1. The Effects of Pavement Properties on Road Tire Noise Wing-tat HUNG, Wing-gun WONG Chung-fai NG, Chi-ho YIM The Hong Kong Polytechnic University

2. Introduction Factors affecting Pavement Noise: Method of measurement Mobilized measurement methods: trailer and on- board microphone Stationary measurement methods: coast-by, controlled pass-by and statistical pass-by  Pavement type and thickness  Surface texture and aggregate size  Traffic speed  Frequency range

3. Trailer and Pass-By Method

4. On-board Microphone Method

5. On-board Measurement microphone locations

6. On-board Measurement Method with skirting

7. Our Modified Close Proximity Method

8. Detailed Equipment Set-up

9. Site No.LocationType of PavementAge of PavementSurface Thickness 1aIsland Eastern Corridor Between A Kung Ngam Road and Heng Fa Chuen (From A Kung Ngam to Lei Yue Mun Banack) Porous friction course (PFC)June 199830 mm thick friction course on 20 mm thick cushion course 1bIsland Eastern Corridor Between A Kung Ngam Road and Heng Fa Chuen (From Lei Yue Mun Banack to Heng Fa Chuen) Polymer modified friction course (PMFC) April 2001i.30 mm thick friction course on 20 mm thick cushion course ii.30 mm thick friction course on 40 mm thick wearing course 2Island Eastern Corridor From Oil Street to Tin Chui Street Polymer modified friction course (PMFC) April 199830 mm thick friction course on 20 mm thick cushion course 3Island Eastern Corridor From Sai Wan Ho Slip Road to Tai Hong Street Polymer modified friction course (PMFC) November 2000i.30 mm thick friction course on 40 mm thick wearing course ii.45 mm thick wearing course only 4Kwun Tong Bypass From Wai Yip Street to Shing Yip Street Bridge deck overlaid with asphalt (BDOA) 2001N.A. 5Kwun Tong Road From Choi Wan Road to Ping Shek Estate Concrete overlaid with asphalt (PCC) 1999N.A. 6Kwun Tong Road From Yan Wing Building to Telford Garden Block U1 Asphalt (Bituminous pavement, ABP) 2001N.A. 7Lai Chi Kok Bay Bridge From Ching Lai Court to Mei Fu Sun Chuen Bridge deck overlaid with asphalt (BDOA) 2001N.A. 8Lung Cheung Road (Diamond Hill) From Hammer Hill Road to Po Kong Village Road Concrete overlaid with asphalt (PCC) 1999N.A. 9Lung Cheung Road (Wong Tai Sin) From Po Kong Village Road to Fung Mo Street Stone Mastic Asphalt (SMA)1999N.A. 10Princess Margaret Road From Chatham Road South to Wylie Road Concrete overlaid with asphalt (PCC) 1999N.A. 11Tolo Highway From Tai Po Kiu to Ma Liu Shui Polymer modified friction course (PMFC) March 200130 mm thick friction course on 40 mm thick wearing course 12Tuen Mun Road From Siu Lam to Tai Lam Porous friction course (PFC)1999N.A. 13Tuen Mun Road From Ting Kau to Chai Wan Kwok Porous friction course (PFC)1999N.A. 14Western Kowloon Corridor From Tonkin Street to Cheung Sha Wan Bridge deck overlaid with asphalt (BDOA) 2001N.A. 15Western Kowloon Expressway From Tonkin Street to Olympic Center Bridge deck overlaid with asphalt (BDOA) 1997N.A. Selected Pavements for Noise Measurements

10. Sound Level Calibration

11. Site No.Type of PavementYear of Construction L eq (dBA) 50 km/h70 km/h100 km/h 1aPorous friction courseJune 199899.1100.6--- 1b (i)Polymer modified friction courseApril 200197.896.1--- 1b (ii)Polymer modified friction courseApril 200192.799.5--- 2Polymer modified friction courseApril 1998101.1104.7--- 3 (i)Polymer modified friction courseNovember 200097.5--- 3 (ii)Polymer modified friction courseNovember 200096.9--- 4Bridge deck overlaid with asphalt200198.197.8--- 5Concrete overlaid with asphalt (PCC)1999102.1108.2--- 6Asphalt (Bituminous pavement)200196.1102.7--- 7Bridge deck overlaid with asphalt200194.9100.5--- 8Concrete overlaid with asphalt (PCC)1999103.6--- 9Stone Mastic Asphalt (SMA)199998.3100.9--- 10Concrete overlaid with asphalt (PCC)1999100.5106.1--- 11Polymer modified friction courseMarch 200196.797.8104.4 12Porous friction course199999.2102.8--- 13Porous friction course199998.8101.7--- 14Bridge deck overlaid with asphalt200196.3102.0--- 15Bridge deck overlaid with asphalt199798.0101.3105.0 The Pavement Tire Noise Measured Levels

12. RankSite No. Type of PavementYear of Construction L eq (dBA)Difference Relative to Reference (dBA) 11b (ii)Polymer modified friction courseApril 200192.7-6.3 27Bridge deck overlaid with asphalt200194.9-4.1 36Asphalt (Bituminous pavement)200196.1-2.9 414Bridge deck overlaid with asphalt200196.3-2.7 511Polymer modified friction courseMarch 200196.7-2.3 63 (ii)Polymer modified friction courseNovember 200096.9-2.1 73 (i)Polymer modified friction courseNovember 200097.5-1.5 81b (i)Polymer modified friction courseApril 200197.8-1.2 915Bridge deck overlaid with asphalt199798.0 104Bridge deck overlaid with asphalt200198.1-0.9 119Stone Mastic Asphalt (SMA)199998.3-0.7 1213Porous friction course199998.8-0.2 131aPorous friction courseJune 199899.10.1 1412Porous friction course199999.20.2 1510Concrete overlaid with asphalt (PCC)1999100.51.5 162Polymer modified friction courseApril 1998101.12.1 175Concrete overlaid with asphalt (PCC)1999102.13.1 188Concrete overlaid with asphalt (PCC)1999103.64.6 Reference pavement (Average of all porous friction course pavements 99.0 Ranking of pavement surfaces based on measured Leq at 50kph

13. RankSite No.Type of PavementYear of Construction L eq (dBA)Difference Relative to Reference (dBA) 11b (i)Polymer modified friction courseApril 200196.1-5.6 211Polymer modified friction courseMarch 200197.8-3.9 34Bridge deck overlaid with asphalt200197.8-3.9 41b (ii)Polymer modified friction courseApril 200199.5-2.2 57Bridge deck overlaid with asphalt2001100.5-1.2 61aPorous friction courseJune 1998100.6-1.1 79Stone Mastic Asphalt (SMA)1999100.9-0.8 815Bridge deck overlaid with asphalt1997101.3-0.4 913Porous friction course1999101.70.0 1014Bridge deck overlaid with asphalt2001102.00.3 116Asphalt (Bituminous pavement)2001102.71.0 12 Porous friction course1999102.81.1 132Polymer modified friction courseApril 1998104.73.0 1410Concrete overlaid with asphalt (PCC)1999106.14.4 155Concrete overlaid with asphalt (PCC)1999108.26.5 Reference pavement (Average of all porous friction course pavements) 101.7 Ranking of pavement surfaces based on measured Leq at 70kph

14. Comparison of sound spectrums for pavements at 50 kph

15. Comparison of sound spectrums for pavements at 70 kph

16. Comparison of sound spectrums for Friction Courses at 70 kph

17. Site No. Age of Pavement Surface Thickness Equivalent Noise Level L eq (dBA) Difference from Average (dBA) 1biApr 2001 30 mm thick friction course on 20 mm thick cushion course 96.1-3.4 1biiApr 2001 30 mm thick friction course on 40 mm thick wearing course 99.50.0 2Apr 1998 30 mm thick friction course on 20 mm thick cushion course 104.75.2 11Mar 2001 30 mm thick friction course on 40 mm thick wearing course 97.8-1.7 Average99.5 Comparison of Leq with different surface thickness at 70kph

18. RankType of PavementYear of ConstructionL eq (dBA) 1Polymer modified friction course200195.7 2Asphalt (Bituminous pavement)200196.1 3Bridge deck overlaid with asphalt200196.4 4Polymer modified friction course200096.9 5Bridge deck overlaid with asphalt199798.0 6Stone Mastic Asphalt (SMA)199998.3 7Porous friction course199999.0 8Porous friction course199899.1 9Polymer modified friction course1998101.1 10Concrete overlaid with asphalt (PCC)1999102.1 Conclusions At 50 kph

19. RankType of PavementYear of ConstructionL eq (dBA) 1Polymer modified friction course200197.8 2Bridge deck overlaid with asphalt2001100.1 3Porous friction course1998100.6 4Stone Mastic Asphalt (SMA)1999100.9 5Bridge deck overlaid with asphalt1997101.3 6Porous friction course1999102.3 7Asphalt (Bituminous pavement)2001102.7 8Polymer modified friction course1998104.7 9Concrete overlaid with asphalt (PCC)1999107.2 Conclusions At 70 kph

20. Major Findings: 1.Pavement surface type has signifiant impacts on pavement tire noises 2.The equivalent noise levels Leq for all test pavements increased with vehicle speed 3.Sound levels for two-year-old PMFC pavements did not increase significantly while there were increases in sound level of 2.1 dBA and 3.0 dBA for the five-year- old pavement at speed of 50 km/h and 70 km/h respectively

21. Major Findings: 4.The PMFC pavements provide the most significant reduction in equivalent noise levels. 5.The highest equivalent noise level Leq was recorded at the PCC pavements. 6.A 20 mm thick PMFC pavement provides a reduction in sound levels by as much as 3.4 dBA in Leq. END. Thank you