appendix e-4: noise technical memorandum · the fta’s transit noise and vibration impact...

Appendix E-4: Noise Technical Memorandum

AshlandAvenueBusRapidTransitProject

EnvironmentalAssessment

Memorandum Date: August 8, 2013 Subject: Noise Prepared by: CDM Smith, Inc.

IntroductionTheChicagoTransitAuthority(CTA),incooperationwiththeChicagoDepartmentofTransportation(CDOT),DepartmentofHousingandEconomicDevelopment(DHED),andtheFederalTransitAuthority(FTA),isproposingtoimplementBusRapidTransit(BRT)featuresandservicealongAshlandAvenueinChicago,Illinois.ThelimitsfortheAshlandAvenueBusRapidTransit(BRT)Projectare:

IrvingParkRoadonthenorthto95thStreetonthesouth(approximately16.1miles)

CTAcurrentlyoperateslocalbusservicewithintheAshlandAvenueBRTProjectlimits.Theproposedimprovementsarelimitedinscopeandwouldbeimplementedwithinexistingroadwayrights‐of‐way:

Constructionof35medianBRTstationswithsheltersandpedestrianboardingareas

Upgradeoftrafficsignalsystemstoincludetransitsignalpriority

Implementationofqueuejumplanesandturnrestrictionsatintersections

Removaloftravellanestoaccommodateadesignatedbuslaneineachdirection

Pavementmillingandresurfacing

Streetscapeimprovementsincludingmedians,landscaping,andADA‐accessibilityupgrades

PurposeThismemorandumpresentsthenoiseanalysisconductedfortheproposedproject.Thesectionsthatfollowincludeadescriptionofnoisefundamentals,noiseimpactcriteria,andthenoiseanalysisresults.

AshlandAvenueBusRapidTransitProject:NoiseTechnicalMemorandumAugust8,2013Page2

NoiseMemo v2_BDSEDITS.docx

NoiseFundamentalsNoiseis“anysoundthatisundesiredorinterfereswithaperson’shearingofsomething”.1Noiseorsoundisapressureontheeardrumandthatismeasuredonascalefromonetoonebillion.Tosimplifythisscale,engineersandscientistshaveestablishedadecibelscale(dB)of1to180throughamathematicalprocesscalledalogarithm,whichiseasiertouse.Thehumanearcanonlyhearcertainfrequenciesofnoise,so,inordertoshowonlythelevelorfrequenciesthatcanbeheardbythehumanear,thescaleisgivenanA‐weighting,designatedbydBA.Thescaleof1to180dBAprovidesarangeforthesoundlevelsthatfallwithinahuman’snormalrangeofhearingforvarioustypesofnoises.Figure1providesanoverviewofseveraldifferenttypesofnoisesandwhatthesoundlevelisindBA.Thescaleprovidesabetterrepresentationoftheactualsoundlevelsandhowapersonwouldbeaffected.Trafficnoise,definedasunwantedsound,isassociatedwithhighway/transitprojectsandisusuallyinformofloudorpersistentnoisesfromcars,trucks,andbuses.Trafficnoisesaregeneratedfromengines,mufflers,andfromtirecontactwiththeroadway.

Noisesaffectpeopledifferentlyduetotheirenvironmentandothervariousfactors.Loudnoisessuchasacarhonkingitshornwouldbothermostpeoplewhiletheyweretryingtosleep,whileasofternoiseduringthedaymightbothercertainindividualsiftheyweretryingtostudyorconcentrateonadifficulttask.TheFTAhasdevelopedNoiseImpactCriteriafortransitprojectstodeterminewhenimpactsoccurasshowninFigure2.

Noiseimpactsarebasedoncomparingexistingoutdoornoiseslevelswithfuturenoiselevelsofproposedtransittypeprojects.Thisanalysisincludestheconsiderationofabsolutenoiselevelsandtheincreaseoverexistinglevelsinordertodeterminetheseverityoftheimpactcausedbytheproject.Anincreaseof3dB(A)isbarelyperceptible,anincreaseof5dBAisnoticeable,andthata

Figure 1: Typical Noise Levels

1 Webster’s New Collegiate Dictionary, 1975. G&C Merriam Company. Springfield, Massachusetts.



Figure 2: Noise Impact Criteria Thresholds

Source: Transit Noise and Vibration Impact Assessment, May 2006

10dB(A)increasewouldbeperceivedbysomeonetobeadoublingofthenoiselevel(loudness).Increasesof5‐10dB(A)wouldtendtobenoticeabletomostbutnotsubstantial.Anincreaseof10dB(A)ormorewouldbeperceivedbymostasasubstantialimpact.

Landusetypesarealsousedinthedeterminingthelevelandtypesofimpactsandaregroupedintothreecategories(1,2,and3),asshowninTable1.ThesecategoriesweredevelopedtohelpindeterminingwhatdBAlevelsofnoisewoulddisturbpeopleduringvariousactivitiesandatvariouslocations.WhendBAlevelsreachthepointthatitcreatesadisruptionforanactivity,itisconsideredanimpact.



Table 1: Land Use Categories and Metrics for Transit Noise Impact Criteria

Source: Transit Noise and Vibration Impact Assessment, May 2006

NoiseAssessmentTheFTA’sTransitNoiseandVibrationImpactAssessmentManual(FTA2006)hasthreelevelsofanalysisthatmaybeusedtoevaluatenoiseimpactsofatransitproject,dependingonthetypeandscaleoftheproject,thestageofprojectdevelopment,andtheenvironmentalsetting.Thethreelevelsofanalysisare:

Screeningprocedure

Generalassessment

Detailedanalysis

Anoisescreeningprocedurewasfirstperformedfortheprojectstudyarea.ThisanalysiswascompletedinaccordancewiththeFTAproceduresoutlinedintheTransitNoiseandVibrationImpactAssessmentManual.Thescreeningprocedureisusedtoidentifynoiseandvibration‐sensitivelandusesinthevicinityofaprojectandwhetherthereislikelytobeanimpact.Thescreeningproceduretakesintoaccountthenoiseimpactcriteria,thetypeofproject,andnoise‐sensitivelanduses.

Thescreeningprocedureforabuswaywasdeemedmostappropriateforthisnoiseanalysis.Thescreeningprocedureprovidesanimpactdistance,whichisthedistancefromthecenterlineoftheBRTprojectwherenoisesensitivereceptorswouldbeimpacted,whichisfarenoughouttoincludeallprobablenoiseimpactedlocations.Thisdistanceiscalculatedusingaworstcasescenarioforthe

Land Use Category

Noise Metric (dBA) Description of Land Use Category

1

Outdoor Leq(h)*

Tracts of land where quiet is an essential element in their intended purpose. This category includes lands set aside for serenity and quiet, and such land uses as outdoor amphitheaters and concert pavilions, as well as National Historic Landmarks with significant outdoor use. Also included are recording studios and concert halls.

2

Outdoor Ldn

Residences and buildings where people normally sleep. This category includes homes, hospitals and hotels where a nighttime sensitivity to noise is assumed to be of utmost importance.

3 Outdoor Leq(h)*

Institutional land uses with primarily daytime and evening use. This category includes schools, libraries, theaters, and churches where it is important to avoid interference with such activities as speech, meditation and concentration on reading material. Places for meditation or study associated with cemeteries, monuments, museums, campgrounds and recreational facilities can also be considered to be in this category. Certain historical sites and parks are also included.

* Leq for the noisiest hour of transit‐related activity during hours of noise sensitivity.



proposedbuswayprojectwithalowthresholdof50dBAastheimpactcriteria.BasedonFTA’sguidelines,thescreeningdistances,whichareprescribeddistancesforthenoiseanalysis,forabuswaysystemis500feet(unobstructed)and250feet(interveningbuildings).

LanduseswithinthescreeningdistanceswerereviewedtodeterminethecategorytypestobeanalyzedastheycorrespondwithTable1.LandusemapsofthecorridorareprovidedinAttachmentA.ThecategorytypesassociatedwiththisprojectareprimarilyLandUseCategory“2”.Industrialandcommerciallandusesarealsowithintheprojectarea;however,noiseimpactcriteriadonotapplytoindustrialorcommerciallandusesduetotheirhighernoiselevelactivities.

InordertoanalyzeandcomparespecificcategoriesofnoiseimpactsassociatedwiththeBuildAlternative,twonoiseassessmentbuffersat500feetand250feetfromthecenterlineofthebuswayfacility(centerofthenoise‐generatingactivity)weredeveloped.Theexistingnoiseenvironmentwasassumedtobe60dBAbasedontheFTATransitNoiseandVibrationImpactAssessmentManual(Figure2‐17).Basedonthescreeninganalysis,landusesincludedintheresidentiallandusecategorywerefoundtobelocatedwithinthenoisebuffers.Therefore,ageneralassessmentwasconductedtodeterminethenoiselevelsusingtheFTA’sNoiseImpactAssessmentSpreadsheet(seeAttachmentB).Theaveragenumberofbusesperhourwasassumedtobe12busesineachdirectionforthedaytimeaswellasnighttimehourstravelingat15.9milesperhour.

Theproposedprojectwouldbelocatedalonganexistingroadwaycorridor,inanurbansetting,andwouldnotbesubstantiallyincreasingthenumberoftransitvehiclesontheroadway.Table4showsthenoiselevelsat50,100,150,200feetfromtheproposedalignmentmeasuredfromcenterofnoisegeneratingactivity.

Table 4: Noise Level Impact Summary

Distance Project Ldn Existing Ldn Moderate Impact Criteria

Severe Impact Criteria

Impact

50 ft 59 dBA 56 dBA 58 dBA 63 dBA Moderate Impact

100 ft 55 dBA 52 dBA 58 dBA 63 dBA No



At50feetfromtheAshlandAvenuealignment,theincreaseinnoiselevelisexpectedtobe3dBAandthereceiverswouldmeettheModerateImpactCriteriaof58dB(A).Thecontourdistancetomoderateimpactis62feetandforsevereimpactis26feetfromthecenterofnoisegeneratingactivity.



EnvironmentalImpactsNo‐BuildAlternativeUnder theNo‐BuildAlternative, the projectwouldnot be constructed andno impacts to currentnoiselevelswouldoccur.

AshlandAvenueBRTProjectTheAshlandAvenueBRTProjectwouldhavenodirectimpactsonlandusesinthecorridorandisconsistent with existing land use, zoning and relevant community land use plans. The City ofChicago is committed to the proposed effort and additional land use studies are proposed toidentify further improvements to landusepolicies in thecorridor tosupportdevelopmentof theproposed project. In addition, the implementation of BRT would further support economicdevelopment plans by proving greater cohesion between land use and transportation. The BRTserviceandstreetenhancementscouldincentivizenewtransitorienteddevelopment(TOD)inthecorridor,whichwouldbeconsistentwithzoning.

BasedontheanticipatedfrequencyandspeedoftheproposedBRTservice,theproposedprojectisnotexpectedtoresultinanyseverenoiseimpactstotheprojectareawithintheexistingright‐of‐way.Receiverswithin62feetfromtheAshlandAvenuealignmentmeasuredfromcenterofnoisegeneratingactivitywouldexperienceamoderateimpact,ora3dBAincrease.Anincreaseof3dBAisbarelyperceptiblechangeandisnotexpectedtocreatedisruptionofnormalactivities.Also,noiselevelsareexpectedtobelowerwiththere‐designationofonetravellaneineachdirectionasacenterrunning,dedicatedbuslane.TheoveralltrafficvolumewithintheAshlandAvenuecorridorisexpectedtobereducedby35percentwithimplementationoftheproposedproject.RoadwaynoiseisthepredominantnoiseinfluenceintheareaandtheadditionalcontributionfromBRTtrafficwouldberelativelyminor.AsindicatedinChapter3oftheEnvironmentalAssessment,divertedtrafficwillbeabsorbedthroughouttherobust,Chicagoroadnetworkandnoothernotableincreasestonoiseareanticipatedonanyoneroadwaywithinthenetworkabsorbingthistrafficdiversion.

ConstructionNoise

No‐BuildAlternativeUnder theNo‐BuildAlternative, the projectwouldnot be constructed andno impacts to currentnoiselevelsduringconstructionwouldoccur.

AshlandAvenueBRTProjectThemajorconstructionactivitiesofthisprojectareexpectedtobeearthremoval,hauling,grading,andpaving.Generallyconstructionnoiseimpacts,suchastemporaryspeechinterferenceforpassersbyandindividualslivingorworkingneartheproject,canbeexpected.Insomeareas,constructionnoiseimpactscanbeexpectedtobegreaterduetothecloseproximityofexistinghousing.However,consideringtherelativelyshorttermnatureofconstructionnoise,theseimpacts



arenotexpectedtobesubstantial.Thecontractorcanlimittimesforwhichcertaintypesofconstructionoperationsmaybeundertaken.Thiswouldassistinminimizingimpactstosensitivereceptorsintheprojectvicinity.

ReferencesFederalTransitAdministration(FTA).2006.TransitNoiseandVibrationImpactAssessment,DepartmentofTransportation,FederalTransitAdministration,ReportNo.FTA‐VA‐90‐1003‐06,10 May2006.Availableat:http://www.fta.dot.gov/documents/FTA_Noise_and_Vibration_Manual.pdf.Accessed:May17,2013.

AttachmentALandUseMaps

UP

-NNorth

Legend

Inset

Scale

Proposed BRT Station

Proposed BRT Route

250 Ft Buffer

500 Ft Buffer

Residential

Retail/Service

Office/Professional

Urban Mix

Other Commercial

Institutional

Industrial, Warehousing, and Utilities; Open Space

Transportation, Communications, and Utilities

Open Space

Vacant or Under Construction

Water

Land Use

Data source:

Cook County Assessor

0 500250

Feet

Chicago

Figure 1Ashland BRT Project

Transit Noise AnalysisPage 1 of 17

MAZZAAM

Rectangle

MAZZAAM

Rectangle

UP

-N

North

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Scale


Proposed BRT Route

250 Ft Buffer

500 Ft Buffer

Residential

Retail/Service

Office/Professional

Urban Mix

Other Commercial

Institutional



Open Space


Water

Land Use

Data source:


0 500250

Feet

Chicago



MAZZAAM

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MAZZAAM

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North Branch Chicago River

UP

-N

UP

-NW

North

Legend

Inset

Scale


Proposed BRT Route

250 Ft Buffer

500 Ft Buffer

Residential

Retail/Service

Office/Professional

Urban Mix

Other Commercial

Institutional



Open Space


Water

Land Use

Data source:


0 500250

Feet

Chicago



MAZZAAM

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UP

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UP

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North

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250 Ft Buffer

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Urban Mix

Other Commercial

Institutional



Open Space


Water

Land Use

Data source:


0 500250

Feet

Chicago



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NCS MD-NUP-W MD-W

North

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Scale


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250 Ft Buffer

500 Ft Buffer

Residential

Retail/Service

Office/Professional

Urban Mix

Other Commercial

Institutional



Open Space


Water

Land Use

Data source:


0 500250

Feet

Chicago



MAZZAAM

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Legend

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Institutional



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Water

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Data source:


0 500250

Feet

Chicago



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Institutional



Open Space


Water

Land Use

Data source:


0 500250

Feet

Chicago



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South Branch Chicago River

Chicago Sanitary and Ship Canal

North

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250 Ft Buffer

500 Ft Buffer

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Urban Mix

Other Commercial

Institutional



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Water

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Data source:


0 500250

Feet

Chicago



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iver

HC

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Institutional



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Data source:


0 500250

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Chicago



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Institutional



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Data source:


0 500250

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Proposed BRT Route

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Institutional



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Data source:


0 500250

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Chicago



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Data source:


0 500250

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NoiseMemo

AttachmentBFTANoiseImpactAssessmentSpreadsheets

Federal Transit AdministrationFederal Transit Administration

Noise Impact Assessment SpreadsheetNoise Impact Assessment Spreadsheet

C i ht 2007 HMMH ICopyright 2007 HMMH Inc.

Noise Impact Criteriaversion: 7/3/2007 Noise Impact CriteriaNoise Impact Criteria(FTA Manual Fig 3-1)

Project: Asland BRT Corridor

Noise Impact Criteria(FTA Manual, Fig 3-1)


85


Project Results Summary 85

(FTA Manual, Fig 3-1)

Project Results Summary

Existing Ldn: 60 dBA

85


Existing Ldn: 60 dBAT l P j d 59 dBA 80

85

Total Project Ldn: 59 dBA

75

80

A)Receiver Parameters Total Noise Exposure: 63 dBA

75

80


Receiver: Receiver at 50' from BRT Centerline Increase: 3 dB75

80

dB

A)

Receiver: Receiver at 50' from BRT Centerline Increase: 3 dBL d U C t 2 R id ti l I t? M d t

70

75

dn

(d

BA

)

Land Use Category: 2. Residential Impact?: Moderate70

75

e/L

dn

(d

BA

Existing Noise (Measured or Generic Value): 60 dBA70

e/L

dn

(d

Existing Noise (Measured or Generic Value): 60 dBA

Distance to Impact Contours 65

70

sure

/Ld

n (

d

Distance to Impact Contours

Di t t M d I t C t

59 dBA60

65

70

Exp

osu

re/L

d

Moderate ImpactDist to Mod. Impact Contour (S 1 2) 62 ft

59 dBA60

65

Exp

osu

re

Moderate Impact

(Sources 1+2): 62 ft59 dBA

55

60

65

No

ise

Exp

osu

re

Moderate Impact

Severe ImpactDist to Sev. Impact Contour 59 dBA

55

60

No

ise

Exp

os

Moderate Impact

Severe Impactp(Sources 1+2): 26 ft

59 dBA

55

60

No

ise

Exp

os

Moderate Impact

Severe Impact

( ) 26 ft

Noise Source Parameters

59 dBA

55

60

ect

No

ise

Exp

os

Moderate Impact

Severe Impact

Receiver at 50' from BRT CenterlineNoise Source Parameters

N b f N i S 2

59 dBA

50

55

60

Pro

ject

No

ise Severe Impact

Receiver at 50' from BRT Centerline

Number of Noise Sources: 2 50

55

Pro

ject

N Receiver at 50' from BRT Centerline

50

Pro

je BRT Centerline

Noise Source Parameters Source 1 45

50

Pro

je BRT Centerline

Noise Source Parameters Source 1

S T Hi h /T it

45

P

Source Type: Highway/Transit40

45

40 45 50 55 60 65 70 75 80Specific Source: Buses (diesel-powered) Source 1 Results 40

40 45 50 55 60 65 70 75 80p ( p )

Daytime hrs 1 Leq(day): 49 7 dBA

4040 45 50 55 60 65 70 75 80

Daytime hrs 1 Leq(day): 49.7 dBASpeed (mph) 15 9 Leq(night): 49 7 dBA

4040 45 50 55 60 65 70 75 80

Existing Noise Exposure (dBA)Speed (mph) 15.9 Leq(night): 49.7 dBAf / 56 1 dBA

40 45 50 55 60 65 70 75 80

Existing Noise Exposure (dBA)

Avg. Number of Events/hr 12 Ldn: 56.1 dBA


Nighttime hrs 1Nighttime hrs 1

Speed (mph) 15.9p ( p )

Avg. Number of Events/hr 12 Increase in Cumulative Noise Levels AllowedAvg. Number of Events/hr 12 Increase in Cumulative Noise Levels Allowed(FTA Manual Fig 3-2)

Di t Di t f S t R i (ft) 50 20

Increase in Cumulative Noise Levels Allowed(FTA Manual, Fig 3-2)

Distance Distance from Source to Receiver (ft) 50 20


Number of Intervening Rows of Buildings 020

B)


g g

Adjustments Noise Barrier? No

20

B)Adjustments Noise Barrier? No

No 15

20

e (d

B)

No

No

15

ease

(d

B)

No

10

15

ncr

ease

(d

B

No10

re I

ncr

ease

10

re I

ncr

ea


10

sure

In

crea


5

10

xpo

sure

In

Source Type: Highway/Transit

3 dB

5

e E

xpo

sure

Specific Source: Buses (diesel-powered) Source 2 Results3 dB

5

e E

xpo

s

Specific Source: Buses (diesel powered) Source 2 Results

Daytime hrs 3 Leq(day): 49 7 dBA3 dB

5

ois

e E

xpo

s

Daytime hrs 3 Leq(day): 49.7 dBAS d ( h) 15 9 L ( i ht) 49 7 dBA

3 dB

0

5

No

ise

Ex

Speed (mph) 15.9 Leq(night): 49.7 dBA

3 dB

040 45 50 55 60 65 70 75 80

No

ise


040 45 50 55 60 65 70 75 80

No


g

Incremental Ldn (Src 1-2): 59.2 dBA

40 45 50 55 60 65 70 75 80

Existing Noise Exposure (dBA)Incremental Ldn (Src 1 2): 59.2 dBA

Nighttime hrs 3

40 45 50 55 60 65 70 75 80


Moderate Impact Severe Impact Receiver at 50' from BRT CenterlineNighttime hrs 3

S d ( h) 1 9


Moderate Impact Severe Impact Receiver at 50' from BRT CenterlineSpeed (mph) 15.9

g ( )

Moderate Impact Severe Impact Receiver at 50' from BRT Centerline

Avg. Number of Events/hr 12Avg. Number of Events/hr 12

Distance Distance from Source to Receiver (ft) 50Distance Distance from Source to Receiver (ft) 50

N b f I t i R f B ildiNumber of Intervening Rows of Buildings

Adjustments Noise Barrier? Noj

NoNo

NoNo

NNo








85






85



85


75

80


75

80



80

dB

A)

Receiver: Receiver at 100' from BRT Centerline Increase: 1 dBL d U C t 2 R id ti l I t? N

70

75

dn

(d

BA

)

Land Use Category: 2. Residential Impact?: None70

75

e/L

dn

(d

BA


e/L

dn

(d



70

sure

/Ld

n (

d


Di t t M d I t C t

60

65

70

Exp

osu

re/L

d

Moderate ImpactDist to Mod. Impact Contour (S 1 2) 62 ft 60

65

Exp

osu

re

Moderate Impact

(Sources 1+2): 62 ft

55 dBA55

60

65

No

ise

Exp

osu

re

Moderate Impact

Severe ImpactDist to Sev. Impact Contour

55 dBA55

60

No

ise

Exp

os

Moderate Impact

Severe Impactp(Sources 1+2): 26 ft

55 dBA55

60

No

ise

Exp

os

Moderate Impact

Severe Impact

( ) 26 ft

Noise Source Parameters55 dBA55

60

ect

No

ise

Exp

os

Moderate Impact

Severe Impact


N b f N i S 2

55 dBA

50

55

60

Pro

ject

No

ise Severe Impact


Number of Noise Sources: 2

55 dBA

50

55

Pro

ject


50

Pro

je BRT Centerline

Noise Source Parameters Source 1 45

50

Pro

je BRT Centerline


S T Hi h /T it

45

P


45


40 45 50 55 60 65 70 75 80p ( p )


4040 45 50 55 60 65 70 75 80


4040 45 50 55 60 65 70 75 80


40 45 50 55 60 65 70 75 80












B)


g g


20


No 15

20

e (d

B)

No

No

15

ease

(d

B)

No

10

15

ncr

ease

(d

B

No10

re I

ncr

ease

10

re I

ncr

ea


10

sure

In

crea


5

10

xpo

sure

In

Source Type: Highway/Transit 5

e E

xpo

sure

Specific Source: Buses (diesel-powered) Source 2 Results5

e E

xpo

s


Daytime hrs 3 Leq(day): 45 2 dBA 1 dB

5

ois

e E

xpo

s


1 dB0

5

No

ise

Ex

Speed (mph) 15.9 Leq(night): 45.2 dBA1 dB

040 45 50 55 60 65 70 75 80

No

ise


1 dB0

40 45 50 55 60 65 70 75 80

No


g


40 45 50 55 60 65 70 75 80


Nighttime hrs 3

40 45 50 55 60 65 70 75 80



S d ( h) 1 9



g ( )






NoNo

NoNo

NNo








85






85



85


75

80


75

80



80

dB

A)


70

75

dn

(d

BA

)


75

e/L

dn

(d

BA


e/L

dn

(d



70

sure

/Ld

n (

d


Di t t M d I t C t

60

65

70

Exp

osu

re/L

d


65

Exp

osu

re

Moderate Impact


55

60

65

No

ise

Exp

osu

re

Moderate Impact


55

60

No

ise

Exp

os

Moderate Impact

Severe Impactp(Sources 1+2): 26 ft 55

60

No

ise

Exp

os

Moderate Impact

Severe Impact

( ) 26 ft

Noise Source Parameters 52 dBA

55

60

ect

No

ise

Exp

os

Moderate Impact

Severe Impact


N b f N i S 252 dBA

50

55

60

Pro

ject

No

ise Severe Impact


Number of Noise Sources: 252 dBA

50

55

Pro

ject

N Receiver at 150' from BRT Centerline52 dBA

50

Pro

je BRT Centerline


52 dBA

45

50

Pro

je BRT Centerline


S T Hi h /T it

45

P


45


40 45 50 55 60 65 70 75 80p ( p )


4040 45 50 55 60 65 70 75 80


4040 45 50 55 60 65 70 75 80


40 45 50 55 60 65 70 75 80












B)


g g


20


No 15

20

e (d

B)

No

No

15

ease

(d

B)

No

10

15

ncr

ease

(d

B

No10

re I

ncr

ease

10

re I

ncr

ea


10

sure

In

crea


5

10

xpo

sure

In


e E

xpo

sure


e E

xpo

s



5

ois

e E

xpo

s


1 dB0

5

No

ise

Ex

Speed (mph) 15.9 Leq(night): 42.6 dBA1 dB0

40 45 50 55 60 65 70 75 80

No

ise


1 dB040 45 50 55 60 65 70 75 80

No


g


40 45 50 55 60 65 70 75 80


Nighttime hrs 3

40 45 50 55 60 65 70 75 80



S d ( h) 1 9



g ( )






NoNo

NoNo

NNo








85






85



85


75

80


75

80



80

dB

A)


70

75

dn

(d

BA

)


75

e/L

dn

(d

BA


e/L

dn

(d



70

sure

/Ld

n (

d


Di t t M d I t C t

60

65

70

Exp

osu

re/L

d


65

Exp

osu

re

Moderate Impact


55

60

65

No

ise

Exp

osu

re

Moderate Impact


55

60

No

ise

Exp

os

Moderate Impact

Severe Impactp(Sources 1+2): 26 ft 55

60

No

ise

Exp

os

Moderate Impact

Severe Impact

( ) 26 ft

Noise Source Parameters55

60

ect

No

ise

Exp

os

Moderate Impact

Severe Impact


N b f N i S 2 50 dBA50

55

60

Pro

ject

No

ise Severe Impact


Number of Noise Sources: 2 50 dBA50

55

Pro

ject


50 dBA50

Pro

je BRT Centerline


50 dBA

45

50

Pro

je BRT Centerline


S T Hi h /T it

45

P


45


40 45 50 55 60 65 70 75 80p ( p )


4040 45 50 55 60 65 70 75 80


4040 45 50 55 60 65 70 75 80


40 45 50 55 60 65 70 75 80












B)


g g


20


No 15

20

e (d

B)

No

No

15

ease

(d

B)

No

10

15

ncr

ease

(d

B

No10

re I

ncr

ease

10

re I

ncr

ea


10

sure

In

crea


5

10

xpo

sure

In


e E

xpo

sure


e E

xpo

s



5

ois

e E

xpo

s

Daytime hrs 3 Leq(day): 40.7 dBAS d ( h) 15 9 L ( i ht) 40 7 dBA 0 dB0

5

No

ise

Ex

Speed (mph) 15.9 Leq(night): 40.7 dBA 0 dB040 45 50 55 60 65 70 75 80

No

ise


0 dB040 45 50 55 60 65 70 75 80

No


g


40 45 50 55 60 65 70 75 80


Nighttime hrs 3

40 45 50 55 60 65 70 75 80



S d ( h) 1 9



g ( )






NoNo

NoNo

NNo

appendix e-4: noise technical memorandum · the fta’s transit noise and vibration impact...

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