HomeMy WebLinkAboutAGENDA REPORT 2008 0521 CC REG ITEM 09C ITEM q-G -
CITE'OF MOORPARK,CALIFORNIA
City Council('Meeting
of ,(008"
ACTION:
MOORPARK CITY COUNCI o
AGENDA REPORT ter: -
1kf ,�3 -�,---
TO: Honorable City Council /?
FROM: David A. Bobardt, Planning Director
Prepared By: Joseph Fiss, Principal (Manner
DATE: May 2, 2008 (CC Meeting of 5/21/2008)
SUBJECT: Consider Noise Study for State Route 23 Freeway Soundwalls
Adjacent to Tract 4975 (Toscana Neighborhood)
BACKGROUND
On October 19, 2006, staff reported to the City Council on freeway noise in the
residential areas of the Carlsberg Specific Plan (Serenata), and why soundwalls were
not required to be constructed as part of the Carlsberg Specific Plan project or the SR-
23 freeway widening project currently under construction. On February 7, 2007, the
City Council authorized preparation of a noise study to identify the feasibility of the
construction of freeway soundwalls adjacent to the homes on Crabapple Court at the
eastern boundary of Tract 4975 (Toscana at Serenata neighborhood) within the
Carlsberg Specific Plan Area, bordering the SR-23 freeway. The City contracted with
Wieland Associates, Inc., a firm specializing in noise studies, to determine the potential
effectiveness of a soundwall in this area.
DISCUSSION
Wieland recently completed their study regarding the effectiveness of a soundwall at the
western edge of the freeway, within the Caltrans right-of-way. The purpose of the study
was to evaluate the traffic noise levels at existing homes on Crabapple Court, in the City
of Moorpark, for a retrofit sound wall on the west side of State Route 23. The noise-
sensitive areas of concern at the residences are the exterior living spaces.
Wieland conducted noise measurements in this area, and with their computer noise
model, assessed the need for a 14-foot high soundwall on the western edge of the
freeway, within the Caltrans right-of-way as shown in Attachment 1. The top-of-slope
adjacent to the freeway shoulder was determined to be the most efficient location for
reducing freeway noise based on the surrounding topography. The edge of the right-of-
way is not considered a good location for a soundwall because it is lower in elevation
than both the freeway and the homes, and a soundwall works by interrupting the "line of
190041
Honorable City Council
May 21, 2008
Page 2
sight" between the noise source and the receptor. A full analysis of a soundwall in this
location is included in Attachment 2.
Although the City has no adopted standards for determining if a soundwall would be
effectively reduce noise at a reasonable cost, Caltrans has standards for feasibility and
reasonableness, used when State funding is considered for a soundwall project. The
noise study evaluated the potential soundwall under the Caltrans criteria and
determined that a soundwall as shown in Attachment 1 would effectively reduce freeway
noise at a reasonable cost. It would reduce future peak hour noise by 5 to 8 dB at the
impacted residences at a cost of about $299,000, according to Wieland's estimate. This
estimate was confirmed by the Public Works Department to be close to actual bid prices
for the soundwalls recently constructed on the SR-23. Although not determined
necessary to meet City outdoor noise criteria, staff recommends that the soundwall be
extended south of the Tierra Rejada off-ramp to provide additional noise buffering that
would benefit all 18 homes on Crabapple Court in anticipation of future traffic increases
on the SR-23 freeway, particularly by heavy trucks.
ENVIRONMENTAL DOCUMENTATION
Environmental documentation will be prepared once a soundwall is designed.
FISCAL IMPACT
Design, permitting, and construction costs are not known at this time. It is anticipated
that these costs could be covered by existing money in the Carlsberg Mitigation Fund.
Allocation of money to the soundwall project would return to the City Council for further
consideration.
STAFF RECOMMENDATION
Direct staff to proceed with soundwall design and permitting.
Attachments:
1. Location of Potential Soundwall
2. Traffic Noise Impact Technical Report
\\mor_pri_sery\City Share\Community Development\DEV PMTS\R P D\LENNAR GENERAL\Sound Wall\Sound Wall Agenda Report
080521.doc
o.
SR-23
CRABAPPLE COURT
r �
Soundwall \
Location in
Noise Study ° �
Staff
Recommended
Extension �
Potential Soundwall Location "SW-1"
and
Staff-Recommended Extension
CC ATTACHMENT 1
f 00 043
STATE ROUTE 23 SOUTHBOUND,
NORTH OF TIERRA REJADA ROAD, MOORPARK
Caltrans Reference: N/A
Approximate Postmile Limits: 7-Ven-23 PM 10.0110.4
TRAFFIC NOISE IMPACT TECHNICAL REPORT
Project File 07.030.00
March 26, 2008
Prepared for:
City of Moorpark
799 Moorpark Avenue
Moorpark, CA 93021
Submitted to:
California Department of Transportation
District 7
Prepared by:
Wieland Acoustics, Inc.
2691 Richter Avenue, Suite 114
Irvine, CA 92606
Tel: 9491474-1222 Fax: 9491474-9122
www.wielandacoustics.com
CC ATTACHMENT 2 VJ0044
Table of Contents
I. EXECUTIVE SUMMARY...............................................................................................................................1
II. NOISE IMPACT TECHNICAL REPORT.......................................................................................................5
A. INTRODUCTION............................................................................................................................................5
B. PROJECT DESCRIPTION ................................................................................................................................5
C. FUNDAMENTALS OF TRAFFIC NOISE...............................................................................................................5
SoundCharacteristics................................................................................................................................5
Decibels.......................................................................................................................................................7
A-Weighting................................................................................................................................................7
SoundPropagation.....................................................................................................................................9
Effectsof Noise........................................................................................................................................10
NoiseDescriptors.....................................................................................................................................10
D. FEDERAL Et STATE POLICIES AND PROCEDURES............................................................................................11
FHWA Noise Abatement Criteria...........................................................................................................11
Caltrans Noise Barrier Guidelines.........................................................................................................I1
E. STUDY METHODS AND PROCEDURES............................................................................................................12
F. EXISTING NOISE ENVIRONMENT...................................................................................................................14
G. FUTURE NOISE ENVIRONMENT, IMPACTS,AND CONSIDERED MITIGATION........................................................16
H. IMPACTS AND CONSIDERED ABATEMENT.......................................................................................................18
Assessmentof Impact..............................................................................................................................18
AbatementMeasures...............................................................................................................................18
I. CONSTRUCTION NOISE...............................................................................................................................21
J. REFERENCES.............................................................................................................................................22
LIST OF FIGURES
FIGURE II-1. LOCATION OF THE STUDY AREA...................................................................................6
FIGURE II-2. COMMON NOISE SOURCES AND A-WEIGHTED NOISE LEVELS......................................8
FIGURE II-3. NOISE MEASUREMENT&MODELING LOCATIONS,EXISTING WALLS&PROPOSED SOUND
WALL.........................................................................................................................13
LIST OF TABLES
TABLE I-1. ESTIMATED FUTURE PEAK HOUR TRAFFIC NOISE LEVELS&IMPACTS........................2
TABLE I-2. PREDICTED NOISE LEVELS,LEQ(H)AND INSERTION LOSS(I.L.,NOISE REDUCTION),
DBAFOR SOUND WALL...............................................................................................3
TABLE I-3. CALCULATION OF REASONABLE ALLOWANCE PER RECEPTOR.....................................4
TABLE II-1. EXISTING PEAK HOUR TRAFFIC NOISE LEVELS&IMPACTS.......................................15
TABLE II-2. FUTURE TRAFFIC PARAMETERS FOR TNM MODEL....................................................16
TABLE II-3. ESTIMATED FUTURE PEAK HOUR TRAFFIC NOISE LEVELS&IMPACTS......................17
TABLE II-4. PREDICTED NOISE LEVELS,LEQ(H)AND INSERTION LOSS(I.L.,NOISE REDUCTION),
DBAFOR SOUND WALL.............................................................................................19
TABLE II-5. DATA FOR REASONABLENESS DETERMINATION,SW-1..............................................19
TABLE II-6. CALCULATION OF REASONABLE ALLOWANCE PER RECEPTOR...................................20
TABLE 11-7. DETERMINATION OF REASONABLENESS OF RECOMMENDED SOUND WALL...............20
TABLE II-8. TYPICAL CONSTRUCTION EQUIPMENT NOISE WITH AND WITHOUT MITIGATION........22
1
LIST OF APPENDICES
APPENDIX A. NOISE MEASUREMENTS
APPENDIX B. TRAFFIC DATA
APPENDIX C. CALIBRATION OF TNM TO EXISTING CONDITIONS&CALCULATION OF PEAK NOISE
HOUR LEVELS
APPENDIX D. CALCULATION OF FUTURE PEAK NOISE HOUR LEVELS
APPENDIX E. SOUND WALL ANALYSIS
APPENDIX F. GEOMETRIC DATA FOR SOUND WALL SW-1
11
I. EXECUTIVE SUMMARY
The purpose of this study is to evaluate the traffic noise levels at existing residences(single family
homes)on Crabapple Court,in the City of Moorpark, for a retrofit sound wall on the southbound side
of State Route 23.It is noted that this study does not involve a Caltrans or Ventura County
Transportation Commission(VCTC)project;rather the study was conducted for the City of Moorpark
in response to residents' concerns about freeway traffic noise.The noise-sensitive areas of concern at
the residences are the exterior living spaces.No sound walls currently exist at the site. However,the
residences are buffered from the traffic noise by existing property line walls.
Two initial noise measurements were obtained within the study area in order to identify the peak
noise hour. Subsequent noise measurements were obtained at four locations throughout the study area
in order to document the existing noise environment;traffic data(traffic volumes,vehicle mix, and
speeds)was gathered simultaneously with these measurements.Measured noise and traffic data was
then used to calibrate a computer noise model of the study area. Eleven additional sites were selected
for noise modeling.The results, summarized in Table 1-1 on page 2,indicate that the peak noise hour
level currently ranges from 57 to 66 dBA at the considered receivers.
Future traffic noise levels in the study area were predicted using the FHWA TNM model(version
2.5).Table I-1 on page 2 provides the results of our analysis at the fifteen receiver locations used in
this study(four measured receivers plus eleven modeled receivers).Referring to the table,it is
estimated that future peak noise hour levels in the study area will range from 59 to 68 dBA.
Based on the analysis,it is concluded that the FHWA and Caltrans noise abatement criteria will be
approached or exceeded at six of the receivers considered in this study.Therefore,noise abatement
has been considered at these locations.
An analysis was conducted to identify the necessary heights and locations of sound walls needed to
comply with the FHWA criterion and the Caltrans noise barrier design guidelines.The results are
summarized in Table 1-2 on page 3.One sound wall,SW-1,was considered in the analysis.The
calculations indicate that SW-1 is feasible.Table 1-3 (page 4)identifies the height and length,the
estimated cost,and the reasonable allowance for SW-1.Referring to the table,it is noted that SW-1 is
considered both feasible and reasonable.
1
J:90047
Table 1-1. Estimated Future Peak Hour Traffic Noise Levels It Impacts
Noise
Abatement
Existing Future Noise Increase Category
Location or Worst Hour Worst-Case (+)or Decrease and Impact
Receiver Address Noise Level Noise Level ( ) Criterion Type'
1 4348 Crabapple 65 67 +2 B (67) A/E
Court
3' House from
2 North End of 65 67 +2 B (67) A/E
Crabapple
Court
5 House from
3 North End of 66 68 +2 B (67) A/E
Crabapple
Court
7w--House from
4 North End of 65 67 +2 B (67) A/E
Crabapple
Court
5 4272 Crabapple 66 67 +1 B (67) A/E
Court
11 House from
6 North End of 64 66 +2 B (67) A/E
Crabapple
Court
12 House from
7 North End of 62 63 +1 B (67) None
Crabapple
Court
6 House from
8 South End of 63 65 +2 B (67) None
Crabapple
Court
5,n House from
9 South End of 63 65 +2 B (67) None
Crabapple
Court
4 House from
10 South End of 62 64 +2 B (67) None
Crabapple
Court
3'House from
11 South End of 62 64 +2 B (67) None
Crabapple
Court
12 4142 Crabapple 62 64 +2 B (67) None
Court
House at South
13 End of 61 63 +2 B (67) None
Crabapple
Court
14 4285 Crabapple Court (2nd Row) 57 59 +2 B (67) None
15 4143 Crabapple Court (2 nd Row) 60 62 +2 B (67) None
Notes:
1. A/E=Approaches or Exceeds Noise Abatement Criteria
2
:_990048
Table 1-2. Predicted Noise Levels, Leq(h)and Insertion Loss (I.L., Noise Reduction), d8A for Sound Wall
With Wall With Wall With Wall With Wall With Wall
H = 1.8 m H =2.4 m H = 3.0 m H =3.7 m H =4.3 m
Without (6') (81) (10') (12') (14')
Receiver Wall Leq(h) I.L. Leq(h) I.L. Leq(h) I.L. Leq(h) I.L. Leq(h) I.L.
1 67 63 4 63 4 62 5 62" 5 61 6
2 67 64 3 63 4 63 4 62" 5 62 5
3 68 63 5 62 6 61 7 60' 8 59 9
4 67 64 3 63 4 62 5 61` 6 61 6
5 67 64 3 63 4 62 5 61` 6 61 6
6 66 63 3 62 4 61" 5 61 5 60 6
7 63 62 1 61 2 61" 2 60 3 60 3
8 65 64 1 64 1 64 1 64" 1 64 1
9 65 64 1 64 1 64 1 63" 2 63 2
10 64 63 1 63 1 63 1 63" 1 63 1
ill 64 63 1 63 1 63 1 63 1 63 1
12'---
2 64 63 1 63 1 63 1 63 1 63 1
137---
3 63 63 0 63 0 63 0 63 0 63 0
14 59 57 2 57 2 56 3 56" 3 56 3
15 62 60 2 60 2 59 3 59 3 59 3
Notes:
Breaks line of sight between 3.5 m (11.5')-high exhaust stack and 1.5 m (5')-high receiver at
impacted locations.
1. Receivers are further than 500 feet from the wall and are therefore not subject to the line of
sight requirement.
3
CD
Table 1-3. Determination of Reasonableness of Recommended Sound Wall
Approximate Approximate Cost of Approximate Recommended
Noise Linear Length of Masonry Sound Wall Cost of Reasonable Sound Wall is
Barrier Recommended Recommended at Recommended Recommended Allowance Per Reasonable(Yes
ID Location Wall Height Sound Wall Height Sound Wall Noise Barrier or No)
SW-1 See Figure II-3 4.3m(14') 259m (850') $268.30 per sq. m. $299,000 $418,000 YES
(page 13) ($24.93 per sq. ft.)
Notes:
1. Per Caltrans Traffic Noise Analysis Protocol [Reference 1] and the most recently published base allowance(2006)at:
http://www.dot.ca.gov/hq/env/noise/index.htm
L.•
C" 4
d
II. NOISE IMPACT TECHNICAL REPORT
The following sections will provide a description of the project, a brief description of traffic noise and
its characteristics,a description of the applicable policies regarding traffic noise abatement,the
methods and procedures used in this study,a description of the existing and future noise environment,
impacts,and recommended abatement measures.
A. Introduction
The purpose of this study is to evaluate the traffic noise levels at existing residences(single family
homes)on Crabapple Court,in the City of Moorpark,for a retrofit sound wall on the southbound side
of State Route 23.Crabapple Court is located north of Tierra Rejada Road and to the west of the SR-
23 freeway. (Refer to Figure II-1 on page 6 for the location of the study area.)It is noted that this
study does not involve a Caltrans or Ventura County Transportation Commission(VCTC)project;
rather the study was conducted for the City of Moorpark in response to residents' concerns about
freeway traffic noise.
B. Project Description
The noise-sensitive areas of concern at the residences are the exterior living spaces.No sound walls
currently exist at the site.However,the residences are buffered from the traffic noise by existing
property line walls that range in height from approximately 5.5' to 9'.The study area includes 18 first
row residences on the east side of Crabapple Court and 10 second row residences on the west side of
Crabapple Court.
C. Fundamentals of Traffic Noise
The following sections briefly describe the fundamentals needed to understand traffic noise,its
measurement, and the way it is perceived by the human ear.
Sound Characteristics
Sound may be thought of as mechanical energy of a vibrating object transmitted by pressure waves
through a medium to the human ear.The medium of main concern is air.Noise,on the other hand,is
defined as sound that is loud,unpleasant,unexpected or undesired.
In its most basic form,a continuous sound can be described by its frequency(pitch)and its amplitude
(loudness).For a given single pitch of sound,the sound pressure waves are characterized by a
sinusoidal periodic (recurring with regular intervals)wave.The number of times per second that the
wave passes from a period of compression through a period of rarefaction and starts another period of
compression is referred to as the frequency of the wave.Frequency is expressed in cycles per second,
or Hertz(Hz). One Hertz equals one cycle per second.High frequencies are sometimes more
conveniently expressed in units of kilohertz(kHz)or thousands of Hertz.The extreme range of
5
: '. G 051
t.
Eq 014 t � W
gE a.�"
to r
•
GA T
S,4 � 4#°
DEL
G 7
3
O -
0,2005 Thomas Bros.Maps p ■ ■
Figure 11-1. Location of the Study Area
6
N
frequencies that can be heard by the healthiest human ear spans from 16 to 20 Hz on the low end to
about 20,000 Hz on the high end.Frequencies are heard as the pitch or tone of sound.High
frequencies produce high-pitched sounds;low frequencies produce low-pitched sounds.Very-low-
frequency airborne sound of sufficient amplitude may be felt before it can be heard, and is often
confused with earthborne vibrations.
The pressures of sound waves continuously change with time or distance,and within certain ranges.
The ranges of these pressure fluctuations are called the amplitude of the pressure waves.Whereas the
frequency of the sound waves is responsible for the pitch or tone of a sound,the amplitude determines
the loudness of the sound.Loudness of sound increases and decreases with the amplitude.
Decibels
Sound pressures can be measured in units called microPascals(µPa). However,expressing sound
levels in terms ofµPa would be very cumbersome since it would require a wide range of very large
numbers.For this reason, sound pressure levels are described in logarithmic units of ratios of actual
sound pressures to a reference pressure squared.These units are called bels.In order to provide a finer
resolution,a bel is subdivided into 10 decibels,abbreviated dB.
Since decibels are logarithmic units, sound pressure levels cannot be added or subtracted by ordinary
arithmetic means.For example,if one automobile produces a sound pressure level of 70 dB when it
passes an observer,two cars passing simultaneously would not produce 140 dB.In fact,they would
combine to produce 73 dB.This same principle can be applied to other traffic quantities as well.In
other words,doubling the traffic volume on a street or the speed of the traffic will increase the traffic
noise level by 3 dB. Conversely,halving the traffic volume or speed will reduce the traffic noise level
by 3 dB.
A-Weighting
Sound pressure level alone is not a reliable indicator of loudness.The frequency or pitch of a sound
also has a substantial effect on how humans will respond.While the intensity of the sound is a purely
physical quantity,the loudness or human response depends on the characteristics of the human ear.
Human hearing is limited not only to the range of audible frequencies,but also in the way it perceives
the sound pressure level in that range. In general,the healthy human ear is most sensitive to sounds
between 1,000 Hz and 5,000 Hz,and perceives both higher and lower frequency sounds of the same
magnitude with less intensity. In order to approximate the frequency response of the human ear,a
series of sound pressure level adjustments is usually applied to the sound measured by a sound level
meter.The adjustments, or weighting network, are frequency dependent.
The A-scale approximates the frequency response of the average young ear when listening to most
ordinary everyday sounds.When people make relative judgments of the loudness or annoyance of a
sound,their judgments correlate well with the A-scale sound levels of those sounds.A-weighted
7
IJ O 053
sound levels are abbreviated as dBA.A range of noise levels associated with common in-and outdoor
activities are shown in Figure H-2.
Threshold of pain 120 dB(A)
Disco 110 dB(A)
Textile mill
Printing plant 100 dB(A)
Jackhammer at 50'
Power lawn mower at 5' 90 dB(A)
Heavy truck at 50'
Concrete mixer at 50 80 dB(A) ........................•
Inside car at 40 mph 10 dB change generally
:perceived as twice or halt as loud
Vacuum cleaner at 10' 70 dB(A) .......................
Car,60 mph at 100'
Conversational speech 60 dB(A) .........................
5 dB change generally
Large transformer at 50' .......................;Perceived as quite noticeable
Urban residence 50 dB(A) """""""""""
:3 dB change is generally barely
""""""""""""perceptible
Small town residence
40 dB(A) I dB change is generally not
........................noticeable
Soft whisper at 6'
30 dB(A)
North rim of Grand Canyon t
20 dB(A)
10 dB(A)
Threshold of hearing t 0 dB(A)
Figure 11-2. Common Noise Sources and A-Weighted Noise Levels
8
Sound Propagation
From the source to the receiver,noise changes both in level and frequency spectrum.The most
obvious is the decrease in noise as the distance from the source increases.The manner in which noise
reduces with distance depends on the following important factors:
• Geometric spreading from point and line sources
• Ground absorption
• Atmospheric effects and refraction
• Shielding by natural and manmade features,noise barriers,diffraction, and reflection
Geometric Spreading. Sound from a small localized source(approximating a"point" source)radiates
uniformly outward as it travels away from the source in a spherical pattern.The sound level
attenuates or drops-off at a rate of 6 dBA for each doubling of the distance.This decrease is referred
to as the inverse square law.However,highway traffic noise is not a single, stationary point source of
sound.The movement of the vehicle makes the source of the sound appear to emanate from a line
(line source)rather than a point when viewed over some time interval.This results in cylindrical
spreading rather than the spherical spreading of a point source, and a drop-off rate of 3 dBA for each
doubling of distance.
Ground Absorption.Most often,the noise path between the highway and the observer is very close to
the ground.Noise attenuation from ground absorption and reflective wave canceling adds to the
attenuation due to geometric spreading.Traditionally,the excess attenuation has also been expressed
in terms of attenuation per doubling of distance.TNM allows for the input of various different ground
types including pavement,water,hard soil,loose soil,lawn,field grass,granular snow and powder
snow.
Atmospheric Effects.Research has shown that atmospheric conditions can have a profound effect on
noise levels within 60m(200')from a highway.Wind has been shown to be the single most important
meteorological factor within approximately 150m(500'),while vertical air temperature gradients are
more important over longer distances.Other factors such as air temperature and humidity,and
turbulence,also have significant effects.As discussed in Section E,below,the effect of atmospheric
conditions on the modeling/analysis process is minimized by taking noise measurements during
appropriate atmospheric conditions.
Shielding.A large object in the path between a noise source and a receiver can significantly attenuate
noise levels at that receiver.The amount of attenuation provided by this"shielding"depends on the
size of the object,and frequencies of the noise levels.Natural terrain features, such as hills and dense
woods, as well as manmade features, such as buildings and walls can significantly alter noise levels.
Walls are often specifically used to reduce noise.
9
t�ju055
Effects of Noise
People react to sound in a variety of ways.Human tolerance to noise depends on a variety of
acoustical characteristics of the source,as well as environmental characteristics.These factors are
briefly discussed below:
1. The level,variability in level(dynamic range),frequency spectrums and time patterns of noise.
Exposures to very high noise levels can damage hearing.A high level is more objectionable than
a low-level noise,and intermittent truck peak noise levels are more objectionable than the
continuous level of fan noise. Humans have better hearing sensitivities in the high frequency
region than in the low.This is reflected in the A-scale,which de-emphasizes the low frequency
sounds. Studies indicate that the annoyance or disturbance correlates with the A-scale.
2. The amount of background noise present before the intruding noise.People tend to compare an
intruding noise with the existing background noise. If the new noise is readily identifiable or
considerably louder than the background or ambient,it usually becomes objectionable.
3. The nature of the work or living activity that is exposed to the noise source.Highway traffic noise
might not be disturbing to workers in a factory or office,but the same noise might be annoying or
objectionable to people sleeping at home or studying in a library.An automobile horn at 2:00
a.m. is more disturbing than the same noise in traffic at 5:00 p.m.
Under controlled conditions in an acoustics laboratory,the trained healthy human ear is able to
discern changes in sound levels of 1 dBA when exposed to steady, single frequency("pure tone")
signals in the mid-frequency range. Outside of such controlled conditions,the trained ear can detect
changes of 2 dBA in normal environmental noise. It is widely accepted that the average healthy ear,
however,can barely perceive noise level changes of 3 dBA.A change of 5 dBA is readily perceptible.
As discussed earlier with regard to A-weighting,the human response curve of frequencies in the
audible range is not linear,i.e.,humans do not hear all frequencies equally well.The human
perception of loudness is also not linear.Two noise sources do not sound twice as loud as one noise
source. However,based on numerous studies,it is generally accepted that a change of 10 dBA in
noise level is perceived as being twice or half as loud.
Noise Descriptors
Traffic noise can vary significantly over time.To describe the fluctuating noise both Caltrans and
FHWA use the energy equivalent sound level,abbreviated Leq.This is a single number
representation of the fluctuating sound level in dBA over a specified time period.For Caltrans noise
studies,this time period is the single noisiest hour of the day.
10
�` i�05G
D. Federal Ft State Policies and Procedures
FHWA Noise Abatement Criteria
The Federal-Aid Highway Program Manual,Volume 7,Chapter 7,Section 3 (FHPM 7.7.3)
establishes the following noise abatement criteria(NAC)for different activity categories:
Activity NAC,
Category 1-Hour Leq Description of Activities
A 57 dBA Exterior of lands on which serenity and quiet are of extraordinary
significance and serve an important public need.
Exterior of picnic areas, recreation areas, playgrounds, active
B 67 dBA sports areas, parks, residences, motels, hotels, schools, churches,
libraries and hospitals.
C 72 dBA Exterior of developed lands, properties, or activities not included in
Categories A or B above.
D N/A Undeveloped lands.
E 52 dBA Interior of residences, motels, hotels, public meeting rooms,
schools, churches, libraries, hospitals and auditoriums
Leq is the equivalent,or average,sound level during the noisiest 1-hour period of the day.
A significant traffic noise impact is assessed when the predicted noise levels approach or exceed the
NAC identified in the above table.As defined in Caltrans' Traffic Noise Analysis Protocol[Reference
11, a noise level approaches the NAC if it is within 1 dBA of the NAC.The interior NAC of Category
E applies where no exterior activity area is identified;or where the interior,but not the exterior,
activities would be affected by the traffic noise.
Caltrans Noise Barrier Guidelines
Caltrans' noise barrier design policy includes the following guidelines:
• Noise barriers should provide at least 5 dB of noise reduction at an impacted receiver.
• Noise barriers may not exceed 4.9m(14')in height when located 15' or less from the edge of the
traveled way, and should not exceed 16' in height when located more than 15' from the traveled
way.
• Noise barriers should block the line-of-sight from a 1.5m(5')-high receiver to a 3.5m(111/x')-
high truck exhaust stack in the nearest travel lane.
• Mitigation must be considered when traffic noise impacts for the design year approach or exceed
the noise abatement criteria for the existing land use("approach"is defined as within 1 dBA of
the noise abatement criteria).
• Mitigation must be considered when the traffic noise impacts for the design year represent a
substantial increase over the existing noise levels.A"substantial increase"is defined as 12 dBA
or more.
11
E. Study Methods and Procedures
In order to determine the existing peak noise hour and to document the existing noise environment,
measurements were obtained in August 2007 and February 2008 at a total of six locations throughout
the study area.Refer to Figure II-3 on page 13 for these locations.The noise measurements were also
used to calibrate a 3-dimensional computer noise model for the SR-23 freeway utilizing the FHWA
TNM(Version 2.5) software.
The ambient noise level measurements were obtained by positioning the sound level meter on the
property at a height of 5' above the ground.The instrument was calibrated prior to obtaining the
measurement.Noise measurements were not taken when:
• The pavement in the area was not generally dry;
• Winds were greater than 12 miles per hour;
• Non-typical noise such as from aircraft flyovers,construction,sirens,unusual pedestrian activity,
and parked idling vehicles occurred; and
• Relative humidity exceeded 90 percent.
The instrumentation used to obtain the noise measurements consisted of integrating sound level
meters(Models 712, 820,824 and 870),and acoustic calibrators(Models CAL200 and CAL250)
manufactured by Larson Davis Laboratories.The sound level meters were calibrated before each
measurement.The accuracy of the calibrators is maintained through a program established by the
manufacturer,and is traceable to the National Bureau of Standards.All instrumentation meets the
requirements of the American National Standards Institute(ANSI)S 1.4-1971.
The highway traffic noise prediction model used to model noise levels was FHWA TNM(Version
2.5).TNM predicts noise levels based on traffic volumes, speeds,traffic mix, site conditions,and
distance from the roadway to the receiver.TNM relies on 3-dimensional input data to model the study
area.The northing,easting, and elevation of the data points used to describe the layout and profile of
the freeway,ramps,existing barriers,topography and the noise-sensitive receivers in the traffic noise
model were obtained from the referenced freeway CAD(.dxf)files,provided by Caltrans, and
residential site and grading plans provided by the City of Moorpark.Additional wall and building
height data was obtained with field measurements.
Two long-term ambient noise measurements were initially obtained at locations LT1 and LT2 in
August 2007 for a continuous 24-hour period to determine the peak noise hour.The peak noise hour
was determined to occur between 6 a.m. and 7 a.m. In February 2008,two noise measurements were
obtained during the entire 7 a.m.to 8 a.m. hour at Receivers 1 and 5,and two were obtained for
twenty minutes within that hour at Receivers 14 and 15.Traffic counts and speed measurements were
conducted simultaneously with the noise measurements. (The measurements and traffic data were not
obtained during the peak hour since sunrise was after 6 a.m. on the day of the measurements.The 7
a.m.to 8 a.m.hour was the closest hour to the peak noise hour during which light conditions were
favorable.)The traffic counts were obtained by videotaping traffic on the freeway and southbound
12
F'�0('S8
I 4348 Crabapple Court Proposed Sound Wall SW 1
Y
2
LT1 -4300 Crabapple Court
3
4
14-4285 Crabapple Court
4272 Crabapple Court
8
10
g
15-4143 Crabapple Court 11
12
LTZ 4142 Crabapple Court
a`
Long-term noise measurement location O Short-term noise measurement location Location of existing walls
Noise modeling location " Location of Proposed Sound Wall SW-1
a Figure 11-3. Noise Measurement&Modeling Locations, Existing Walls &Proposed Sound Wall
C` 13
off-ramp at Tierra Rejada Road,and then reviewing the tape to identify the number and type of
vehicles in each lane.Vehicles were classified as autos,medium trucks and heavy trucks.Traffic
speed data was gathered by measuring the time taken for vehicles to pass between two points a known
distance apart.The noise measurements were then used,along with the traffic data,to calibrate the
TNM model.Refer to Appendix A for a complete listing of the measurement data and the equipment
used in the study.The traffic count and speed data is provided in Appendix B.The results of the
calibration analysis are provided in Appendix C.
Eleven additional locations were selected for modeling in order to adequately cover the study area.
F. Existing Noise Environment
The primary noise source affecting the homes within the study area is traffic on SR-23 and the
southbound off-ramp at Tierra Rejada Road.Existing block walls at the rear of the properties on the
east side of Crabapple Court,which range in height from approximately 5.5' to 9',provide some
noise reduction at the homes under consideration in this study.
The homes in the study area are located below the freeway elevation.The ground slopes down from
the west edge of the freeway before rising again to the elevation of the property-line walls at the
homes such that a slight gully is formed between the homes and the freeway. It is noted that the right-
of-way line is generally located within this gully and,therefore,is generally lower than both the
freeway and the homes on Crabapple Court.
As indicated in the previous section,calibration measurements were obtained between 7 a.m. and 8
a.m.,while the peak noise hour occurred between 6 a.m. and 7 a.m. Using long-term noise
measurements obtained during the study,it was possible to determine the difference in average noise
levels between the peak noise hour and the 7 a.m.to 8 a.m.hour.The peak noise hour levels were
estimated by applying this difference to the measured and modeled receivers in the calibration
analysis.Refer to Appendix C for the estimated peak noise hour calculations.The measurement and
modeling positions are presented graphically in Figure H-3 (page 13), and are described in further
detail in Table 11-1 (page 15).The table also identifies the estimated existing peak noise hour Leq at
each location.
14
Table 11-1. Existing Peak Hour Traffic Noise Levels It Impacts
Noise Existing Noise
Abatement Peak Level
Number of Category Noise Measured
Location or Type of Units and Hour or Impact
Receiver Address Development Represented Criterion Level Modeled? Type
4348 Crabapple Single Family
1 Court Home 1 B (67) 65 Measured None
3ra House from Single Family
2 North End of Home 2 B (67) 65 Modeled None
Crabapple Court
5 House from Single Family
3 North End of Home 2 B (67) 66 Modeled A/E
Crabapple Court
7 House from Single Family
4 North End of Home 2 B (67) 65 Modeled None
Crabapple Court
4272 Crabapple Single Family
5 Court Home 2 B(67) 66 Measured A/E
11 House from Single Family
6 North End of Home 2 B (67) 64 Modeled None
Crabapple Court
12 House from Single Family
7 North End of Home 1 B (67) 62 Modeled None
Crabapple Court
6 House from Single Family
8 South End of Home 1 B(67) 63 Modeled None
Crabapple Court
5 House from Single Family
9 South End of Home 1 B (67) 63 Modeled None
Crabapple Court
4w--House from Single Family
10 South End of Home 1 B (67) 62 Modeled None
Crabapple Court
THouse from Single Family
11 South End of Home 1 B(67) 62 Modeled None
Crabapple Court
4142 Crabapple Single Family
12 Court Home 1 B (67) 62 Modeled None
House at South Single Family
13 End of Crabapple Home 1 B (67) 61 Modeled None
Court
14 4285 Crabapple Single Family 7 B (67) 57 Measured None
Court (2 nd Row) Home
4143 Crabapple Single Family
15 Court(2nd Row) Home 3 B (67) 60 Measured None
Notes:
1. A/E=Approaches or Exceeds Noise Abatement Criteria
15
G. Future Noise Environment, Impacts, and Considered Mitigation
The calibrated TNM model was used, along with the future traffic parameters identified in Table H-2,
to identify the future worst-case noise levels in the study area.Table H-3 (page 17)provides the
future traffic noise levels at each of the receiver locations. (Refer to Appendix D for the calculations.)
Table 11-2. Future Traffic Parameters for TNM Model
SR-23
Parameter Travel Lanes Off-Ramp
Vehicles per hour per lane 1,950 "1,200
(vphpl)'
Truck mix
North of Tierra Rejada Rd. 94.75%, 3.90%, 1.35% 94.75%, 3.90%, 1.35%
South of Tierra Rejada Rd. 94.34%, 4.55%, 1.11%
Traffic Speed' 65 mph Varies- 35 mph to 65 mph
Notes:
1. Provided by staff at Caltrans District 7.
2. Based on most recent published truck mix(2006)obtained from Caltrans'website
at: http://www.dot.ca.gov/hq/traffops/saferesr/trafdata/
As indicated in Table II-3 (page 17),it is estimated that the future noise level will be 59 to 68 dBA at
the noise-sensitive locations within the study area.At six receiver positions,(1 through 6),the worst
case noise level approaches or exceeds the FHWA criterion of 67 dBA for Category B land uses.At
the remaining receiver positions the noise levels are below the FHWA criterion.
16
Table 11-3. Estimated Future Peak Hour Traffic Noise Levels & Impacts
Noise
Abatement
Existing Future Noise Increase Category
Location or Worst Hour Worst-Case (+)or Decrease and Impact
Receiver Address Noise Level Noise Level (-) Criterion Type'
1 4348 Crabapple 65 67 +2 B (67) A/E
Court
3' House from
2 North End of 65 67 +2 B (67) A/E
Crabapple
Court
S House from
3 North End of 66 68 +2 B (67) A/E
Crabapple
Court
7 House from
4 North End of 65 67 +2 B (67) A/E
Crabapple
Court
5 4272 Crabapple 66 67 +1 B (67) A/E
Court
11 House from
6 North End of 64 66 +2 B (67) A/E
Crabapple
Court
12 1h House from
7 North End of 62 63 +1 B (67) None
Crabapple
Court
6 House from
8 South End of 63 65 +2 B (67) None
Crabapple
Court
5 House from
9 South End of 63 65 +2 B (67) None
Crabapple
Court
4 House from
10 South End of 62 64 +2 B (67) None
Crabapple
Court
3' House from
11 South End of 62 64 +2 B (67) None
Crabapple
Court
12 4142 Crabapple 62 64 +2 B (67) None
Court
House at South
13 End of 61 63 +2 B (67) None
Crabapple
Court
14 4285 Crabapple 57 59 +2 B 67 None
Court (2nd Row) ( )
15 4143 Crabapple Court (2nd Row) 60 62 +2 B (67) None
Notes:
1. A/E=Approaches or Exceeds Noise Abatement Criteria
17
H. Impacts and Considered Abatement
Assessment of Impact
Referring to Table H-3 on page 17,it may be concluded that the future noise levels in the study area
approach or exceed the FHWA noise abatement criterion of 67 dBA for Category B land uses at
Receivers 1 through 6.
Abatement Measures
As discussed in Section F,the impacted receivers are below the elevation of the freeway.Therefore,
the most acoustically efficient location for a sound wall is at the top-of-slope adjacent to the freeway
shoulder.The right-of-way line is not considered a good location for a sound wall because,as
mentioned in Section F,this line is typically below the elevations of both the freeway and the homes.
For these reasons only the edge-of-shoulder location has been considered for a possible sound wall.
Proposed sound wall heights,locations and anticipated noise reduction at each receiver location are
shown in Table H-4(page 19),and in Figure H-3 (page 13).Refer to Appendix E for the sound wall
analysis.The proposed barrier represents the height required to provide: a) a minimum attenuation of
5 dBA at the impacted receivers; and,b)the maximum noise reduction achievable(within the
reasonableness guidelines,see below).
All sound walls recommended in this study must be feasible and reasonable.Feasibility is an
engineering consideration,which states that the recommended sound walls must achieve a minimum
noise reduction of 5 dBA at the impacted receivers.Reasonableness, on the other hand,is a more
subjective consideration.Using procedures developed by Caltrans [Reference 1],a sound wall will be
considered reasonable in this study if it costs less than the reasonable allowance per benefited
residence identified in Table H-5 (page 19). (A benefited residence is defined as a dwelling unit that
is expected to receive a noise reduction of at least 5 dBA from the sound wall.)
One new sound wall, SW-1,has been considered in this study.This sound wall is located close to the
top of the slope at the edge of shoulder of the southbound lanes and runs from adjacent to the
northernmost house on Crabapple Court to the twelfth house from the north end.If constructed at the
maximum permitted height of 4.3m(14') at the edge of shoulder,the sound wall will reduce the
future peak noise hour level by 5 to 8 dB at impacted Receivers 1 through 6.Therefore,the wall is
considered to be a feasible abatement measure at these locations.Referring to Table H-5 on page 19,
and Tables II-6 and H-7 on page 20,this wall will benefit 11 homes at a cost of about$299,000. Since
this is less than the reasonable allowance of$418,000,the sound wall is also considered reasonable.
18
Table 11-4. Predicted Noise Levels, Leq(h) and Insertion Loss (I.L., Noise Reduction), d8A for
Sound Wall
With Wall With Wall With Wall With Wall With Wall
H = 1.8 m H = 2.4 m H =3.0 m H = 3.7 m H =4.3 m
Without (6') (81) (10') (12') (14')
Receiver Wall Leq(h) I.L. Leq(h) I.L. Leq(h) I.L. Leq(h) I.L. Leq(h) I.L.
1 67 63 4 63 4 62 5 62* 5 61 6
2 67 64 3 63 4 63 4 62* 5 62 5
3 68 63 5 62 6 61 7 60* 8 59 9
4 1 67 64 3 63 4 62 5 61* 6 61 6
5 67 64 3 63 4 62 5 61* 6 61 6
6 66 63 3 62 4 61* 5 61 5 60 6
7 63 62 1 61 2 61* 2 60 3 60 3
8 65 64 1 64 1 64 1 64* 1 64 1
9 65 64 1 64 1 64 1 63* 2 63 2
10 64 63 1 63 1 63 1 63* 1 63 1
11 64 63 1 63 1 1 63 1 63 1 63 1
12 64 63 1 63 1 63 1 63 1 63 1
13 63 63 0 63 0 63 0 63 0 63 0
14 59 57 2 57 2 56 3 56* 3 56 3
15 62 60 2 60 2 59 3 59 3 59 3
Notes:
* Breaks line of sight between 3.5 m (11.5')-high exhaust stack and 1.5 m (5')-high receiver at
impacted locations.
1. Receivers are further than 500 feet from the wall and are therefore not subject to the line-of-
sight requirement.
Table 11-5. Data for Reasonableness Determination, SW-1
SOUND WALL ID: SW-1
PREDICTED,W/O SOUND WALL
Predicted Noise Level, Leq(h), dBAl 68
Change re. No-build, dBA1 0
PREDICTED, WITH SOUND WALL H=1.8 H=2.4 H=3.0 H=3.7 H=4.3m
m (6') m(8') m (10') m(12') (14')
Insertion Loss(Noise Reduction), dBA1 5 6 7 8 9
Benefited Receptors 2 2 9 11 11
New Highway, or More Than 50%of Receptors NO NO NO NO NO
Predate 1978?(Yes or No)
Reasonable Allowance Per Benefited Receptor2 $34,000 $36,000 1 $36,000 $36,000 $38,000
Notes:
1. At critical receiver(0).
2. Reasonable allowance obtained from Caltrans Traffic Noise Analysis Protocol [Reference 1].
19
�rl065
Table 11-6. Calculation of Reasonable Allowance Per Receptor
Reduction of Modified
Reasonable Reduction of Reasonable Reasonable
Allowance Reasonable Fraction of Reasonable Allowance Allowance
Per No. of Allowance Total Allowance Per Per
Noise Benefited Benefited Per Noise Reasonable Per Noise Benefited Benefited
Barrier ID Receptor Receptors Barrier Allowance Barrier Receptor Receptor
SW-1 $38,000 11 $418,000 N/A N/A N/A N/A
Total Reasonable Allowance for Abatement $418,000
Estimated Project Cost x 0.5 N/A
Result N/A
Table 11-7. Determination of Reasonableness of Recommended Sound Wall
Approximate Approximate Cost of Approximate Recommended
Noise Linear Length of Masonry Sound Wall Cost of Reasonable Sound Wall is
Barrier Recommended Recommended at Recommended Recommended Allowance Per Reasonable(Yes
ID Location Wall Height Sound Wall Height Sound Wall Noise Barrier or No)
SW-1 See Figure II-3 4.3m (14') 259m (850') $268.30 per sq. M. $299,000 $418,000 YES
(page 13) ($24.93 per sq. ft.)
Notes:
1. Per Caltrans Traffic Noise Analysis Protocol [Reference 1] and the most recently published base allowance (2006) at:
http://www.dot.ca.gov/hq/env/noise/index.htm
20
0�
1. Construction Noise
Construction noise represents a short-term impact to ambient noise levels.Receivers that would be
affected by traffic noise would be adversely affected by construction noise as well.Typical
construction equipment and the related noise levels are shown in Table II-8 (page 22).It is noted that
construction activities would be limited to the construction of the recommended sound wall.
The following mitigation measure should be used to minimize adverse construction noise:
The control of noise from construction activities shall conform to Section 5-1,"Sound Control
Requirements",in the Standard Special Provisions. Sound control shall conform to the provisions in
Section 7-1.011,"Sound Control Requirement",of the Standard Specifications and these special
provisions:
"The noise level from the Contractor's operations, between the hours of 9:00 pm and 6:00 am shall
not exceed 86 dBA at a distance of 15 meters(50 feet). This requirement in no way relieves the
Contractor from responsibility for complying with local ordinances regulating noise level.
"Said noise level requirement shall apply to all equipment on the job or related to the job, including
but not limited to trucks, transit mixers or transient equipment that may or may not be owned by the
Contractor. The use of loud sound signals shall be avoided in favor of light warnings except those
required by safety laws for the protection of personnel.
Full compensation for conforming to the requirements of this Section shall be considered as included
in the prices paid for the various contract items of work involved and no additional compensation will
be allowed therefor."
21
Table 11-8. Typical Construction Equipment Noise With and Without Mitigation
Mitigated
Unmitigated Noise
Noise Level, Level, Distance
Equipment Mitigation dBA dBA (ft.)
Pile Driver Sound barrier and muffler on exhaust 103 95 25
Pavement Breaker Muffler 105 100 1 3
Diesel Driven
Electric Welder Mufflers and enclosure 93 76 23
Diesel Driven Air
Compressor Muffler 105 85 3
Air Tracked Drill Acoustical enclosure 104 83 23
Chain Saw
Gasoline None 113 113 3
Electric None 86 86 3
Sinker Drill Acoustical enclosure 95 78 3
Earth Movers
Front Loader Muffler 79 75 50
Backhoe Muffler 85 57 50
Dozer Muffler 80 57 50
Grader Muffler 91 57 50
Truck Muffler 91 57 50
Paver Muffler 89 80 50
Material Handlers
Concrete Mixer Muffler 85 75 50
Crane Muffler 83 75 50
Jack Hammer Muffler or acoustical enclosure 88 75 50
Source: Urban Mass Transportation Administration, 1974; U.S. EPA, 1971.
J. References
1. Traffic Noise Analysis Protocol for New Highway Construction, Reconstruction, and Retrofit
Barrier Projects. California Department of Transportation(Caltrans),Division of Environmental
Analysis.August 14,2006.
2. Technical Noise Supplement. Caltrans.October 1998.
3. Highway Design Manual—Chapter 1100 Highway Traffic Noise Abatement.Caltrans. September
1, 2006.
4. Grading and Site Plans for Crabapple Court. Drawing No. 00-ML-10616.Ramseyer and
Associates.July 1998. Supplied by the City of Moorpark.
5. Grading and Site Plans for Crabapple Court. Drawing No. 02-ML-10684. VTN West,Inc.July
2002. Supplied by the City of Moorpark.
6. Grading and Site Plans for Crabapple Court. Drawing No. 02-ML-10665. VTN West, Inc.April
2002. Supplied by the City of Moorpark.
22
1i"L➢t;68
7. "711545ea031.dxf',"711545ea032.dxf', "711545ea033.dxf', "711545ea034.dxf',
"711545ea035.dxf', "711545ea036.dxf', "711545ea037.dxf'. 3-D CAD files of existing freeway
layout and topography.Provided by Caltrans.July 5 and July 10,2007.
23
r 1 001 i9
APPENDIX A
Noise Measurements
Notes:
The data provided in this Appendix was used in the calibration/existing peak noise hour analysis of
Appendix C.
�0 0W 0
Instrumentation
The following instrumentation was used to obtain the noise measurements:
• Larson Davis Model 820 Sound Level Meter,S/N 1632
• Larson Davis Model 870 Sound Level Meter, S/N 0157
• Larson Davis Model 712 Sound Level Meter, S/N 0555
• Larson Davis Model 712 Sound Level Meter, S/N 0556
• Larson Davis Model 824 Sound Level Meter, S/N 3536
• Larson Davis Model CAL200 Acoustical Calibrator,S/N 2916
• Larson Davis Model CAL250 Acoustical Calibrator,S/N 2966
• Sony CCD-TRV58 Hi8 camcorder
i�)0 07f I
APPENDIX 8
Traffic Data
Note:
The data provided in this Appendix was used in the calibration/existing peak noise hour analysis of
Appendix C.
:BOO "r'2
Table 8-1. Traffic Counts for Receivers 1, 5, and 12.
Date: 7 February 2008
Time: 7:00 a.m. - 8:00 a.m.
Duration: 1 Hour
Number of Vehicles
Lane(s) Vehicle Type Counted During 1 Hour Estimated in 1 Hour
Northbound Outside Lane Auto 543 543
Medium Truck 32 32
Heavy Truck 57 57
Northbound Middle Lane Auto 1005 1005
Medium Truck 20 20
Heavy Truck 6 6
Northbound Inside Lane Auto 1014 1014
Medium Truck 0 0
Heavy Truck 0 0
Southbound Inside Lane Auto 1480 1480
Medium Truck 14 14
Heavy Truck 2 2
Southbound Middle Lane Auto 599 599
Medium Truck 34 34
Heavy Truck 65 65
Southbound Outside Lane Auto 701 701
/ Southbound Off-Ramp Medium Truck 17 17
Heavy Truck 8 8
Table B-2. Traffic Counts for Receiver 14
Date: 7 February 2008
Time: 7:30 a.m. - 7:55 a.m.
Duration: 25 Minutes
Number of Vehicles
Counted During 25
Lane(s) Vehicle Type Minutes Estimated in 1 Hour
Northbound Outside Lane Auto 231 554
Medium Truck 13 31
Heavy Truck 35 84
Northbound Middle Lane Auto 424 1016
Medium Truck 9 22
Heavy Truck 3 7
Northbound Inside Lane Auto 434 1040
Medium Truck 0 0
Heavy Truck 0 0
Southbound Inside Lane Auto 529 1268
Medium Truck 5 12
Heavy Truck 1 2
Southbound Middle Lane Auto 246 590
Medium Truck 16 38
Heavy Truck 22 53
Southbound Outside Lane Auto 284 681
/ Southbound Off-Ramp Medium Truck 8 19
Heavy Truck 4 10
Table B-3. Traffic Counts for Receiver 15
Date: 7 February 2008
Time: 7:01 a.m. - 7:22 a.m.
Duration: 21 Minutes
Number of Vehicles
Counted During 21
Lane(s) Vehicle Type Minutes Estimated in 1 Hour
Northbound Outside Lane Auto 209 603
Medium Truck 9 26
Heavy Truck 10 239
Northbound Middle Lane Auto 370 1067
Medium Truck 3 9
Heavy Truck 2 6
Northbound Inside Lane Auto 345 995
Medium Truck 0 0
Heavy Truck 0 0
Southbound Inside Lane Auto 625 1803
Medium Truck 5 14
Heavy Truck 1 3
Southbound Middle Lane Auto 230 663
Medium Truck 8 23
Heavy Truck 31 89
Southbound Outside Lane Auto 268 773
/ Southbound Off-Ramp Medium Truck 6 17
Heavy Truck 2 6
Table B-4. Traffic Speeds for Calibration of TNM Model
Date: 7 February 2008
Time: 7:00 a.m. - 8:00 a.m.
Lane(from Southbound Northbound
W to E) 1 (Off- 1 (Before
Ramp) Off-Ramp) 2 3 4 5 6
42.6 61.8 72.8 67.4 81.2 69.1 68.4
66.1 58.5 61.8 73.6 71.1 66.6 57.0
60.7 62.2 74.0 57.5 73.2 62.9 63.9
56.1 67.5 59.3 60.2 69.8 73.7 67.1
64.6 73.8 60.4 57.0 74.2 67.0 68.9
55.7 66.7 66.7 55.6 74.6 71.3 61.3
Speed (mph) 57.3 57.9 56.6 71.5 75.6 65.5 58.2
61.6 67.5 65.8 62.5 75.1 63.9 67.6
53.5 70.7 57.1 70.6 51.0 52.2
62.5 52.9 45.7 72.4 67.0 62.7
62.1 61.9 67.9 76.5 71.8 51.4
46.2 1 1 57.8 71.1 70.9 66.7
62.5
Average
-Speed (mph) 57.8 64.5 63.9 61.2 73.8 66.7 62.1
= )00 S
APPENDIX C
Calibration of TNM to Existing Conditions
Et
Calculation of Existing Peak Noise Hour Levels
Notes:
The calibration results and K-factors for all measurement locations are summarized as follows:
Measured Noise Predicted Noise Level from Delta Between
Receiver Level, dBA Uncalibrated TNM, dBA Values, dBA K-Factors
1 63.2 63.9 -0.7 0
2 Modeling location. K-factor assumed to be the same as for Receiver 1 0
3 Modeling location. K-factor assumed to be the same as for Receiver 1 0
4 Modeling location. K-factor assumed to be the same as for Receiver 5 1.7
5 64.9 1 63.2 1 1.7 1.7
6 Modeling location. K-factor assumed to be the same as for Receiver 5 1.7
7 Modeling location. K-factor assumed to be the same as for Receiver 5 1.7
8 Modeling location. K-factor assumed to be the same as for Receiver 12 0
9 Modeling location. K-factor assumed to be the same as for Receiver 12 0
10 Modeling location. K-factor assumed to be the same as for Receiver 12 0
11 Modeling location. K-factor assumed to be the same as for Receiver 12 0
122 61.1 1 60.8 0.3 0
13 Modeling location. K-factor assumed to be the same as for Receiver 12 0
14 56.6 57.7 -1.1 -1.1
15 59.1 58.1 1.0 1.0
Notes:
1. Per Caltrans Technical Noise Supplement [Reference 3], Section N-5460, no calibration has been used
when calculated and measured noise levels agree within 1 dBA.
2. A noise measurement was attempted at Receiver 12 (4142 Crabapple Court) on February 7, 2008.
However, reliable data was not obtained due to extraneous noise from a nearby fountain. Therefore,
this measurement was excluded from the study and could not be used to calibrate the TNM model.
Instead, the data gathered during the corresponding hour of the day(7 a.m. to 8 a.m.) from the August
2007 measurements was used to verify the accuracy of the model at the south end of the study area.
It is noted that that the K-factors in the above table are for the calibration hour(7 a.m.to 8 a.m.). In
order to estimate the peak noise hour levels(6 a.m.to 7 a.m.) an additional 0.7 dB has been added at
each receiver to account for the difference in levels between the two hours.This additional
adjustment represents the average difference in noise levels between the 6 a.m.to 7 a.m.and 7 a.m. to
8 a.m.periods at Receivers 1 and 5.
, a G7
APPENDIX D
Calculation of Future Peak Noise Hour Levels
Notes:
The geometric data and calibration factors(K-factors)used in the future peak noise model are the
same as those used the calibration model.As this data is provided in full in Appendix C,it is not
repeated here. However,the TNM traffic data was changed for the future peak noise hour case and
has,therefore,been included in this appendix.
' 0 077
APPENDIX E
Sound Wall Analysis
Notes:
The following geometric data used in the sound wall analysis is the same as that used the calibration
model: roadways,receivers,terrain lines and ground zones.As this geometric data is provided in full
in Appendix C,it is not repeated here. However,the addition of the sound wall to the model altered
the barrier geometry data;therefore,the updated barrier geometry data has been included in this
appendix.
The TNM traffic data used in the sound wall analysis is the same as for the future peak noise hour
case. As this traffic data is provided in full in Appendix C,it is not repeated here.
r—�
0.41W'� d
APPENDIX F
Geometric Data for Sound Wall SW-1
Coordinates
zo(Base of wan z, (Top of Wall
X(Easting) Y(Northing) Elevation) Elevation)
M m m m
1,921,310.0 585,789.6 219.5 223.8
1,921,343.8 585,735.7 218.1 222.3
1,921,356.3 585,715.0 217.2 221.5
1,921,382.4 585,666.6 215.7 220.0
1,921,403.7 585,626.9 214.2 218.5
1,921,424.1 1 585,589.0 212.1 216.4
Data is provided in metric units to correspond with the metric coordinate system used in the
referenced DXF plans.