nchrp project 1-44: measuring tire-pavement noise at the...

NCHRP Project 1-44: Measuring Tire-Pavement Noise at the Source

APPENDIX D

Demonstration Testing of OBSI Procedure

D-1

Introduction The intent of this portion of the research was to demonstrate the applicability of the OBSI measurement method for quantifying the effect of different pavement types in relationship to total vehicle noise emissions measured with the CPB and SPB methods. Testing included the simultaneous measurement of OBSI on specific candidate test tires, controlled passbys on test vehicles equipped with those tires (CPB), and statistical passbys of both light and heavy-duty vehicles (SPB) was performed on in-service pavements. Chapter 5 summarizes the measurements completed, the results of the OBSI and passby testing, the relationships between the OBSI and passby data, and the implications of the results to the test procedure. This appendix includes some additional information on the measurement sites, SPB and CPB vs. speed plots, cross-plots of SPB, CPB, and OBSI results, differences in passby levels measured at 25 and 50ft, predicted SPB levels, and spectra for CPB and OBSI levels. Measurement Sites The OBSI and passby testing was conducted at a total of twelve sites in Iowa and California. The five Iowa sites were located along U.S. Highway 30 between mileposts 178 and 198, near Marshalltown. Portions of this section of highway were recently constructed to include many different types of surface texturing and are currently being studied under the FHWA Concrete Pavement Surface Characteristics project by the National Concrete Pavement Technology Center (CP)i. Along this section of highway, four different PCC texture sections were selected as test sites, including a burlap drag surface, a random transverse tined surface, a uniformly tined surface, and a longitudinally tined surface. In addition, a nearby hot mix AC pavement section was selected as a test site. In California, four of the Caltrans test sections on LA 138ii were tested, including DGAC, OGAC, rubberized, and bonded wearing course AC pavements. Two PCC sections, a grooved and a ground pavement, were measured on the Caltrans research sites on the Mojave Bypass (KN 58)iii. In addition, a highly porous rubberized AC pavement was measured along Shasta 299, about 5 miles east of Redding. A summary of the 12 measurement sites is given in Table D-1.

D-2

Table D-1: Summary of Measurement Sites

Site # Location Description

Controlled Test Speeds

1 Iowa US 30 Burlap 50, 55, 60, 65 mph 2 Iowa US 30 R. Trans 50, 55, 60, 65 mph 3 Iowa US 30 U. Trans 55, 60, 65, 70 mph 4 Iowa US 30 DGAC 50, 55, 60 mph 5 Iowa US 30 Long. 55, 60, 65, 70 mph 6 Lancaster, CA LA 138 DGAC 50, 55, 60, 65 mph 7 Lancaster, CA LA 138 OGAC 50, 55, 60, 65 mph 8 Lancaster, CA LA 138 RAC 50, 55, 60, 65 mph 9 Lancaster, CA LA 138 BWC 50, 55, 60, 65 mph 10 Mojave, CA KN 58 Groove 60, 65, 70 mph 11 Mojave, CA KN 58 Ground 60, 65, 70 mph 12 Redding, CA Shasta 299 RAC(O) 55, 60, 65, 70 mph

Measurement site locations are shown in Figures D1 through D-5. A photograph of an example OBSI setup is given in Figure D-6. Photographs of the pavement sections, the passby measurement setups, and the average OBSI ⅓ octave band spectrum at 60 mph are shown in Figures D-6 through D-18 for each surface. Figure D-1: Iowa Test Site Measurement Locations 1, 2, and 5

Site 2 Site 1

Site 5

D-3

Figure D-2: Iowa Test Site Measurement Locations 3 and 4

Figure D-3: California LA 138 Site Measurement Locations

Site 3

Site 4

Site 6 Site 7

Site 8 Site 9

D-4

Figure D-4: California Mojave KN 58 Site Measurement Locations

Figure D-5: California Redding/Shasta 299 Site Measurement Location

Site 10 Site 11

Site 12

D-5

Figure D-6: Example OBSI Measurement Configuration

OBSI Equipment Mounted on SRTT Tire OBSI Equipment Mounted on Dunlap Tire

D-6

Figure D-7: Site 1, US 30 Burlap Drag PCC

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D-7

Figure D-8: Site 2, US 30 Random Transverse Tined PCC

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Figure D-9: Site 3, US 30 Uniform Transverse Tined PCC

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Figure D-10: Site 4, US 30 DGAC

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D-10

Figure D-11: Site 5, US 30 Longitudinally Tined PCC

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D-11

Figure D-12: Site 6, LA 138 DGAC

*Photo from Prior May 2007 Measurements of Test Section

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Site 6, LA 138 DGAC

Pavement Type DGAC Thickness of Overlay 30-mm % Passing No. 4 Sieve 69 Avg. % Air Void Content 5 Construction Date Spring 2002

D-12

Figure D-13: Site 7, LA 138 OGAC

*Photo from Prior Measurement of Test Section

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Site 7, LA 138 OGAC

Pavement Type OGAC Thickness of Overlay 75-mm % Passing No. 4 Sieve 50 Avg. % Air Void Content 9 Construction Date Spring 2002

D-13

Figure D-14: Site 8, LA 138 RAC

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Site 8, LA 138 RAC

Pavement Type RAC-O Thickness of Overlay 30-mm % Passing No. 4 Sieve 50 Avg. % Air Void Content 13 Construction Date Spring 2002

D-14

Figure D-15: Site 9, LA138 Bonded Wearing Course (BWC)

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Site 9, LA 138 BWC

Pavement Type BWC Thickness of Overlay 30-mm % Passing No. 4 Sieve 54 Avg. % Air Void Content 6 Construction Date Spring 2002

D-15

Figure D-16: Site 10, Mojave Grooved PCC

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Site 10, Mojave Grooved PCC

Type Grooved Base Texture Burlap Drag Groove Spacing ¾ in Groove Depth ¼ in Joint Spacing 11 to 14 feet

D-16

Figure D-17: Site 11, Mojave Ground PCC

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Site 11, Mojave Ground PCC

Type Texture Grind Base Texture Burlap Drag Blade Spacing 0.105 in Joint Spacing 11 to 14 feet

D-17

Figure D-18: Site 12, Shasta 299 Redding RAC(O)

*Photo from May 2007 Measurement of Test Section

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Site 12, Shasta 299 Redding RAC

Pavement Type RAC-O Construction Date Spring 2007

Average Sample Length During post-analysis, the 60 mph samples were reanalyzed into shorter sample segments to assess the variation of OBSI level over the standard 440 ft test section. A summary of the range in levels over the 1-second sample lengths is shown in Table D-2. Table D-2: Range in OBSI Using 1-second Avg Times over 4 or 5-second Sample Length

US 30 Burlap

US 30 R. Trans

US 30 U. Trans

US 30 DGAC

US 30 Long.

LA 138 DGAC

LA 138 OGAC

LA 138 RAC

LA 138 BWC

KN 58 Groove

KN 58 Ground

SR 299 RAC(O)

Range 1.0 dB 2.0 dB 0.6 dB 1.6 dB 1.4 dB 0.3 dB 0.4 dB 0.5 dB 0.5 dB 0.6 dB 0.6 dB 3.2 dB StDev 0.4 0.8 0.2 0.6 0.6 0.2 0.2 0.2 0.2 0.3 0.3 1.2

Using 1-second averaging times, the range of levels over 6 of the 12 test sections were within 0.6 dB, with standard deviations of 0.2 to 0.3, indicating that these pavement sections were fairly homogeneous. The SR299 test section showed the largest variation in levels, with a range of 3.2 dB over the test section and a standard deviation of 1.2. This is likely due to the varying aggregate size, which typically dominates the overall A-weighted level of porous pavements. Similar ranges in OBSI levels have been seen in the past on this segment of highwayiv, as well as on other sections of RAC(O) in Californiav. The random transverse PCC section on US 30 also showed considerable variation, likely due to the variability in the depth of the tining, which was observed during the field measurement. Similar variability has been seen in past studiesvi. Three 60 mph passes for the SR299 section using the SRTT tire were reanalyzed in this manner and compared, as shown in Table D-3. Although the locations of the start and finish of the section were not the same for each pass, the variation in the pavement was similar for all three passes, with higher levels at the start of the section and lower levels towards the end. Table D-3: Variation in OBSI Over 5-second Sample Length for Site 12 (SR299), 60 mph

Sample Time Segment 0 to 1 sec 1 to 2 sec 2 to 3 sec 3 to 4 sec 4 to 5 sec Pass 1 101.4 dBA 99.7 dBA 99.6 dBA 98.8 dBA 99.8 dBA Pass 2 101.8 dBA 100.1 dBA 99.4 dBA 98.7 dBA 99.6 dBA Pass 3 101.5 dBA 100.4 dBA 99.5 dBA 98.7 dBA 99.1 dBA

Average 101.6 dBA 100.0 dBA 99.5 dBA 98.7 dBA 99.5 dBA Range 0.4 dB 0.7 dB 0.2 dB 0.2 dB 0.7 dB StDev 0.2 0.4 0.1 0.1 0.3

The random transverse PCC section was also assessed in this manner, shown in Table D-4. Although, the pass-to-pass variation was smaller than the variation between 1-second sample time segments for a single pass, differences of up to 1.3 dB occurred. Again variability in the depth of the tining, which would also vary with slight changes in the wheel path of each pass, is probably the cause.

D-18

Table D-4: OBSI Over 5-second Sample Length for Site 2 (US 30 R. Trans), 60 mph

Sample Time Segment 0 to 1 sec 1 to 2 sec 2 to 3 sec 3 to 4 sec 4 to 5 sec Pass 1 106.0 dBA 106.0 dBA 107.1 dBA 105.8 dBA 105.6 dBA Pass 2 105.6 dBA 106.2 dBA 106.5 dBA 104.5 dBA 105.2 dBA Pass 3 106.3 dBA 106.8 dBA 105.9 dBA 104.8 dBA 105.8 dBA

Average 106.0 dBA 106.3 dBA 106.5 dBA 105.0 dBA 105.6 dBA Range 0.7 dB 0.7 dB 1.2 dB 1.3 dB 0.6 dB StDev 0.3 0.4 0.6 0.7 0.3

Based on this analysis, it is clear that there is variability along some pavement sections that could affect the correlation between at-the-source and passby measurements. However, 4 and 5 second average levels for each site are shown to be as appropriate as any for the OBSI/passby analysis.

D-19

Controlled and Statistical Passby Results As documented in the main portion of this report, statistical vehicle passby measurements were done generally following the procedures provided by FHWA in the “Measurement of Highway-Related Noise” Reportvii and supplemented as needed with the procedures of ISO 11819-1viii. Two microphone positions were used; one at a distance of 25 ft from the centerline of travel (per ISO 11819-1) and one at a distance of 50 ft (per FHWA procedures). Microphones were set at height of 5 ft above the height of the pavement (FHWA). An example passby measurement setup is shown in Fig. 9 of the main report. Passby time histories were captured on a RTA using “fast” response on a ⅓ octave band basis in 1/10th second intervals. The maximum level for each passby was then determined from a plot of overall sound pressure levels calculated for a range from 25 to 20000 Hz versus time. Vehicle speed and type (light vehicle, medium or heavy duty truck, or “other”) were documented for each passby event at each of the test sites documented in the previous Section. Using the ISO 11819-1 criterion, maximum passby levels for acoustically “clean” events were determined and paired with the appropriate speed and vehicle type for the 25 ft and 50 ft microphone positions. Levels for both the SPB and CPB events were then plotted against vehicle speed for both light vehicles and heavy trucks. The data were then fit with a standard logarithmic regression producing an equation and r2 value. The resultant plots are provided in Figs. E-19 through E-30. In each case, the passby levels for a control test vehicle equipped with each of the two tire types, the light vehicle statistical events, and the heavy truck events at measured at 25 and 50ft are presented as available.

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SRTT 50ft

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Figure D-19: SPB and CPB levels versus speed for heavy and light vehicles at 25 and 50 ft for the burlap drag PCC pavement site on US 30 in Iowa

D-20

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Figure D-20: SPB and CPB levels versus speed for heavy and light vehicles at 25 and 50 ft for the random transverse tine PCC pavement site on US 30 in Iowa

D-21

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Hvy Trucks 50ft

Figure D-21: SPB and CPB levels versus speed for heavy and light vehicles at 25 and 50 ft for the uniform transverse tine PCC pavement site on US 30 in Iowa

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Figure D-22: SPB and CPB levels versus speed for heavy and light vehicles at 25 and 50 ft for the hot mix asphalt pavement site on US 30 in Iowa

D-22

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Figure D-23: SPB and CPB levels versus speed for heavy and light vehicles at 25 and 50 ft for the longitudinally tined PCC pavement site on US 30 in Iowa

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Figure D-24: SPB and CPB levels versus speed for heavy and light vehicles at 25 and 50 ft for the dense grade AC pavement site on LA 138 in California

D-23

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Figure D-25: SPB and CPB levels versus speed for heavy and light vehicles at 25 and 50 ft for the open grade AC pavement site on LA 138 in California

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Hvy Trucks 50ft

Figure D-26: SPB and CPB levels versus speed for heavy and light vehicles at 25 and 50 ft for the rubberized AC pavement site on LA 138 in California

D-24

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Figure D-27: SPB and CPB levels versus speed for heavy and light vehicles at 25 and 50 ft for the bonded wearing course AC pavement site on LA 138 in California

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Figure D-28: SPB and CPB levels versus speed for heavy and light vehicles at 25 and 50 ft for the grooved PCC pavement site on Kn 58 in California

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Figure D-29: SPB and CPB levels versus speed for heavy and light vehicles at 25 and 50 ft for the ground PCC pavement site on Kn 58 in California

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Hvy Trucks 50ft

Figure D-30: SPB and CPB levels versus speed for heavy and light vehicles at 25 and 50 ft for the rubberized open graded AC pavement site on Sha 299 in California

D-26

D-27

CPB, OBSI, SPB Cross-Plots In Chapter 5 of the main body of the report, examples of cross-plots of CPB vs. OBSI, SPB vs. OBSI, and SPB vs. CPB were presented for the 25ft measurement distance and the SRTT (Figures 14 through 20). The slopes and r2 values of the linear regressions through the data points along with the offset of a 1-to-1 best fit of the data points and standard and average deviations for both microphone positions and both test tires were presented in Tables 7 through 10 of the report. In this section, the remainder of the cross-plots for the Dunlop tire at 25ft, and the SRTT and Dunlop tires at the 50 ft distance are presented.

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US 30 LTLA138 S1LA138 S2LA138 S4LA138 S5Moj S1Moj S2Redding1-to-1 Fit

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Figure D-31: Controlled vehicle passby levels at 25 ft versus OBSI level for the Dunlop tire at all test sites and speeds – raw data

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LA138 S5Moj S1Moj S2

Redding1-to-1 Fit

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Figure D-32: Controlled vehicle passby levels at 25 ft versus OBSI level for the Dunlop tire at all test sites and speeds – normalized data

D-28

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Figure D-33: Statistical light vehicle passby levels at 25 ft versus OBSI level for the Dunlop tire at all test sites and speeds – raw data

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Figure D-34: Statistical light vehicle passby levels at 25 ft versus OBSI level for the Dunlop tire at all test sites and speeds – normalized data

D-29

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Figure D-35: Statistical light vehicle passby levels at 25 ft versus controlled vehicle passby level for the Dunlop tire at all test sites and speeds

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Figure D-36: Statistical heavy truck passby levels at 25 ft versus OBSI level for the Dunlop tire at all test sites and speeds – raw data

D-30

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US 30 BDUS 30 TTUS 30 UTUS 30 ACUS 30 LTLA138 S1LA138 S2LA138 S4LA138 S5Moj S1Moj S2Redding

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Figure D-37: Statistical heavy truck passby levels at 25 ft versus OBSI level for the Dunlop tire at all test sites and speeds – normalized data

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Figure D-38: Controlled vehicle passby levels at 50 ft versus OBSI level for the SRTT at all test sites and speeds – raw data

D-31

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Figure D-39: Controlled vehicle passby levels at 50 ft versus OBSI level for the SRTT at all test sites and speeds – normalized data

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Figure D-40: Statistical light vehicle passby levels at 50 ft versus OBSI level for the SRTT at all test sites and speeds – raw data

D-32

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Figure D-41: Statistical light vehicle passby levels at 50 ft versus OBSI level for the SRTT at all test sites and speeds – normalized data

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D-33

Figure D-42: Statistical light vehicle passby levels at 50 ft versus controlled vehicle passby level for the SRTT at all test sites and speeds

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Figure D-43: Statistical heavy truck passby levels at 50 ft versus OBSI level for the SRTT at all test sites and speeds – raw data

D-34

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evel

, dB

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11 113 115


Linear

Figure D-44: Statistical heavy truck passby levels at 50 the SRTT at all test sites and speeds – normalized data

ft versus OBSI level for

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Figure D-45: Controlled vehicle passby levels at 50 ft versus OBSI level for the Dunlop tire at all test sites and speeds – raw data

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AUS 30 BDUS 30 TTUS 30 UT

US 30 LTLA138 S1LA138 S2LA138 S4

LA138 S5Moj S1Moj S2

Redding1-to-1 Fit

Linear

Figure D-46: Controlled vehicle passby levels at 50 ft versus OBSI level for the Dunlop tire at all test sites and speeds – normalized data

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D-35

Figure D-47: Statistical light vehicle passby levels at 50 ft versus OBSI level for the Dunlop tire at all test sites and speeds – raw data

D-36

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A 76

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Figure D-48: Statistical light vehicle passby levels at 50 ft versus OBSI level for the Dunlop tire at all test sites and speeds – normalized data

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Lt V

ehic

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tatis

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Figure D-49: Statistical light vehicle passby levels at 50 ft versus controlled vehicle passby level for the Dunlop tire at all test sites and speeds

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AUS 30 BDUS 30 TTUS 30 UTUS 30 ACUS 30 LTLA138 S1LA138 S2LA138 S4LA138 S5Moj S1Moj S2Redding

Linear

Figure D-50: Statistical heavy truck passby levels at 50 ft versus OBSI level for the Dunlop tire at all test sites and speeds – raw data

D-37

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Figure D-51: Statistical heavy truck passby levels at 50 ft versus OBSI level for the Dunlop tire at all test sites and speeds – normalized data

D-38

Comparison of 25 and 50ft Passby Levels As part of the data analysis, the difference in overall A-weighted passby level between the 25 and 50ft positions was calculated for each passby event at each site for which data at both locations were available. For these differences, the average for each site was determined along with the range and standard deviation. In the analysis, the difference in level for light vehicles and heavy trucks was processed separately. The average differences for the sites and vehicle types are provided in Figure D-52.

From this figure, the total range between sites is 3.6 for light vehicles and 2.4 for heavy trucks. This is indicative of significant site-to-site variation, affecting the sound propagation from the 25 to 50ft microphone locations. In most cases, the difference in the averages between light vehicles and heavy trucks is about ½ dB or less. In some cases, however, the difference approaches 1 dB. The average for all sites is 6.6 dB for light vehicles and 6.4 dB for heavy trucks. Also, generally, the site-to-site variation tracked similarly for both vehicle types. A table of these averages, the standard deviation and range at each site are presented in Table D-5. For both vehicles types, the standard deviation of the difference is less than 1 dB with the trucks typically having slightly larger deviations.

0

1

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IA 30

S1

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S5

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S1

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Leve

l Diff

eren

ce, d

B

S2

Reddin

g

Light VehiclesHeavy Trucks

Figure D-52: Averages for the difference between 25 and 50ft passby levels for light vehicles and heavy trucks

Table D-5: Average, standard deviation, and range for the difference between 25 and 50ft passby levels for light vehicles and heavy trucks

Light Vehicles Heavy Trucks Site Avg. Std. Dev. Range Avg. Std. Dev. Range US 30 Burlap 6.0 0.56 2.7 6.2 0.75 2.4 US 30 R. Trans 6.1 0.68 4.1 5.8 0.58 2.2 US 30 U. Trans 7.2 0.69 4.5 6.9 0.66 4 US 30 Long. 7.3 0.65 3.7 6.3 0.83 4.3 LA 138 DGAC 8.5 0.68 3.6 7.7 0.71 3.9 LA 138 OGAC 7.0 0.58 3.4 6.7 0.77 4.4 LA 138 RAC 8.1 0.61 3.2 7.0 0.90 3.6 LA 138 BWC 7.2 0.62 3.8 6.9 0.60 2.8 Mojave Groove 4.9 0.59 4.1 5.8 0.79 3.8 Mojave Ground 5.1 0.62 3.8 5.6 0.77 4 Redding RAC(O) 5.6 0.56 2.8 5.3 0.64 2.5

D-39

Prediction of SPB Using OBSI Levels In Chapter 5 of the main report, plots comparing predicted SPB levels for both light vehicles and heavy trucks at 60 mph were presented (Figures 21 through 24). These were calculated by subtracting the offsets from Tables 8 and 10 from the OBSI data for each tire. This yields a predicted SPB level based on either the SRTT or Dunlop tire at whatever OBSI test speed is selected. Depending on which offset is selected, the SPB levels for light vehicles or trucks at 25 or 50 ft can be predicted. Further, the predicted SPB levels can be compared to both the raw and normalized SPB levels. In Chapter 5 the results for 60 mph, 25 and 50ft, and light vehicles and heavy trucks were shown as examples. In this subsection, plots are provided for light vehicles and heavy trucks at speeds of 50, 55, and 65 mph for the 25ft microphone distance (Figures D-53 through D-58).

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SPB - Predicted Based on SRTT SPB - Predicted Based on Dunlop SPB - Measured Raw DataSPB - Measured Normalized Data

Figure D-53: Predicted SPB based on SRTT and Dunlop tires OBSI and measured light vehicle SPB levels at 50 mph and 25 ft - raw and normalized

D-40

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ASPB - Predicted Based on SRTT SPB - Predicted Based on Dunlop SPB - Measured Raw DataSPB - Measured Normalized Data


D-41

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ASPB - Predicted Based on SRTT SPB - Predicted Based on Dunlop SPB - Measured Raw DataSPB - Measured Normalized Data

Figure D-56: Predicted SPB based on SRTT and Dunlop tires OBSI and measured Heavy truck SPB levels at 50 mph and 25 ft - raw and normalized

D-42

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Figure D-57: Predicted SPB based on SRTT and Dunlop tires OBSI and measured Heavy truck SPB levels at 55 mph and 25 ft - raw and normalize

D-43

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Figure D-58: Predicted SPB based on SRTT and Dunlop tires OBSI and measured Heavy truck SPB levels at 65 mph and 25 ft - raw and normalize

⅓ Octave Band Spectrum Comparison for OBSI and CPB results

ent phase of this ade within the

the CPB data at 25ft and of ph (Figs. D-59 through D-62). As

ilar for the nt near Redding,

nt S4 at NCAT. Also, this ared to the other

ith the SRTT, a

frequency of this peak the

e for ximum overall crophone array

the frequency is elevated at

” is not shifted and

Given the large amount of data collected in the passby measuremresearch, only limited comparisons of ⅓ octave band spectra could be mscope of this project. In this section, spectral comparisons ofthe OBSI levels are presented for each test site at 60 mindicated in these plots, the overall trends between the tires and sites are simCPB and OBSI data. In all of the data, the porous Shasta 299 pavemeCA displays a “dip” in level between 1000 and 2500 Hz. This was expected based on the results of the test track measurements completed on pavemepavement tends to produce higher low frequency noise levels as compsurfaces, with the exception of the random transverse tined PCC. W“peak” in the uniform transversely tined PCC occurs above 1000 Hz, corresponding to the passage frequency of the tines. It is interesting to note that the shifts between the OBSI and passby data. The reason for this can be visualized from“waterfall” plot of Figure D-63, which shows sound level versus frequency and timthe CPB measurement. For the CPB measurement, the time of the malevel occurs prior to the vehicle reaching the closest approach to the micenterline. As a result of Doppler shifting of the tonal sound, this point (1600 Hz band) and then shifts down 1 third octave after the vehicle passes. With OBSI, which measures the constant frequency tone, the “peakoccurs in the 1250 Hz ⅓ octave band.

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LA 138 Site 1

LA 138 Site 2

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Mojave 1

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Redding

Figure D-59: ⅓ Octave band spectra of controlled passby sound pressure levels at 25ft for SRTT at 60 mph

D-44

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Redding

Figure D-60: ⅓ Octave band spectra of controlled passby sound pressure levels at 25ft for Dunlop tire at 60 mph

D-45

Figure D-61: ⅓ Octave band spectra of on-board sound intensity levels at for the SRTT at 60 mph

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Redding

D-46

Figure D-62: ⅓ Octave band spectra of on-board sound intensity levels at for the Dunlop tire at 60 mph

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00.4

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Time of Max Passby Level

Figure D-63: Sound level vs. frequency and time for SRTT passby on uniform transversely tined PCC

D-47

UReferences: i Wiegand, P, Cable, J., Reinert, S., and Tabbert, T., “Field Experiments of Current Concrete Pavement Surface Characteristics Practices: Iowa Data Collection and Analysis”, Report No. FHWA DTFH61-01-X-00042 (Project 15, Part 2) IHRB Project TR-537, Center for Transportation Research and Education, Iowa State University, Ames, IA, December 2005. ii Rochat, J., Reed, D., and Fleming, G., “Status Report: Caltrans Rte 138 Tire/Pavement Noise Study”, Technical Memorandum, Volpe Center Acoustics Facility, U.S. Department of Transportation, June 2004. iii Donavan, P., “Influence of PCC Surface Texture and Joint Slap on Tire/Pavement Noise Generation”, Proceedings of NoiseCon 2004, Baltimore, MD, July 2004. iv Lodico, D. “District 02 Shasta 299 MP 24.2/30.8, OBSI Measurements”, Illingworth & Rodkin, Inc. Technical Memo, Caltrans District 3, June 11, 2007. v Donavan, P., “Illingworth & Rodkin Updates”, Proceedings of the FHWA Tire/Pavement Noise Strategic Planning Workshop, Purdue University, Indianapolis, IN, April 2006 vi Thornton, W, Hanson, D, and Scofield, L, “Acoustical Variability of Existing Pavements”, NOISE-CON 2004, July 12-14, 2004. vii Lee, C. and Fleming, G., “Measurement of Highway-Related Noise”, U.S. Department of Transportation, Report No. DOT-VNTSC-FHWA-96-5, 1996. viii International Organization of Standardization. “ISO/CD 11819-1. Acoustics – Measurement of the influence of road surfaces on traffic noise – Part 1: Statistical Pass-by Method”, ISO, Geneva, Switzerland, 2000.

nchrp project 1-44: measuring tire-pavement noise at the...

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