Click for next page ( 21


The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 20
20 will be repeated as appropriate. Prior to leaving the site, the Texture, Friction, and data will be backed up to a CD. If CT Meter equipment Noise Test Results problems are encountered and cannot be resolved, the sand patch test method (ASTM E 965) will be used. This section presents the results of the texture, friction, DF Tester Friction/Micro-texture Measurements--Micro- and noise tests in terms of summaries of the key outputs texture properties of the pavement surfaces will be mea- from these tests as well as other relevant indexes. These sured in accordance with ASTM E 1911. Data will be indexes and the equations for their computations are as collected at the same locations as the CT Meter macro- follows: texture measurements. All data will be checked for rea- sonableness and precision, and tests will be repeated as CT Meter MTD developed using CT Meter MPD and the appropriate. All data will be backed up prior to leaving following NASA/Wallops equation (Henry, 2000): the site. MTD = 0.952 MPD + 0.0036 Formal Testing (US Customary units ) Eq. 3-2a Prior to formal testing of the selected test sections, exten- MTD = 0.952 MPD + 0.091 ( SI units ) Eq. 3-2b sive training was obtained on the different testing equipment. In addition, various calibrations and accuracy checks of the Honda CR-V SI system were performed using a certified SI Texture Orientation (TO) determined based on the ratio system (installed on a Subaru Outback) for comparison. As of MPD to RMS, as measured using the CT Meter. In gen- part of this testing, a series of repeat runs were made by both eral, ratios greater than 1.05 to 1.10 are categorized as pos- systems on each of two asphalt pavement sections and two lon- itive TO. They are representative of an aggressive, protrud- gitudinally tined concrete sections. Results showed negligible ing surface, such as a chip seal surface. Ratios less than 0.90 differences in measurements of pink noise and a slightly lower to 0.95 are categorized as negative TO. They are represen- (<1 dB(A) difference) overall average SI measurement taken by tative of a flat, pocketed surface, such as HMA or grooved the certified system. This difference was partly attributed to PCC. Ratios between these two sets of values are consid- differences in the lateral positioning of the two test vehicles ered to have neutral TO. during testing and to differences in the vehicle suspension and wheel camber characteristics. Texture Ratio ( TR ) = MPD RMS Eq. 3-3 Upon coordination of traffic control with the appropriate personnel in each SHA, formal testing commenced. Measure- ments were conducted during the June 6 to November 5, International Friction Index (IFI) Friction Number F(60), 2005 time period. Table 3-3 lists the specific dates of testing as given in ASTM E 1960: for each test section. Figures 3-3 and 3-4 illustrate the specific locations for texture, friction, and noise measurements on the F ( 60 ) = A + B FR ( S ) e([S-60] SP ) test sections. + C TX ( SI units ) Eq. 3-4 Agency-Supplied Friction Data SP = a + b TX ( SI units ) Eq. 3-5 To supplement the DF Tester friction/micro-texture data, the participating state agencies conducted locked-wheel fric- where tion testing (ASTM E 274) using both a smooth (ASTM E 524) FR(S) = Friction number measured by friction device at and ribbed tire (ASTM E 501) on each test section and pro- speed S. vided the resulting data. Table 3-4 lists the high-speed friction S = Friction test speed, km/hr. data provided by each state. SP = Speed number. As indicated, data were not provided by some states. The pro- TX = Macro-texture measurement. vided data were in most cases for both smooth and ribbed tires A, B, C = Friction device calibration constants. in at least one of the wheelpaths. In some cases, data for a a, b = Macro-texture method calibration constants. locked-wheel tester or one of the specified types of tires were not provided because of agency practices not to perform these tests. Using the A, B, and C calibration constants given in ASTM All locked-wheel test data were collected at 40 mi/hr (64 km/hr). E 1960 for the DF Tester and the locked-wheel friction tester

OCR for page 20
21 Table 3-3. Dates of friction, texture, and noise measurements. Texture Noise Noise Noise Texture Friction State Highway Location Section ID (high-speed) (near field) (interior) (far field) (CTM) (DFT) 1001, 1002, 11/14/05 11/14/05 AZ SR 202 Phoenix 11/16/05 11/16/05 11/16/05 -- 1003, 1004 11/15/05 11/15/05 1002, 1003, 1004, 1045, 11/9/05 11/9/05 CA SR 58 Mojave 11/11/05 11/11/05 11/11/05 11/9/05* 1005, 1007, 11/10/05 11/10/05 1075 1007, 1008, CO I-70 Agate/Deer Trail 10/21/05 10/21/05 10/21/05 -- 10/22/05 10/22/05 1009 1001, 1002, 10/26/05 10/26/05 10/26/05 10/23/05 10/23/05 CO US 287 Berthoud 1003, 1004, 10/26/05* 10/27/05 10/27/05 10/27/05 10/25/05 10/25/05 1005, 1006 IL I-55/74 Bloomington 1001 8/30/05 8/30/05 8/30/05 8/30/05 -- -- IL I-57 Champaign 4001 8/4/05 8/4/05 8/4/05 8/4/05 8/24/05 8/24/05 IL I-70 Marshall 5001 8/25/05 8/25/05 8/25/05 -- 8/26/05 8/26/05 Champaign/ IL I-74 8001 8/4/05 8/4/05 8/4/05 -- 8/5/05 8/5/05 Mahomet 1002, 1003, Des Moines/ IA US 163 1003, 1061, 8/17/05 8/17/05 8/17/05 -- -- -- Prairie City 1007 6/6/06 6/6/06 IA US 34 Mt. Pleasant 2001, 2002 8/15/05 8/15/05 8/15/05 6/7/06* 6/7/06 6/7/06 IA US 218 Washington 8001, 8002 8/16/05 8/16/05 8/16/05 -- -- -- IA US 30 Ames/Nevada 9002 8/17/05 8/17/05 8/17/05 -- -- -- 1002, 1004, 1005, 1006, KS US 69 Louisburg 9/25/05 9/25/05 9/25/05 10/18/05* 9/25/05 9/25/05 1007, 1008, 1010 KS US 54 Batesville 2001 10/19/05 10/19/05 10/19/05 -- -- -- Salina/ KS I-70 4001 9/27/05 9/27/05 9/27/05 9/27/05 9/27/05 9/27/05 Juniata MI I-75 Detroit 1001 10/12/05 10/12/05 10/12/05 -- -- -- Eden Prairie/ MN US 169 1001 9/10/05 9/10/05 9/10/05 -- 9/10/05 9/10/05 Shakopee Brooklyn Park/ MN I-94/694 2003, 2004 9/10/05 9/10/05 9/10/05 -- 9/10/05 9/10/05 Brooklyn Center Fridley/ MN I-694 5001 9/9/05 9/9/05 9/9/05 -- -- -- New Brighton Brooklyn Park/ MN US 169 7001, 8001 9/9/05 9/9/05 9/9/05 -- 9/16/05 9/16/05 Champlin MO US 36 Hannibal 1001 8/8/05 8/8/05 8/8/05 8/8/05 8/8/05 8/8/05 Hillsdale/ NC I-40 1001 7/16/05 7/16/05 7/16/05 -- 7/16/05 7/16/05 Clemmons ND I-94 Glen Ullin 2001, 2002 9/13/05 9/13/05 9/13/05 -- 9/13/05 9/13/05 ND I-94 Valley City 6001 9/11/05 9/11/05 9/11/05 -- 9/11/05 9/11/05 Dallas/ TX I-20 1001 11/18/05 11/18/05 11/18/05 11/19/05 11/19/05 11/19/05 Duncanville WI US 151 Mineral Point 5001 9/6/05 9/6/05 9/6/05 9/6/05 9/6/05 9/6/05 * Control pass-by noise measurement only.

OCR for page 20
22 Inside Lane Outside Lane 1,056 ft typ (end of segment) Pass-by Noise Tests (3 runs per position) Pass-By Noise Equip Setup 25 ft 508 ft SI and Interior Noise and High-Speed Texture Tests (3 runs per position) 18-30 in. 66-78 in. 0 ft (start of segment) Lane Right center WP Figure 3-3. Location of standard noise and high-speed texture testing measurements.

OCR for page 20
23 Inside Lane Outside Lane 1,056 ft typ (end of segment) 860 ft 858, 860, 862 684 ft 682, 684, 686 508 ft 506, 508, 510 332 ft 330, 332, 334 156 ft 154, 156, 158 18-30 in. 66-78 in. 0 ft (start of segment) Lane Right center WP Figure 3-4. Location of standard DF Tester and CT Meter test measurements.

OCR for page 20
24 Table 3-4. Summary of high-speed friction tests performed by participating agencies. Date of State Highway Location Section ID Friction Tester Description Testing Dynatest/KJ Law Fixed-Slip Runway Friction Tester 1001, 1002, 1003, AZ SR 202 Phoenix 5/17/06 (RFT)--foot-by-foot continuous measurement lane center at 1004 60 mi/hr. IL I-55/74 Bloomington 1001 9/21/06 IL I-57 Champaign 4001 9/18/06 Locked-Wheel Friction Tester (ASTM E 274) with both smooth (ASTM E 524) and ribbed (ASTM E 501) tires-- IL I-70 Marshall 5001 9/19/06 Three tests per test section in left wheelpath at 40 mi/hr. Champaign/ IL I-74 8001 9/18/06 Mahomet Des Moines/ 1002, 1003, 1003, IA US 163 9/19/05 Prairie City 1061, 1007 Locked-Wheel Friction Tester (ASTM E 274) with both IA US 34 Mt. Pleasant 2001, 2002 9/12/05 smooth (ASTM E 524) and ribbed (ASTM E 501) tires--Two IA US 218 Washington 8001, 8002 9/12/05 tests per test section in left wheelpath at 40 mi/hr. IA US 30 Ames/Nevada 9002 9/15/05 1002, 1004, 1005, Locked-Wheel Friction Tester (ASTM E 274) with ribbed KS US 69 Louisburg 1006, 1007, 1008, 11/21/05 tire (ASTM E 501)--Three tests per test section in left 1010 wheelpath at 40 mi/hr. KS US 54 Batesville 2001 12/23/05 Locked-Wheel Friction Tester (ASTM E 274) with both Salina/ smooth (ASTM E 524) and ribbed (ASTM E 501) tires--Five KS I-70 4001 12/14/05 tests per test section in left wheelpath at 40 mi/hr. Juniata Locked-Wheel Friction Tester (ASTM E 274) with smooth MI I-75 Detroit 1001 10/25/05 tire (ASTM E 524)--Four tests per test section in right wheelpath at 40 mi/hr. Locked-Wheel Friction Tester (ASTM E 274) with ribbed Hillsdale/ NC I-40 1001 1/10/06 tire (ASTM E 501)--Three tests per test section at lane Clemmons center at 40 mi/hr. Locked-Wheel Friction Tester (ASTM E 274) with both Dallas/ smooth (ASTM E 524) and ribbed (ASTM E 501) tires-- TX I-20 1001 8/4/06 Duncanville Four tests per test section at lane center and in both wheelpaths at 40 mi/hr. Locked-Wheel Friction Tester (ASTM E 274) with both smooth (ASTM E 524) and ribbed (ASTM E 501) tires--Two WI US 151 Mineral Point 5001 6/29/06 tests per test section at lane center and in left wheelpath at 40 mi/hr. 1 mi/hr = 1.61 km/hr Note: No data were provided for sections in California, Colorado, Minnesota, Missouri, and North Dakota. with ribbed and smooth tires, and the a and b coefficients SP = 14.2 + 89.7 MPD ( SI units ) Eq. 3-9 given in ASTM E 1960 for MPD, the following equations were used to compute IFI F(60) values: Using FN40S (i.e., FN(65)S) from locked-wheel tester with smooth tire [ASTM E 274 and E 524]) and high-speed pro- Using DFT(20) from DF Tester and high-speed profiler filer MPD: MPD: F ( 60 ) = 0.045 + 0.925 FN ( 65 ) S e([65-60] S P ) F ( 60 ) = 0.081 + 0.732 DFT ( 20 ) e([20-60] SP ) + 0 MPD ( SI units ) Eq. 3-10 + 0 MPD ( SI units ) Eq. 3-6 SP = 14.2 + 89.7 MPD ( SI units ) Eq. 3-11 SP = 14.2 + 89.7 MPD ( in mm ) Eq. 3-7 Table 3-5 lists the mean texture values based on measure- Using FN40R (i.e., FN(65)R) from locked-wheel tester ments from the right wheelpath and the lane center, the mean with ribbed tire (ASTM E 274 and E 501) and high-speed micro-texture and friction values, and the mean noise levels, profiler MPD: as measured at the pavementtire interface, in the vehicle interior, and at the side of the road for each test section. F ( 60 ) = -0.023 + 0.607 FN ( 65 ) R e([65-60] SP ) (Detailed results of the texture, friction, and noise testing are + 0.098 MPD ( SI units ) Eq. 3-8 presented in Appendix D which is available online.)

OCR for page 20
Table 3-5. Texture, friction, and noise data. SECT CONST HS PROFILER1 CT METER1 DF TESTER1 LOCKED-WHEEL1 SI INT CPB STATE ID HWY YEAR TEXTURE DESCRIPTION MPD, EMTD, MPD, MTD, NOISE, NOISE, NOISE, 2 1 1 mm mm mm mm TR DFT(20) F(60) FN40S F(60) DB(A) DB(A) DB(A) AZ 04-1001 SR 202L 2003 Long DG (no jacks), 0.235-in. spacing (0.11-in. spacers) 0.64 0.72 0.99 1.06 2.30 80.5 41.73 NA NA 104.5 70.4 NA 04-1002 SR 202L 2003 Long DG (jacks), 0.235-in. spacing (0.11-in. spacers) 0.64 0.71 1.01 1.09 2.34 77.0 40. 01 NA NA 105.7 71.8 NA 04-1003 SR 202L 2003 Long DG (no jacks), 0.245-in. spacing (0.12-in. spacers) 0.89 0.92 1.58 1.65 2.45 81. 0 46.89 NA NA 106.35 73.5 NA 04-1004 SR 202L 2003 Long DG (jacks), 0.245-in. spacing (0.12-in. spacers) 0.61 0.69 0.70 0.78 1.73 67.5 34. 37 NA NA 104.8 70.1 NA CA 06-1002 SR 58 2003 Long DG (no jacks), 0.245-in. spacing (0.12-in. spacers) 0.61 0.69 0.74 0.81 1.87 72.0 36.92 NA NA 105.65 68.85 NA 06-1003 SR 58 2003 Long Groove (0.75-in. spacing, 0.125-in. depth), burlap 0.70 0.78 1.04 1.10 0.72 71.5 39.06 NA NA 104.8 69.45 NA drag 06-1004 SR 58 2003 Long Groove (0.75-in. spacing, 0.25-in. depth), burlap drag 0.78 0.94 1.23 1.30 0.54 73. 0 41.46 NA NA 105.25 69.9 NA 06-1045 SR 58 2003 Long Burlap Drag 0.53 0.63 0.27 0.35 1.70 71.5 35.64 NA NA 104.45 69.3 NA 06-1005 SR 58 2003 Long DG (no jacks), 0.23-in. spacing (0.105-in. spacers) 0.56 0.65 0.73 0.81 1.83 68.5 34.82 NA NA 104.45 67.85 NA 06-1007 SR 58 2003 Long Groove (0.375-in. spacing, 0.25-in. depth), broom 0.64 0.71 1.53 1.58 0.87 67.5 35.98 NA NA 105.6 70.9 NA drag 06-1075 SR 58 2003 Long Broom Drag 0.64 0.71 0.25 0.34 1.77 66.0 24.19 NA NA 105.25 71 NA CO 08-1007 I-70 1994 Long Groove (0.75-in. spacing, 0.125-in. depth), turf drag NA NA 1.28 1.35 0.94 74.5 45.61 NA NA 105.9 69.4 NA 08-1008 I-70 1994 Long Turf Drag NA NA 0.27 0.36 1.70 75.0 38.16 NA NA 104.4 68.6 NA 08-1009 I-70 1994 Long Tine (0.75-in. spacing, 0.125-in. depth), turf drag NA NA 0.82 0.89 1.07 76.5 45.80 NA NA 106.1 69.8 NA 08-3001 US 287 2004 Long Heavy Turf Drag NA NA NA NA NA 92.0 52.41 NA NA 103 69.7 77.85 08-3002 US 287 2004 Long Tine (0.75-in. spacing, 0.1875-in. depth), no NA NA NA NA NA 95.0 54.56 NA NA 104.3 70.3 NA pretexture 08-3003 US 287 2004 Long Meander Tine (0.75-in. spacing, 0.125-in. depth), no NA NA NA NA NA 92.0 56.01 NA NA 104.4 71.3 NA pretexture 08-3004 US 287 2004 Long Groove (0.75-in. spacing, 0.125-in. depth), turf drag NA NA NA NA NA 81.0 44.36 NA NA 104.3 69.21 78.65 08-3005 US 287 2004 Long DG (no jacks), 0.22-in. spacing (0.095-in. spacers) NA NA NA NA NA 89.0 43.79 NA NA 102.8 68.1 NA 08-3006 US 287 2004 Long Tine (0.75-in. spacing, 0.125-in. depth), turf drag NA NA NA NA NA 89.0 50.70 NA NA 103.8 69.9 NA IL 17-1001 I-55/74 2004 Tran Tine (0.75-in. spacing, 0.15-in. depth), turf drag 1.00 1.01 NA NA NA NA NA 32.3 35.83 106.85 70.9 NA 17-4001 I-57 2003 Dense-Graded AC (Superpave) NA NA 0.50 0.57 1.26 66.0 38.85 40.0 NA 102.2 68.1 76.8 17-5001 I-70 2002 Tran Skew Tine (variable spacing, 0.15-in. depth), turf 0.67 0.74 0.47 0.55 1.27 71.5 37.96 30.0 34.11 104.45 69.05 80.95 drag 17-8001 I-74 1998 Dense-Graded AC NA NA 0.68 0.76 1.28 67.0 41.26 38.7 NA 104.3 68.8 NA IA 19-1002 US 163 1993 Tran Tine (0.5-in. spacing, 0.075-in. depth), turf drag 1.06 1.05 NA NA NA NA NA 33.0 36.56 106.35 71.2 NA 19-1003 US 163 1993 Long Tine (0.5-in. spacing, 0.075-in. depth), turf drag 1.03 1.03 NA NA NA NA NA 37.9 41.37 105.4 71.2 NA 19-1004 US 163 1993 Long Tine (0.75-in. spacing, 0.15-in. depth), turf drag 1.03 1.03 NA NA NA NA NA 39.9 43.31 106.1 72.2 NA 19-1061 US 163 1993 Tran Groove (1-in. spacing, 0.18- to 0.25-in. depth), turf 1.05 1.04 NA NA NA NA NA 32.7 36.25 109 74.2 NA drag 19-1007 US 163 1993 Long Turf Drag 1.07 1.06 NA NA NA NA NA 13.7 17.79 105.7 72.1 NA 19-2001 US 34 2004 Long Tine (0.75-in. spacing, 0.125-in. depth), turf drag NA NA 0.63 0.69 1.31 43.03 27.313 49.2 52.91 103.8 71.2 78.6 19-2002 US 34 2004 Long Tine (0.75-in. spacing, 0.125-in. depth), burlap drag NA NA 0.70 0.75 1.13 38.53 26.283 47.7 51.11 105.3 72.2 80.55 19-8001 US 218 1997 Tran Tine (0.75-in. spacing, 0.15-in. depth), turf drag 0.99 0.99 NA NA NA NA NA 53.5 56.46 107.9 71.4 NA 19-8002 US 218 1997 Tran Tine (0.75-in. spacing, 0.15-in. depth), turf drag NA NA NA NA NA NA NA 45.1 48.53 107.5 69.9 NA 19-9002 US 30 2004 Dense-Graded AC (Superpave) NA NA NA NA NA NA NA 26.7 31.21 103.5 68.5 NA (continued on next page)

OCR for page 20
Table 3-5. (Continued). SECT CONST HS PROFILER1 CT METER1 DF TESTER1 LOCKED-WHEEL1 SI INT CPB STATE ID HWY YEAR TEXTURE DESCRIPTION MPD, EMTD, MPD, MTD, NOISE, NOISE, NOISE, 1 1 mm mm mm mm TR DFT(20) F(60) FN40S2 F(60) DB(A) DB(A) DB(A) KS 20-1002 US 69 2004 Long DG (no jacks), 0.235-in. spacing (0.11-in. spacers) & 0.53 0.63 0.77 0.85 2.15 60.5 31.57 43.2 31.14 104.65 72.2 NA standard-sawed joints (FN40R) 20-1004 US 69 2004 Long DG (no jacks), 0.245-in. spacing (0.12-in. spacers) & 0.62 0.70 0.79 0.86 2.29 60.5 33.34 43.3 31.84 105.5 72.55 77.9 single-sawed joints (FN40R) 20-1005 US 69 2004 Long DG (jacks), 0.255-in. spacing (0.13-in. spacers) & 0.63 0.71 0.95 1.01 2.13 64.0 34.74 46.0 33.56 105.3 72.75 NA standard-sawed joints (FN40R) 20-1006 US 69 2004 Long DG (jacks), 0.255-in. spacing (0.13-in. spacers) & 0.63 0.70 0.97 1.03 2.13 62.5 34.27 45.6 33.36 105.4 72.65 NA single-sawed joints (FN40R) 20-1007 US 69 2004 Long DG (no jacks), 0.255-in. spacing (0.13-in. spacers) & 0.61 0.69 0.98 1.04 2.21 62.5 34.08 47.0 34.19 105.1 72.95 NA standard-sawed joints (FN40R) 20-1008 US 69 2004 Long DG (no jacks), 0.255-in. spacing (0.13-in. spacers) & 0.86 0.90 0.91 0.98 2.18 64.5 38.96 45.9 35.52 106.4 74.1 NA single-sawed joints (FN40R) 20-1010 US 69 2004 Long Tine (0.75-in. spacing, 0.15-in. depth), turf drag 0.56 0.65 0.65 0.72 1.22 70.0 35.95 50.8 36.26 105.35 73.4 NA (FN40R) 20-2001 US 54 2004 Ultra-Thin Bonded Wearing Course (0.1875-in. NMAS) NA NA NA NA NA NA NA 39.9 42.98 100.6 69.3 NA 20-4001 I-70 2004 Ultra-Thin Bonded Wearing Course (0.375-in. NMAS) 1.20 1.18 0.94 1.01 1.26 78. 5 47.6 53.4 56.26 103.1 70.4 79 .15 MI 26-1001 I-75 1993 Exposed Aggregate Concrete NA NA NA NA NA NA NA 22.2 26.38 108 70.1 NA MN 27-1001 US 169 1996 Long Tine (0.75-in. spacing, 0.125-in. depth), turf drag 0.77 1.01 NA NA NA NA NA NA NA 105 69.6 NA 27-2003 I-94/694 2003 Long Broom Drag 0.59 0.67 NA NA NA NA NA NA NA 105.7 71.15 NA 27-2004 I-94/694 2004 Long Turf Drag 0.58 0.67 NA NA NA NA NA NA NA 104.9 69.5 NA 27-5001 I-694 1990 Long Turf Drag 0.58 0.66 NA NA NA NA NA NA NA 106.5 71.8 NA 27-7001 US 169 1996 Long Turf Drag 0.61 0.69 0.40 0.48 1.47 71.5 37.67 NA NA 106.8 71.45 NA 27-8001 US 169 1996 Long Tine (0.75-in. spacing, 0.125-in. depth), turf drag 0.89 1.84 0.91 0.98 1.12 75.0 43.65 NA NA 108.15 72.8 NA MO 29-1001 US 36 2004 Tran Tine (0.5-in. spacing, 0.125-in. depth), no pretexture 1.09 1.07 0.64 0.71 1.16 68.0 42.23 NA NA 104.9 69.1 80.25 NC 37-1001 I-40 2004 Ultra-Thin Bonded Wearing Course (0.375-in. NMAS) NA NA 0.82 0.88 1.25 65.5 42.98 50.7 53.30 NA NA NA ND 38-2001 I-94 1999 Long Heavy Turf Drag 0.86 0.89 0.57 0.65 1.22 81.0 46.06 NA NA 110.3 73.1 NA 38-2002 I-94 1999 Tran Tine (variable spacing, 0.1-in. depth), turf drag 0.61 0.69 0.39 0.47 1.77 78.5 40.21 NA NA 105.5 68.85 NA 38-6001 I-94 2000 Tran Skew Tine (variable spacing, 0.15-in. depth), turf 0.90 0.93 0.65 0.73 1.22 67.5 40.20 NA NA 108.5 74.4 NA drag TX 48-1001 I-20 2004 Shotblasted Concrete 0.87 0.90 0.69 0.78 1.76 46.5 30.33 25.3 29.18 108.05 72.55 84 WI 55-1001 US 151 2003 Tran Tine (variable spacing, 0.15-in. depth), turf drag NA NA 0.82 0.88 1.02 80.5 46.49 51.0 54.27 107.3 71.3 82.6 1 Mean values based on right wheelpath and lane center measurements. 2 Smooth tire friction number, unless otherwise noted. 3 Values substantially lower than expected. NA=Not available