Campbell Avenue Mixed Use Environmental Noise Analysis

Prepared for:

Attn: Deana EllisVice President Land Resources1031 Junction Boulevard, Suite 808Roseville, CA 95678

Prepared by:

j.c. brennan & associates, Inc.

Jim Brennan, INCE PresidentMember, Institute of Noise Control Engineering (INCE)

Campbell Avenue Mixed UseEnvironmental Noise Analysis

May 1, 2018

jcb Project # 2018-131

1287 High Street, Auburn, California 95603 * 530-823-0960 (p) * (530)823-0961 (f)

j.c. brennan & associates, Inc. Job # 2018-131

Environmental Noise Analysis Revised Campbell Avenue Mixed Use – City of Campbell, California

Page 1 of 16

1. INTRODUCTION The City of Campbell has received a proposal from Cresleigh Homes to construct mixed use development which includes approximately 8,000 square feet of commercial on the ground floor, subterranean parking, and 81 residential units. The project site also has a roof-top terrace which is considered to be the common outdoor activity area for the residential portion of the project. The project site is located on seven parcels bounded by Campbell Avenue to the north, Dillon Avenue to the west, and Gilman Avenue to the east. Figure 1 shows the project location. Figure 2 shows the project site plan. Figure 3 shows the project elevation from Campbell Avenue. The potential noise sources which were identified which may affect the project design, included traffic on Campbell Avenue to the north and S.R. 17 to the east, and the railroad line to the west. Noise sources associated with the project which could impact adjacent residences included truck deliveries, mechanical equipment, the roof-top terrace, and construction activities. The purpose of this analysis is to analyze environmental noise sources, and to determine if the project complies with the exterior and interior noise level standards established by the City of Campbell. ENVIRONMENTAL SETTING Noise Background Acoustics is the science of sound. Sound may be thought of as mechanical energy of a vibrating object transmitted by pressure waves through a medium to human (or animal) ears. If the pressure variations occur frequently enough (at least 20 times per second), then they can be heard and are called sound. The number of pressure variations per second is called the frequency of sound, and is expressed as cycles per second or Hertz (Hz). Noise is a subjective reaction to different types of sounds. Noise is typically defined as (airborne) sound that is loud, unpleasant, unexpected or undesired, and may therefore be classified as a more specific group of sounds. Perceptions of sound and noise are highly subjective. Often, someone’s music is described as noise by another. Measuring sound directly in terms of pressure would require a very large and awkward range of numbers. To avoid this, the decibel scale was devised. The decibel scale uses the hearing threshold (20 micropascals), as a point of reference, defined as 0 dBA. Other sound pressures are then compared to this reference pressure, and the logarithm is taken to keep the numbers in a practical range. The decibel scale allows a million-fold increase in pressure to be expressed as 120 dBA, and changes in levels (dBA) correspond closely to human perception of relative loudness.

Campbell Avenue Mixed UseFigure 1: Project Area Plan

Rev. 09/15/16

A

1

2

Continuous 24-hour Noise Monitoring Site

Short-term Noise Monitoring Sites

Figure 2

Site Plan

Rev. 1/11/17

Project Site

Figure 3

Elevation

Rev. 1/11/17

Project Site



Page 5 of 16

The perceived loudness of sounds is dependent upon many factors, including sound pressure level and frequency content. However, within the usual range of environmental noise levels, perception of loudness is relatively predictable, and can be approximated by A-weighted sound levels.

There is a strong correlation between A-weighted sound levels (expressed as dBA) and the way the human ear perceives sound. For this reason, the A-weighted sound level has become the standard tool of environmental noise assessment. All noise levels reported in this section are in terms of A-weighted levels, but may be expressed as dBA, unless otherwise noted.

The decibel scale is logarithmic, not linear. In other words, two sound levels 10 dBA apart differ in acoustic energy by a factor of 10. When the standard logarithmic decibel is A-weighted, an increase of 10 dBA is generally perceived as a doubling in loudness. For example, a 70 dBA sound is half as loud as an 80 dBA sound, and twice as loud as a 60 dBA sound.

Community noise is commonly described in terms of the ambient noise level, which is defined as the all-encompassing noise level associated with a given environment. A common statistical tool to measure the ambient noise level is the average, or equivalent, sound level (Leq), which corresponds to a steady-state A weighted sound level containing the same total energy as a time varying signal over a given time period (usually one hour). The Leq is the foundation of the composite noise descriptor, Ldn, and shows very good correlation with community response to noise.

The day/night average level (Ldn) is based upon the average noise level over a 24-hour day, with a +10 decibel weighing applied to noise occurring during nighttime (10:00 p.m. to 7:00 a.m.) hours. The nighttime penalty is based upon the assumption that people react to nighttime noise exposures as though they were twice as loud as daytime exposures. Because Ldn represents a 24-hour average, it tends to disguise short-term variations in the noise environment.

Table 1 lists several examples of maximum noise levels associated with common noise sources.

Effects of Noise on People

The effects of noise on people can be placed in three categories:

Subjective effects of annoyance, nuisance, and dissatisfaction

Interference with activities such as speech, sleep, and learning

Physiological effects such as hearing loss or sudden startling

Environmental noise typically produces effects in the first two categories. Workers in industrial plants can experience noise in the last category. There is no completely satisfactory way to measure the subjective effects of noise or the corresponding reactions of annoyance and



Page 6 of 16

dissatisfaction. A wide variation in individual thresholds of annoyance exists and different tolerances to noise tend to develop based on an individual’s past experiences with noise.

Thus, an important way of predicting a human reaction to a new noise environment is the way it compares to the existing environment to which one has adapted: the so-called ambient noise level. In general, the more a new noise exceeds the previously existing ambient noise level, the less acceptable the new noise will be judged by those hearing it.

With regard to increases in A-weighted noise level, the following relationships occur:

Except in carefully controlled laboratory experiments, a change of 1 dBA cannot be perceived;

Outside of the laboratory, a 3 dBA change is considered a just-perceivable difference;

A change in level of at least 5 dBA is required before any noticeable change in human response would be expected; and

A 10 dBA change is subjectively heard as approximately a doubling in loudness, and can cause an adverse response.

Stationary point sources of noise – including stationary mobile sources such as idling vehicles – attenuate (lessen) at a rate of approximately 6 dBA per doubling of distance from the source, depending on environmental conditions (i.e. atmospheric conditions and either vegetative or manufactured noise barriers, etc.). Widely distributed noises, such as a large industrial facility spread over many acres, or a street with moving vehicles, would typically attenuate at a lower rate.

A complete listing of acoustical terminology is provided in Appendix A.



Page 7 of 16



Page 8 of 16

2. CRITERIA FOR ACCEPTABLE NOISE AND VIBRATION EXPOSURE1

State of California

The State Building Code, Title 24, Part 2 of the State of California Code of Regulations establishes uniform minimum noise insulation performance standards to protect persons within new buildings which house people, including hotels, motels, dormitories, apartment houses and dwellings other than single-family dwellings. Title 24 mandates that interior noise levels attributable to exterior sources shall not exceed 45 dB Ldn or CNEL in any habitable room. Title 24 also mandates that for structures containing noise-sensitive uses to be located where the Ldn or CNEL exceeds 60 dB, an acoustical analysis must be prepared to identify mechanisms for limiting exterior noise to the prescribed allowable interior levels. If the interior allowable noise levels are met by requiring that windows be kept close, the design for the structure must also specify a ventilation or air conditioning system to provide a habitable interior environment. City of Campbell Noise Element Noise Level Criteria The City of Campbell Noise Element (As contained in the Conservation and Natural Resources Element) of the General Plan establishes noise level standards for new developments. The following are the pertinent Goals, Policies and Strategies for new developments. Goal CNR-10: Protect the community, especially sensitive noise receptors such as schools, hospitals and senior facilities from excessive noise. Policy CNR-10.1: Noise Reduction: Reduce noise levels at the source.

Strategy CNR-10.1b: Minimization of Noise Exposure and Generation: Encourage practices and technologies that minimize noise exposure and noise generation in new development and redevelopment. Strategy CNR-10.1c: Noise and New Development: Evaluate the potential for noise pollution and ways to reduce noise impacts when reviewing development proposals. Noise from Stationary Sources: New residential development shall conform to a stationary source noise exposure standard of 65 dBA for exterior noise levels and 45 dBA for interior noise levels. Acoustical studies shall be required for all new noise-sensitive projects that may be affected by existing noise from stationary sources. Where existing stationary noise sources exceed the City's noise standards, mitigation measures

1 For an explanation of these terms, see Appendix A: "Acoustical Terminology"



Page 9 of 16

shall be implemented to reduce noise exposure to or below the allowable levels of the Noise Ordinance. Traffic Related Noise: New residential development shall conform to a traffic-related noise exposure standard of 60 dBA CNEL for outdoor noise in noise-sensitive outdoor activity areas and 45 dBA CNEL for indoor noise. New development which does not and cannot be made to conform to this standard shall not be permitted. Acoustical studies, describing how the exterior and interior noise standards will be met, shall be required for all new residential developments with a noise exposure greater than 60 dBA CNEL. The studies should also satisfy the requirements set forth in Title 24, Part 2, of the California Administrative Code, Noise Insulation Standards for multiple-family attached residential projects, hotels, motels, etc., regulated by Title 24. Table CNR-2:P Traffic-Related Noise Conditions at General Plan Buildout should be used as the basis to initially identify areas with potential excessive noise exposure. Strategy CNR-10.1d: Noise Mitigation Measures: Review and require noise mitigation measures for development projects, including setbacks between uses, earth berms, sound walls, landscaping and site design that shields noise-sensitive uses with non-sensitive structures such as parking lots, utility areas and garages, or orients buildins to shield outdoor spaces from noise sources. Strategy CNR-10.1e: Construction Noise Mitigation: Require mitigation measures during construction, including limits on operating times of noise-producing activities (including vehicles). Strategy CNR-10.1f: Sound Walls: In cases where sound walls are used as mitigation, they should be encouraged to help create an attractive setting with features such as setbacks, changes in alignment, detail and texture, pedestrian access (if appropriate) and landscaping. Strategy CNR-10.1-j: Truck Traffic Limits: Limit commercial, industrial and construction truck traffic in residential areas.

City of Campbell Municipal Code 18.04.052 The Campbell municipal codes regulates the hours of construction. Construction activity for homeowners working on their own property is allowed Monday through Saturday, 6 am to 7 pm; Sundays and Holidays, 8 am to 6 pm. Construction hours for non-homeowners are Monday through Friday, 8 am to 5 pm, Saturdays, 9 am to 4 pm and no construction Sundays and Holidays.



Page 10 of 16

3. SETTING AND IMPACT EVALUATION

Ambient Noise Levels in the Project Vicinity The existing noise environment at the project site is defined primarily by the roadway traffic associated with Campbell Avenue, and distant traffic noise associated with S.R. 17. Based upon field observations, and the noise measurement data described below, the primary noise source at the project site is Campbell Avenue traffic. Observations indicated that S.R. 17 was shielded by topography and intervening building facades. The Santa Clara Valley Transportation Authority (VTA) operates light rail on the Mountain View to Winchester line which is approximately 550-feet from the project site. Measured noise levels for the light rail operations are discussed later in this report. However, it is noted that the light rail noise levels are not significant at the project site.

j.c. brennan & associates, Inc. conducted continuous hourly ambient noise level measurements for a period of 24-hours on the project site on September 28th and 29th, 2016 (See Figure 1 for the location of the noise measurement sites) to determine typical background average (Leq), median (L50) and maximum (Lmax) noise levels, and to determine the effective day/night distribution of roadway traffic for inclusion in the traffic noise prediction methodology. Instrumentation consisted of a Larson Davis Laboratories (LDL) Model 820 precision integrating sound level meter, which was calibrated in the field before and after use with an LDL Model CAL200 acoustical calibrator.

Table 2 shows the results of the ambient noise level measurements. Appendix B graphically shows the results of the noise level measurements. On Wednesday September 21st, j.c. brennan & associates, Inc., staff conducted short-term noise level measurements at the project site. Table 3 shows the results of the short-term noise measurements. Appendix B also provides the graphical results of the short-term noise measurements.

TABLE 2

SUMMARY OF MEASURED AMBIENT NOISE LEVELS

SEPTEMBER 28TH – 29TH, 2016

Average Hourly Daytime & Evening (7:00am - 10:00pm)

Average Hourly Nighttime (10:00pm – 7:00am)

Site

Measured

CNEL Leq L50 Lmax Leq L50 Lmax

A 59 dBA 60 dBA 55 dBA 69 dBA 49 dBA 45 dBA 65 dBA

Source: j.c. brennan & associates, Inc. - 2016



Page 11 of 16

TABLE 3

SUMMARY OF SHORT TERM NOISE LEVEL MEASUREMENTS

SEPTEMBER 21, 2016

Measured Sound Level Site Location Time1

Leq L50 Lmax

Notes

1 55-feet from Campbell

Avenue Centerline 2:40 pm 66 dBA 64 dBA 80 dBA

Campbell Avenue is the primary

noise source

2 Near Gilman Avenue 1:15 pm 60 dBA 58 dBA 72 dBA Campbell Avenue and S.R. 17 are

the audible noise sources.

1 - All Community Noise Measurement Sites have a test duration of 10:00 minutes. Source - j.c. brennan & associates, Inc. 2016.

Future Exterior Traffic Noise Levels j.c. brennan & associates, Inc. employs the Federal Highway Administration (FHWA) Traffic Noise Prediction Model (FHWA RD-77-108) for the prediction of traffic noise levels. The model is based upon the CALVENO noise emission factors for automobiles, medium trucks and heavy trucks, with consideration given to vehicle volume, speed, roadway configuration, distance to the receiver, and the acoustical characteristics of the site. Based upon the traffic volumes for future conditions as provided by the City of Campbell Table CNR-2 "Traffic Noise Conditions at General Plan Buildout", and Caltrans reported traffic volumes, the future traffic noise levels at the project site were determined using the FHWA traffic noise prediction model. The predicted noise level at the project site and the distances to the traffic noise contours are shown in Table 4.

TABLE 4

PREDICTED FUTURE TRAFFIC NOISE LEVELS

Distance to Noise Contours

Roadway Traffic Noise Level, CNEL 60 dB Ldn 65 dB Ldn

S.R. 17

Campbell Avenue

63 dBA CNEL @ 800-feet

64 dBA CNEL @ 75-feet

1,386-feet 144-feet

643-feet 67-feet

Sources: j.c. brennan & associates, Inc., and FHWA RD-77-108 - 2018



Page 12 of 16

Based upon Table 4, the future Campbell Avenue and S.R. 17 traffic noise levels will exceed the 60 dB CNEL exterior noise level standard at the nearest apartment building facades and the roof-top courtyard area. Based upon the project design, the roof parapet is 3-1/2-feet in height, and will provide some shielding of noise levels due to roadway traffic. A barrier analysis was conducted to determine the required barrier height (including the proposed parapet) to reduce traffic noise levels to less than 60 CNEL at the roof-top courtyard. The analysis factored in the relative roadway elevations and the predicted traffic noise levels. Table 5 shows the results of the barrier analysis.

TABLE 5

REQUIRED BARRIE HEIGHT TO REDUCE TRAFFIC NOISE LEVELS

Roadway Predicted

Traffic Noise Level

Required

Barrier Height

Mitigated

Traffic Noise Level

S.R. 17 63 dB CNEL 5-1/2 feet 58 dB CNEL

Cambell Avenue 64 dB CNEL 5-1/2 feet 53 dB CNEL

Cumulative Traffic Noise Level 59 dB CNEL

Source: j.c. brennan & associates, Inc. - 2018

Based upon the results of the barrier analysis shown in Table 5 (Appendix C), the parapet at the roof-top courtyard would need to be raised an additional 2-feet at the facades facing Campbell Avenue and S.R. 17. This can be done with the building facade materials, or a plexiglass which has a density of 2-1/2 lbs./square foot. The increased parapet would need to be solid, and without gaps to allow flanking of the traffic noise. Future Interior Traffic Noise Levels As a means of determining the ability of the project to achieve the interior noise level criterion of 45 dBA CNEL, interior noise level calculations were conducted. To judge the potential for achieving an interior noise level of 45 dBA CNEL, it is necessary to determine the noise reduction provided by the building wall facades. This may be calculated by assuming a generalized A-weighted noise frequency spectrum for the roadway noise. The composite transmission loss and resulting noise level in the receiving room is first determined. After correcting for room absorption, the overall noise level in the room is calculated. The building construction is assumed to be either wood or metal frame, with a minimum of R-19 insulation in the stud cavities and R-38 in the attic spaces, stucco siding is on the exterior with 1/2" gypsum board on the interior.



Page 13 of 16

Using the procedure described above, Table 6 shows the results of the interior noise calculations for the nearest units which have a noise exposure to two wall facades. A +3 dBA correction factor was added to ensure variations in construction would ensure compliance with the standard. Appendix D provides the calculation inputs for a typical bedroom or living room.

Table 6 Calculated Interior Noise Levels

Exterior Noise Levels Interior Noise Levels

Room Parallel Wall

Exterior Perpendicular Wall

Exterior Cumulative

Interior Living / Bedroom with Typical Dual Glazed Windows and Sliding Glass Doors 65 dBA CNEL 65 dBA CNEL

45 dBA CNEL

Source: j.c. brennan & associates, Inc., 2016

Based upon Table 6, and the calculation procedure discussed above, typical dual glazed windows and sliding glass doors will achieve the interior noise level standard of 45 dB CNEL. Appendix D includes the interior calculations for the interior Ldn standard. Railroad Noise Levels

j.c. brennan & associates, Inc. conducted noise level measurements of VTA light rail operations west of the project site. To determine the overall CNEL due to light rail operations, the sound level meter collects the Sound Exposure Level (SEL) for each light rail passby. The measured SEL's account for the sound energy during each train pass-by, and the overall duration (number of seconds) of the train event. The SEL essentially compresses all of the sound energy during the entire event into 1 second. In general, the measured SEL due to a train pass-by is approximately 10 dB higher than the measured maximum noise level. Figure 4 shows the relationship between a maximum noise level and an SEL. Figure 4 is based upon an aircraft overflight, however, it is the same principle for a train pass-by.

The average SEL due to the train passbys was 85 dBA at a distance of 50-feet. Based upon the VTA schedule, there are a total of 120 light rail operations during the typical weekday. There are a total of 96 daytime (7 a.m. to 10 p.m.) operations, and 24 nighttime (10 p.m. to 7 a.m.) operations. Nighttime operations are penalized by a factor of 10 times. Therefore, the equivalent number of operations are 336 (24*10 nighttime + 96 daytime). The formula for determining the Ldn/CNEL is as follows:

CNEL/Ldn = SEL + (10 * the logarithm of 336) - 49.4, where:

The measured SEL was 85 dBA @ 50-feet, and 10 times the logarithm of 336 is 25.3, and 49.4 is times the logarithm of the number of seconds in a day.



Page 14 of 16

The CNEL/Ldn at 50-feet is 61 dBA. The project site is approximately 550-feet from the light rail line. The predicted CNEL/Ldn at the site is 45 dBA.

Figure 4

Future Construction Noise Levels Construction of the Proposed Project would temporarily increase noise levels during construction. During the construction phases of the project, noise from construction activities would add to the noise environment in the immediate project vicinity. Activities involved in construction would generate maximum noise levels, as indicated in Table 7, ranging from 76 to 88 dB at a distance of 50 feet. Construction activities would be temporary in nature and are anticipated to occur during normal daytime working hours.



Page 15 of 16

Table 7 Construction Equipment Noise

Predicted Noise Levels, Lmax dB Distances to Noise Contours

(feet)

Type of Equipment Noise

Level at 50’

Noise Level at

100’

Noise Level at

200’

Noise Level at

400’

70 dB Lmax

contour 65 dB Lmax

contour

Backhoe 78 72 66 60 126 223 Compactor 83 77 71 65 223 397

Compressor (air) 78 72 66 60 126 223 Dozer 82 76 70 64 199 354

Dump Truck 76 70 64 58 100 177 Excavator 81 75 69 63 177 315 Generator 81 75 69 63 177 315

Pneumatic Tools 85 79 73 67 281 500

Source: Roadway Construction Noise Model User’s Guide. Federal Highway Administration. FHWA-HEP-05-054. January 2006.

The Campbell Municipal Code regulates the hours of construction. Construction activity for homeowners working on their own property is allowed Monday through Saturday, 6 am to 7 pm; Sundays and Holidays, 8 am to 6 pm. Construction hours for non-homeowners are Monday through Friday, 8 am to 5 pm, Saturdays, 9 am to 4 pm and no construction Sundays and Holidays. Commercial Noise Source Impacts Since this is a mixed use development, It would be difficult to apply the standards of 65 dBA at exterior spaces and 45 dBA for interior spaces at the property line of the residential component of the project. The primary noise sources associated with commercial uses include delivery trucks, mechanical air handling equipment. It is recommended that commercial use mechanical equipment is mounted inside a mechanical room or shielded from residences. Deliveries should be confined to the daytime hours between 7:00 a.m. and 7:00 p.m. Roof-top Courtyard Noise Impacts Noise levels associated with the roof-top Courtyard area would result from groups of individuals talking in various voice levels. Generally, groups of 10 to 15 adults carrying on conversations at normal and raised voice levels range between 50 dB Leq and 60 dB Leq, at a distance of 50-feet. Noise levels at adjacent residences are not expected to exceed the 65 dB stationary noise source standard. However, some on-site residences will be closer than 50-feet, and may exceed the exterior stationary noise source standard of 65 dB. The following recommendations will assist in reducing noise from the roof-top courtyard to within acceptable levels: Construct a wall or add to the parapet to achieve the 5-1/2 foot barrier between the

courtyard and the adjacent on-site residences;



Page 16 of 16

Restrict the use of amplified music or voices at the courtyard. Any special event planned

in the courtyard will require approval from the manager and notification of any residences within 200-feet;

Restrict the use of the roof-top courtyard to the hours of 7:00 a.m. to 10:00 p.m.

4. CONCLUSIONS AND RECOMMENDATIONS The project will comply with the City of Campbell noise level criteria, provided the following recommendations are included in the project design: 1. As a means of complying with the 60 dB CNEL exterior noise level standard at the roof-

top courtyard, the parapet at the roof-top courtyard would need to be raised an additional 2-feet (a total of 5-1/2 feet) at the facades facing Campbell Avenue and S.R. 17. This can be done with the building facade materials, or a plexiglass which has a density of 2-1/2 lbs./square foot. The increased parapet would need to be solid, and without gaps to allow flanking of the traffic noise.

2. Windows and sliding glass doors should be typical dual glazed with a minimum STC

rating of 28; 3. Residential units should include air conditioning units to allow resident's to close

windows and doors for acoustical isolation; 4. Construction activities need to comply with the municipal code time of day restrictions; 5. It is recommended that mechanical equipment associated with commercial uses, which

is used for air conditioning is mounted inside a mechanical room or shielded from adjacent residences. Deliveries should be confined to the daytime hours between 7:00 a.m. and 7:00 p.m;

6. Construct a wall or add to the parapet to achieve the 5-1/2 foot barrier between the roo-

top courtyard and the adjacent on-site residences; 7. Restrict the use of amplified music or voices at the courtyard. Any special event planned

in the courtyard will require approval from the manager and notification of any residences within 200-feet;

8. Restrict the use of the roof-top courtyard to the hours of 7:00 a.m. to 10:00 p.m.

Appendix A Acoustical Terminology

Acoustics The science of sound. Ambient Noise The distinctive acoustical characteristics of a given space consisting of all noise sources audible at

that location. In many cases, the term ambient is used to describe an existing or pre-project condition such as the setting in an environmental noise study.

Attenuation The reduction of an acoustic signal. A-Weighting A frequency-response adjustment of a sound level meter that conditions the output signal to

approximate human response. Decibel or dB Fundamental unit of sound, A Bell is defined as the logarithm of the ratio of the sound pressure

squared over the reference pressure squared. A Decibel is one-tenth of a Bell. CNEL Community Noise Equivalent Level. Defined as the 24-hour average noise level with noise occurring

during evening hours (7 - 10 p.m.) weighted by a factor of three and nighttime hours weighted by a factor of 10 prior to averaging.

Frequency The measure of the rapidity of alterations of a periodic signal, expressed in cycles per second or

hertz. Ldn Day/Night Average Sound Level. Similar to CNEL but with no evening weighting. Leq Equivalent or energy-averaged sound level. Lmax The highest root-mean-square (RMS) sound level measured over a given period of time. L(n) The sound level exceeded a described percentile over a measurement period. For instance, an hourly

L50 is the sound level exceeded 50% of the time during the one hour period. Loudness A subjective term for the sensation of the magnitude of sound. Noise Unwanted sound. Peak Noise The level corresponding to the highest (not RMS) sound pressure measured over a given period of

time. This term is often confused with the AMaximum@ level, which is the highest RMS level. RT60 The time it takes reverberant sound to decay by 60 dB once the source has been removed. Sabin The unit of sound absorption. One square foot of material absorbing 100% of incident sound has an

absorption of 1 sabin. Threshold of Hearing The lowest sound that can be perceived by the human auditory system, generally considered to be 0

dB for persons with perfect hearing. Threshold of Pain Approximately 120 dB above the threshold of hearing. Impulsive Sound of short duration, usually less than one second, with an abrupt onset and rapid decay. Simple Tone Any sound which can be judged as audible as a single pitch or set of single pitches.

Project #:Description:Ldn/CNEL: CNELHard/Soft: Soft

Segment Roadway Name ADT Day % Eve % Night %% Med. Trucks

% Hvy. Trucks Speed Distance

Offset (dB)

1 S.R. 17 143,000 85 5 10 1 3 60 8202 Campbell Ave 27,667 85 5 10 1 1 30 75345678910111213141516171819202122232425

Appendix B

2018-131

Segment Description

FHWA-RD-77-108 Highway Traffic Noise Prediction Model

Cambell Avenue Mixed Use

Data Input Sheet

At the project site At the project site

Project #:Description:Ldn/CNEL:Hard/Soft:

Medium HeavySegment Roadway Name Autos Trucks Trucks Total

1 S.R. 17 61.9 49.0 57.4 632 Campbell Ave 61.8 52.7 59.8 64

Appendix B

2018-131

CNELSoft


Segment Description

FHWA-RD-77-108 Highway Traffic Noise Prediction ModelPredicted Levels


Project #:Description:Ldn/CNEL:Hard/Soft:

Segment Roadway Name 75 70 65 60 55

1 S.R. 17 139 299 643 1386 29862 Campbell Ave 14 31 67 144 311


Segment Description-------- Distances to Traffic Noise Contours --------

CNELSoft

FHWA-RD-77-108 Highway Traffic Noise Prediction ModelNoise Contour Output

Appendix B

2018-131


62

49

57

795

25

2062082142202252206

Autos

Medium Trucks

Heavy Trucks Total Autos?

Medium Trucks?

Heavy Trucks?

6 56 44 52 58 Yes Yes Yes7 56 43 51 57 Yes Yes Yes8 55 42 51 56 Yes Yes Yes9 54 41 50 55 Yes Yes Yes10 53 40 49 54 Yes Yes Yes11 52 39 48 54 Yes Yes Yes12 51 38 47 53 Yes Yes Yes13 51 38 47 52 Yes Yes Yes14 50 37 46 52 Yes Yes Yes

Notes:

At the project site

227228

Receiver Description:

Medium Truck Elevation:Heavy Truck Elevation:

Receiver Elevation1:

Automobile Elevation:

226

2018-131

Barrier Breaks Line of Sight to…

Roadway Name:

Year:


Heavy Truck Ldn, dB:

Medium Truck Ldn, dB:

Centerline to Barrier Distance (C1):

Barrier to Receiver Distance (C2):

Pad/Ground Elevation at Receiver:

Base of Barrier Elevation:Starting Barrier Height

-------------------- Ldn, dB --------------------Barrier

Height2 (ft)

1.Standard receiver elevation is five feet above grade/pad elevations at the receiver location(s)

Barrier Effectiveness:

234

229230231232

Top of Barrier

Elevation (ft)

233

Project Information:

Noise Level Data:

Site Geometry:

S.R. 171Location(s):

Auto Ldn, dB:2025

Job Number:Description

Noise Barrier Effectiveness Prediction WorksheetFHWA Traffic Noise Prediction Model (FHWA-RD-77-108)Appendix C

62

53

60

50

25

2002022082202252206

Autos

Medium Trucks

Heavy Trucks Total Autos?

Medium Trucks?

Heavy Trucks?

6 49 41 49 52 Yes Yes Yes7 49 40 48 52 Yes Yes Yes8 48 39 48 51 Yes Yes Yes9 47 39 47 50 Yes Yes Yes10 47 38 46 50 Yes Yes Yes11 47 38 46 49 Yes Yes Yes12 46 37 45 49 Yes Yes Yes13 46 37 45 49 Yes Yes Yes14 46 36 45 48 Yes Yes Yes

Notes:

Noise Barrier Effectiveness Prediction WorksheetFHWA Traffic Noise Prediction Model (FHWA-RD-77-108)Appendix C

Job Number:Description

Roadway Name:

2018-131

-------------------- Ldn, dB --------------------

1.Standard receiver elevation is five feet above grade/pad elevations at the receiver location(s)

Project Information:

Noise Level Data:

Site Geometry:

Campbell Ave2Location(s):

Auto Ldn, dB:2025

Automobile Elevation:

Barrier Breaks Line of Sight to…

At the project site Centerline to Barrier Distance (C1):

Barrier to Receiver Distance (C2):

Pad/Ground Elevation at Receiver:

Barrier Effectiveness:

Base of Barrier Elevation:Starting Barrier Height

Year:


Heavy Truck Ldn, dB:

Medium Truck Ldn, dB:

234

229230231232

227228

Receiver Description:

233

226

Top of Barrier

Elevation (ft)

Barrier

Height2 (ft)

Medium Truck Elevation:Heavy Truck Elevation:

Receiver Elevation1:

Campbell Avenue Mixed Use Environmental Noise Analysis

Documents

Transcript of Campbell Avenue Mixed Use Environmental Noise Analysis