 100, 300 m downwind)Over one year of sampling ( )(Dec, 2008 – March, 2010)

Intensive MeasurementsSt ti hi l liStationary vehicle sampling:Continuous air quality measures~3 hrs per day (Oct-Nov, 2009)

Mobile Sampling:Electric car equipped with air quality analyzersDriving route 4-5x per day


Driving route 4 5x per day (~3 hrs, Oct-Nov, 2009)

Monitoring details

Mobile Electric Vehicle ~3 hrs per day (3-4 driving routes)Particulate MatterParticulate MatterUFP size distributions (EEPS)Coarse and fine size distributions (APS)Black carbon (Micro-aethalometer)

C t S ti M t

( )Gases

CO (Single Quantum Cascade Laser)

Cut Section MeasurementsCO and BC at bottom, middle and top

of cut section (Dec 2008-2009)Sonic anemometers at bottom and topSonic anemometers at bottom and top

of cut section (Nov 2009-March 2010)Bottom: 3m and 6m heightsTop: 6m and 10m heights


Top: 6m and 10m heights

Cut section effects

R lt i di t dResults indicated highest levels

occurred at-grade, during calm winds,during calm winds,

with this site impacted more by “fresh”

emissions


Wind Tunnel Simulation of Las Vegas Studyy


Wind Tunnel Simulation


Documents

EPA/Federal Highway Administration (FHWA) Near Road … · 2012. 8. 15. · EPA/Federal Highway Administration (FHWA) Near Road Collaboration Project: National Near: National Near-Road