HomeMy WebLinkAboutCDP 00-16; POINSETTIA LANE REACH E; NOISE ASSESSMENT; 1999-08-19Engineering, Planning,
Corporate Office:
Environmental Sciences and
& ASSOCIATES, INC. 605 Third Street
Professional Teams for Complex Projects Management Services Encnitas, CaIfornia 92024
August 19, 1999
760.942.5147
Fax 760.632.0164
2320-01
Mr. Ray Martin
Htinsaker & Associates
10179 Huennekens Street
San Diego, CA 92121 -
PROJECT: Poinsettia Lane (Reach E) Project--Carlsbad, CA
RE: Noise Assessment
Dear Mr. Martin:
DUDEK & Associates, Inc., has evaluated the potential noise impacts associated with the proposed
Poinsettia Lane project located in the City of Carlsbad. In summary, there is one existing home
: within the project vicinity. The future noise level at this home would be less than 60 dB CNEL and
will meet the City's noise criteria.
1.0 BACKGROUND
The City of Carlsbad has requested that an acoustical analysis be prepared assessing future traffic
noise along the extension of Poinsettia Lane (beginning at approximately Station 177 and ending at
Station 196). This noise assessment evaluates traffic noise from the existing eastern terminus of
Poinsettia Lane to a location approximately 1,900 linear feet east of the existing terminus (Figure 1).
There are no existing residences immediately adjacent to the proposed alignment. One single family
residence is located approximately 650 feet northeast from the proposed center line alignment. This
noise assessment is based on the .prelminary alignment plans for Poinsettia Lane (Hunsaker &
Associates July 15, 1999).
l .. City Exterior Noise Criteria
The City of Carlsbad requires that exterior noise levels not exceed a Community Noise Equivalent
Level (CNEL) of 60 dB and interior noise levels not exceed 45 dB CNEL. All sound levels discussed
in this report are A-weighted. Acoustical terminology used in this report is contained in Appendix 1.
1.2 Methodology
The traffic noise analysis methodology follows the City's noise assessment methodology documented
in the City's Noise Guidelines Manual (City of Carlsbad, 199.5). The future noise level along
t
if
Poinsettia Lane (Reach E) Noise Assessment I FIGURE I
Vicinity Location Map 1
Poinsettia Lane (Reach E) Project• Noise Assessment
Poinsettia Lane was determined using Caltrans' SOUND32 Highway Traffic Noise Prediction Model
(Caltrans, 1983) with California noise emission factors (Caltrans, 1987). The noise model is based
on the Federal Highway Administration's traffic noise prediction model (FHWA, 1972). Input used
in the noise model included the buildout traffic volume of 14,100 average daily traffic (ADT) with
vehicle speeds of 40 mph along Poinsettia Lane. This vehicle speed is based on the existing posted
speed limit along Poinsettia Lane west of the project site. The truck mix used was 1.83 percent
medium trucks and 0.28 percent heavy trucks. The truck mix is based on vehicle mix surveys
conducted by the City. Traffic .rolume was provided by the City's traffic engineering department
(City of Carlsbad 1999).
2.0 NOISE ASSESSMENT
There are no existing homes that would be located • immediately adjacent to the proposed road
alignment. One existing home is located approximately 650 feet northeast of the limits of the
proposed extension of Poinsettia Lane. The future CNEL at the backyard of this home will be less
than 60 dB. This noise level will comply with the City's exterior noise criteria.
The CNEL at the facade of the home facing Poinsettia Lane will be less than 60 dB. Typically, with
the windows' open, and using standard California construction materials and methods, the building
shells provide approximately 15 dB of noise reduction. Therefore, residences exposed to an exterior
CNEL greater than 60 dB could result in an interior CNEL greater than 45 dB. The exterior noise level
would be less than 60 dB at the residence. Therefore, the interior noise level would be 45 dB or less.
This noise level would comply with the City's interior noise guideline.
3.0 CONCLUSIONS
The proposed project would not result in significant noise impact at any existing residences,
therefore, noise mitigation measures have not been recommended.
This concludes our noise assessment. If you have any questions, please call me.
Very truly yours,
DUDE( &ASSOCIATES, INC
.&
Mik'e KomA
Acoustician
& ASSOCIATES, INC. 2320-01
IoThfCp&.j August 19, 1999 3
Poinsettia Lane (Reach E) Project• Noise Assessment
REFERENCES
California Department of Transportation (Caltrans), June 1988. User's Instructions for SOUND32
(FHWA/CA-83/06).
California Department of Transportation (Caltrans), 1987. California Vehicle Noise Emission Levels,
(FI-IWA/CA/TL-87103).
Carlsbad, City of, September, 1995. City of Carlsbad Noise Guidelines Manual.
Carlsbad, City of, August 13, 1999. Telephone conversation with Mr. Jim Murray, Traffic Engineering
Department.
Federal Highway Administration (FHWA), 1978. FHWA Highway Traffic Noise Prediction Model
(FHWA-RD-77-108).
2320-01
August 19, 1999 4
ATTACHMENT 1
DEFINITIONS
Term Definition
Ambient Noise Level •The composite of noise from all sources near and far.
The normal or existing level of environmental noise at
a given location.
A-Weighted Sound Level, (dB(A)) The sound pressure level in decibels as measured on a
sound level meter using the A-weighted filter network.
The A-weighting filter de-emphasizes the very low
and very high frequency components of the sound in
a manner similar to the frequency response of the
human ear and correlates well with subjective
reactions to noise.
Community Noise Equivalent Level CNEL is the A-weighted equivalent continuous sound
exposure level for a 24-hour period with a ten dB
adjustment added to sound levels occurring during
nighttime hours (10 pm to 7 am) and a five dB
adjustment added to the sound levels occurring during
the evening hours (7 pm to 10 pm).
Decibel, (dB) . A unit for measuring sound pressure level, equal to
10 times the logarithm to the base 10 of the ratio of
the measured sound pressure squared to a reference
pressure, which is 20 micropascals.
Maximum A-Weighted Sound Level. The greatest sound level measured on a sound level
meter during a designated time interval or event using
fast time-averaging (125-ms) and A-weighting.
Time-Average Sound Level, (TAV) The sound level corresponding to a steady state sound
level containing the same total energy as a time
varying signal over a given sample period. TAV is
designed to average all of the loud and quiet sound
levels occurring over a specific time period.
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