1、Standard Method of Test for Determining the Influence of Road Surfaces on Traffic Noise Using the Continuous-Flow Traffic Time-Integrated Method (CTIM) AASHTO Designation: TP 99-13 (2015) American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Wash
2、ington, D.C. 20001 TS-5a TP 99-1 AASHTO Standard Method of Test for Determining the Influence of Road Surfaces on Traffic Noise Using the Continuous-Flow Traffic Time-Integrated Method (CTIM) AASHTO Designation: TP 99-13 (2015) 1. SCOPE 1.1. The Continuous-Flow Traffic Time-Integrated Method (CTIM)
3、describes the procedures for measuring the influence of road surfaces on highway traffic noise at a specific site. It provides a quantitative measure of the sound pressure level at locations adjacent to a roadway. Measurements capture the sound from existing traffic for all vehicles on all roadway l
4、anes. Measurements also include propagation effects over the roadway pavement and adjacent terrain to the nearby measurement location. 1.2. CTIM is to be applied on roadways where measuring single-vehicle pass-by events would be difficult due to continuously flowing, relatively dense traffic (sound
5、levels from single vehicles cannot be properly captured due to contamination from sound from other vehicles). 1.3. This standard is intended for use by acoustic professionals. Competency with acoustical measurement, modeling, and analysis techniques is assumed. 1.4. This standard may involve hazardo
6、us materials, operations, and equipment. This standard does not purport to address all of the safety concerns associated with its use. It is the responsibility of the user of this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory
7、limitations prior to use. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standards: TP 76, Measurement of Tire/Pavement Noise Using the On-Board Sound Intensity (OBSI) Method TP 98, Determining the Influence of Road Surfaces on Vehicle Noise Using the Statistical Isolated Pass-By (SIP) Method 2.2. ASTM Standar
8、d: F2493, Standard Specification for P225/60R16 97S Radial Standard Reference Test Tire 2.3. FHWA Reports: FHWA-PD-96-008, Development of National Reference Energy Mean Emission Levels for the FHWA Traffic Noise Model (FHWA TNM), Version 1.0 FHWA-PD-96-009, FHWA Traffic Noise Model (FHWA TNM): Users
9、 Guide, TNM Version 2.5 Addendum, April 2004 FHWA-PD-96-010, FHWA Traffic Noise Model (FHWA TNM), Version 1.0: Technical Manual, 2004, update sheets available from FHWA 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of a
10、pplicable law.TS-5a TP 99-2 AASHTO FHWA-PD-96-046, Measurement of Highway-Related Noise, Section 4: Existing-Noise Measurements in the Vicinity of Highways 2.4. IEC Standards: IEC 60942: 2003, ElectroacousticsSound Calibrators IEC 61260: 1995, ElectroacousticsOctave-Band and Fractional-Octave-Band F
11、ilters IEC 61672-1: 2002, ElectroacousticsSound Level MetersPart 1: Specifications 2.5. ANSI Standards: S1.42: 2001 (R2006), American National Standard Design Response of Weighting Networks for Acoustical Measurements S12.8: 1998 (R2008), American National Standard Methods for Determination of Inser
12、tion Loss of Outdoor Noise Barriers 3. TERMINOLOGY 3.1. Definitions: 3.1.1. analysis time blockthe shortest length time block for which all sound level, traffic, and meteorological data are analyzed. The analysis time block length shall range from 5 to 15 min. The length of the analysis time block s
13、hould be long enough to minimize variation in sound levels from one analysis time block to the next, but short enough to facilitate the elimination of periods of time where the measurements were contaminated by nonhighway source noise. (For example, if measuring 15-min analysis time blocks, it would
14、 be undesirable to eliminate the entire 15 min because 5 min of the time period had noise contamination from jets flying overhead; in this case, shorter time blocks would minimize the amount of data lost to contamination.) 3.1.2. control blockthe calculated energy average, Leq, of all modeled analys
15、is time blocks over the first measurement period that meets the data quality criteria specified in this standard. This control block is used for normalization of the remaining analysis data blocks for all data sets. 3.1.3. data setthe acoustical, traffic, and meteorological data collected over a mea
16、surement period during one site visit. 3.1.4. measurement perioda period of time selected to capture enough data to properly represent the site. A minimum of three reporting time blocks or data points are required; additional data are desirable. 3.1.5. On-Board Sound Intensity (OBSI) methoda measure
17、ment procedure to evaluate the tire/pavement noise component resulting from the interaction of an ASTM F2493 Standard Reference Test Tire (SRTT) on a pavement surface. Sound intensity measurements are taken at defined locations near the tire/pavement interface. 3.1.6. powertrain noisethe noise gener
18、ated from the powertrain, including the vehicle engine, exhaust system, air intake, fans, transmission, differential, and axles. 3.1.7. reporting time blocka time block comprised of 15-min Leqsound levels for which sound level, traffic, and meteorological data shall be reported. The reporting time b
19、lock shall be comprised of one or more analysis time blocks. 3.1.8. sampling periodthe period of time over which data are collected during data acquisition. The sampling period must be shorter than or equal to the analysis time block. 2015 by the American Association of State Highway and Transportat
20、ion Officials.All rights reserved. Duplication is a violation of applicable law.TS-5a TP 99-3 AASHTO 3.1.9. Statistical Isolated Pass-By (SIP) methoda test method for measuring the influence of road surfaces on highway traffic noise. The SIP method captures the sound pressure level from isolated veh
21、icles in existing traffic and allows for the comparison of vehicle noise on roadways of varying surfaces and across studies by comparing measured sound levels to a reference noise curve. 3.1.10. tire/pavement noisethe sound generated by the interaction of the tire with the pavement surface as it tra
22、verses the pavement. 3.1.11. traffic noisethe overall noise emitted by multiple vehicles running over the road being evaluated. 3.1.12. vehicle categoriesa vehicle category consists of vehicles that have certain common features easy to identify in the traffic stream, such as the number of axles and
23、the size. The common features are assumed to correspond to similarities in sound emission when driven under the same operating conditions. The following vehicle categories are considered to be sufficient to describe the noise characteristics of road surfaces and are used in this part of the CTIM met
24、hod: Table 1Vehicle Categories Vehicle Category Number of Axles, Number of Tires, Gross Vehicle Weight (examples) Automobiles 2 axles, 4 tires, and generally 9,900 lb (4,500 kg) and 26,400 lb (12,000 kg) Buses 2 or 3 axles (designated for transportation of 9 or more passengers) Motorcycles 2 or 3 ti
25、res (with an open-air driver and/or passenger compartment) Notes: The definitions for these vehicle categories are intended for U.S. applications, including the FHWA Traffic Noise Model (FHWA-PD-96-009, 1.FHWA-PD-96-010) and its vehicle noise emission database (FHWA-PD-96-008). The vehicle category
26、definitions can be found in those references as well as the FHWA highway noise measurement manual (FHWA-PD-96-046). Only vehicles that clearly fall within any of the types described in this Section shall be measured. Where there is any doubt in classifying a vehicle, the 2.measurement for that vehic
27、le shall be discarded from the study. 3.1.13. vehicle noisethe total noise from a vehicle, including a combination of noise generated by the tire/road interaction (tire/pavement noise), air turbulence, and the powertrain. 4. SUMMARY OF TEST METHOD 4.1. A-weighted, time-integrated sound pressure leve
28、ls, traffic volumes, speeds, and vehicle categories, and meteorological data are measured continuously on the side of a roadway for a period of time that captures enough data to properly represent the site. 4.2. The acoustical, traffic, and meteorological data measurements are repeated at the same s
29、ite at a later time to determine either: (1) the difference in sound levels before and after the application of a new surface on the highway; or (2) the difference in sound levels as the pavement on a highway ages. For comparison purposes, traffic and site conditions between data sets should be simi
30、lar; for example, measuring at the same time of day, weekday or weekend, and the same time of year all help to minimize variation. 4.3. To allow for comparisons between data sets, the measured sound levels are normalized for differences due to variations in traffic using the FHWA Traffic Noise Model
31、 (TNM) (FHWA-PD-96-009 and FHWA-PD-96-010), or another model. Traffic data are input into the model to predict the sound levels for the same period of time that the acoustical data were captured and to determine any sound level adjustments necessary to remove traffic variation influences. 2015 by th
32、e American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-5a TP 99-4 AASHTO Note 1This procedure does not currently allow for site-to-site comparison. 5. SIGNIFICANCE AND USE 5.1. This CTIM method provides a measure of t
33、he influence of road surfaces on traffic noise at a specific site adjacent to a roadway and allows for the comparison of different pavement conditions at a specific site, either due to changes over time or through the application of a new pavement surface. 5.2. CTIM measurements capture the sound fr
34、om existing traffic for all vehicles on all roadway lanes and include propagation effects over the roadway pavement and adjacent terrain to the nearby measurement location. Although it may be possible to compare results across studies through the use of noise modeling to reduce site and traffic diff
35、erences, the procedure for such comparisons is not included in this standard at this time. 5.3. The CTIM procedure reports broadband A-weighted, time-integrated sound pressure levels. While it is possible to measure one-third octave band levels in conjunction with the broadband levels, methods to an
36、alyze the one-third octave band data are not included in this procedure. 5.4. CTIM should be applied on roadways with continuously flowing and sufficiently dense traffic that sound levels from single vehicles cannot easily be captured due to sound contamination from other vehicles. In situations whe
37、re lower traffic volumes allow for the measurement of single vehicle pass-by events without contamination from other vehicles, TP 98, Determining the Influence of Road Surfaces on Vehicle Noise Using the Statistical Isolated Pass-By (SIP) Method, or other similar method should be applied. The approp
38、riate measurement technique should be selected based on site and traffic conditions. 5.5. The CTIM test method may be used in conjunction with the on-board sound intensity (OBSI) method described in TP 76 that measures the tire/pavement component of vehicle noise exclusively. 6. APPARATUS 6.1. Sound
39、 Level InstrumentationThe sound level meter (or equivalent measuring system) shall meet the requirements of a Class 1 instrument according to IEC 61672-1. Note 2It is recommended to use a pressure response/random incidence microphone at grazing incidence (i.e., vertical orientation); see Figure 1. F
40、igure 1Illustration of Directions for Microphone Orientation Normal IncidenceGrazing IncidenceMicrophoneAxis 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-5a TP 99-5 AASHTO 6.2. WindscreensA windscr
41、een that does not detectably influence the measured sound levels shall be used. 6.3. Frequency Analysis InstrumentationFrequency analysis of the measured sound using one-third octave-band resolution is recommended, but not mandatory. The frequency range of 50 to 10 000 Hz (center frequencies of one-
42、third octave bands) shall be covered. The one-third octave-band filters shall conform to IEC 61260. 6.4. Calibration InstrumentationThe acoustic calibration device used shall meet the requirements of a Class 1 instrument according to IEC 60942. (Note that some calibrators require correction for envi
43、ronmental conditions. The manufacturers specifications should be consulted.) 6.5. Vehicle Speed Measurement InstrumentationThe average vehicle speed for each lane of travel shall be determined. A list of measuring devices/methods is found in Measurement of Highway-Related Noise (FHWA-PD-96-046) and
44、includes radar gun, stopwatch, light sensors, and pneumatic tubes. Care must be taken to avoid interfering with the sound level measurements, including actions that could influence driver behavior and/or generating any intrusive noise caused by a measurement device. The vehicle speed measuring instr
45、ument(s) shall have an accuracy of 1 mph (1.6 km/h) for the range of speeds of interest. 6.6. Temperature Measurement InstrumentationThe air temperature measuring instrument(s) shall have an accuracy of 2F (1.2C). Meters using an infrared technique shall not be used to measure air temperature. 6.7.
46、Traffic Counting InstrumentationTraffic volumes shall be collected. Traffic-counting instrumentation or methods shall not interfere with noise measurements. 6.8. Wind Measurement InstrumentationThe wind speed measuring instrument(s) shall have an accuracy of 2 mph (0.9 m/s). The wind direction measu
47、ring instrument(s) shall have an accuracy of 10 degrees. 7. SELECTION OF TEST SITES 7.1. The following considerations apply for site selection: 7.1.1. Each road test section shall extend for a distance of at least four times the distance from the center of the near travel lane to the microphone loca
48、tion in both the up- and down-stream directions from the microphone location. For example, for a microphone located at a distance of 50 ft (15.2 m) from the center of the near travel lane, the road test section must extend 200 ft (61 m) in each direction. 7.1.2. The road shall be essentially level a
49、nd straight. Horizontal curves should be avoided when possible. Roadway geometry and approximate grade shall be noted. 7.1.3. A test section shall have the same nominal material and surfacing for its length. The road surface should be homogeneous over the entire test section and the test section should be representative of the road under study. The condition of the road should be documented with pictures of the typical surface included when possible. For example, if the pavement is generally free of distress, the test
