LTPP Data Analysis: Improving Use of FWD and Longitudinal Profile Measurements (2024)

Chapter: Appendix J: Influencing Factors for FWD Deflection Measurements

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Suggested Citation: "Appendix J: Influencing Factors for FWD Deflection Measurements." National Academies of Sciences, Engineering, and Medicine. 2024. LTPP Data Analysis: Improving Use of FWD and Longitudinal Profile Measurements. Washington, DC: The National Academies Press. doi: 10.17226/28570.
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APPENDIX J

Influencing Factors for FWD Deflection Measurements

Temperature

The following provides the AIC and regression analysis results for temperature adjustment on FWD measured deflections.

Table J-14. Variable Selection Using Minimum AIC — D1

Factor Estimate nDF SS F Ratio Prob > F
Intercept -0.0063 1 0.0000 0.0000 1.0000
Asphalt layer thickness -0.0008 1 0.0002 5.89 0.0159
Climatic zone (all) -0.0015 3 0.0008 6.97 0.0001
Climatic zone (DF and DNF) -0.0014 3 0.0008 6.97 0.0001
Climatic zone (WF, DF, and DNF) -0.0008 3 0.0008 6.97 0.0001
Layer 2 temperature 0.0000 1 6.5e-6 0.1630 0.6862
PSC level (all categories) -0.0025 3 0.0023 19.61 5e-12
PSC level (good and excellent} 0.0009 3 0.0023 19.61 5e-12
PSC level (good, excellent, and poor) -0.0014 3 0.0023 19.61 5e-12
Total rainfall 0.0000 1 9.4e-6 0.2370 0.6268
Total thickness 0.0000 1 9.5e-6 0.2390 0.6251

Table J-15. Regression Results for Temperature Adjustment — D1

Factor Estimate Std Error L-R Chi Sq Prob > Chi Sq Lower Limit Upper Limit
Intercept -0.0089 0.0003 681.0071 <.0001 -0.0096 -0.0083
Asphalt layer thickness (thick) -0.0007 0.0003 7.9053 0.0049 -0.0013 -0.0002
Asphalt layer thickness (thin) – – – – – –-
Climatic zone (DF) 0.0009 0.0004 4.7989 0.0285 0.0018 -0.0001
Climatic zone (DNF) – – – – – –
Climatic zone (WF) -0.0012 0.0004 8.2685 0.0040 0.0020 0.0004
Climatic zone (WNF) 0.0020 0.0005 14.5432 0.0001 0.0010 0.0031
PSC level (excellent) -0.0025 0.0004 34.4892 <.0001 -0.0033 -0.0016
PSC level (fair) 0.0033 0.0005 36.7573 <.0001 0.0023 0.0044
PSC level (good) -0.0013 0.0005 7.8137 0.0052 -0.0022 -0.0004
PSC level (poor) – – – – – –

Note: “—” is the baseline variable for categorical variables. “L-R Chi Sq” is Likelihood Ratio Chi-Square.

Page 258
Suggested Citation: "Appendix J: Influencing Factors for FWD Deflection Measurements." National Academies of Sciences, Engineering, and Medicine. 2024. LTPP Data Analysis: Improving Use of FWD and Longitudinal Profile Measurements. Washington, DC: The National Academies Press. doi: 10.17226/28570.
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Table J-16. Variable Selection Using Minimum AIC — D2

Factor Estimate nDF SS F Ratio Prob > F
Intercept -0.0048 1 0.0000 0.0000 1.0000
Asphalt layer thickness (all) -0.0008 1 0.0002 12.54 0.0004
Climatic zone (all) -0.0007 2 0.0002 5.39 0.0049
Climatic zone (DF and WNF) 0.0000 1 1.8e-5 1.02 0.3139
Climatic zone (DNF and WF) 0.0009 1 0.0001 5.97 0.0149
Layer 2 temperature 0.0000 1 2.1e-5 1.18 0.2785
PSC level (excellent, good, and poor) -0.0006 2 0.0002 4.36 0.0134
PSC level (excellent, good, fair, and poor) -0.0022 3 0.0011 20.54 1.8e-12
PSC level (good and excellent) 0.0007 1 0.0001 5.46 0.0199
Total rainfall 0.0004 1 0.0000 1.95 0.1634
Total thickness (all) 0.0008 1 0.0001 7.74 0.0056

Table J-17. Regression Results for Temperature Adjustment — D2

Factor Estimate Std Error L-R Chi Sq Prob > Chi Sq Lower Limit Upper Limit
Intercept 0.0006 0.0013 0.2187 0.6400 -0.0020 0.0032
Asphalt layer thickness (thick) 0.0074 0.0012 38.8111 <.0001 0.0051 0.0098
Asphalt layer thickness (thin) – – – – – –
Climatic zone (DF) 0.000 0.0016 0.2006 0.6542 -0.0025 0.0039
Climatic zone (DNF) – – – – – –
Climatic zone (WF) -0.0153 0.0023 42.7150 <.0001 -0.0199 -0.0107
Climatic zone (WNF) 0.0085 0.0023 14.2643 0.0002 0.0041 0.0130
PSC (excellent) -0.0064 0.0020 10.0836 0.0015 -0.0103 -0.0024
PSC (fair) 0.0069 0.0020 12.2550 0.0005 0.0030 0.0107
PSC (good) -0.0032 0.0016 3.9537 0.0468 -0.0065 0.0000
PSC (poor) – – – – – –

Note: “—” is the baseline variable for categorical variables.

Table J-18. Variable Selection Using Minimum AIC — D3

Factor Estimate nDF SS F Ratio Prob > F
Intercept -0.0054 1 0.0000 0.0000 1.0000
Asphalt layer thickness (all) -0.0008 1 0.0002 8.13 0.0046
Climatic zone (all) 0.0000 3 0.0000 0.2230 0.8801
Climatic zone (DF and WF) 0.0000 3 0.0000 0.2230 0.8801
Climatic zone (WNF and DNF) 0.000 3 0.0000 0.2230 0.8801
Layer 2 temperature 3.9e-5 1 7.5e-5 3.39 0.0664
PSC level (all) -0.0031 1 0.0011 50.74 5.5e-12
PSC level (excellent and good) 0.0000 2 6.5e-5 1.4550 0.2347
PSC level (excellent, good, and poor) 0.0000 2 6.5e-5 1.4550 0.2347
Total rainfall 0.000 1 1.5e-5 0.6850 0.4084
Total thickness (all) -0.0007 1 0.0001 6.09 0.0140
Page 259
Suggested Citation: "Appendix J: Influencing Factors for FWD Deflection Measurements." National Academies of Sciences, Engineering, and Medicine. 2024. LTPP Data Analysis: Improving Use of FWD and Longitudinal Profile Measurements. Washington, DC: The National Academies Press. doi: 10.17226/28570.
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Table J-19. Regression Results for Temperature Adjustment D3

Factor Estimate Std Error L-R Chi Sq Prob > Chi Sq Lower Limit Upper Limit
Intercept 0.0005 0.0008 0.3995 0.5273 -0.0011 0.0022
Asphalt layer thickness (thick) 0.0040 0.0007 29.3120 <.0001 0.0026 0.0055
Asphalt layer thickness (thin) – – – – – –
Climatic zone (DF) 0.0003 0.0011 0.0675 0.7950 -0.0019 0.0024
Climatic zone (DNF) – – – – – –
Climatic zone (WF) -0.0074 0.0013 32.206 <.0001 -0.0099 0.0048
Climatic zone (WNF) 0.0038 0.0016 5.5799 0.0182 0.0006 0.0069
PSC level (excellent) -0.0021 0.0012 3.2258 0.0725 -0.0043 0.0002
PSC level (fair) 0.0049 0.0012 15.6609 <.0001 0.0025 0.0074
PSC level (good) -0.0037 0.0010 14.5561 0.0001 -0.0056 -0.0018
PSC level (poor) – – – – – –

Note: “—” is the baseline variable for categorical variables.

Table J-20. Variable Selection for Using Minimum AIC — D4

Factor Estimate nDF SS F Ratio Prob > F
Intercept -0.0049 1 0.0000 0.0000 1.0000
Asphalt layer thickness (thick-thin) -0.0010 1 0.0002 8.2460 0.0044
Climatic zone (DF-DNF} -0.0007 3 0.0003 3.5360 0.0152
Climatic zone (WF, DF, DNF-WNF} -0.0007 3 0.0003 3.5360 0.0152
Climatic zone (WF-DF and DNF) -0.0008 3 0.0003 3.5360 0.0152
Layer 2 temperature 6e-5 1 0.0002 6.3690 0.0121
PSC (good, excellent, and poor-fair) -0.0024 3 0.0009 12.8310 6e-8
PSC (good and excellent-poor) -0.0001 3 0.0009 12.8310 6.48e-8
PSC (good-excellent) 0.0004 4 0.0009 12.8310 6.48e-8
Total rainfall 0.0000 1 8.8e-7 0.0370 0.8480
Total thickness (thick-thin) 0.0010 1 0.0001 4.7820 0.0295

Table J-21. Regression Results for Temperature Adjustment — D4

Factor Estimate Std Error L-R Chi Sq Prob > Chi Sq Lower Limit Upper Limit
Intercept -0.0004 0.0005 0.5004 0.4793 -0.0014 0.0007
Asphalt layer thickness (thick) 0.0013 0.0004 9.9067 0.0016 0.0005 0.0021
Asphalt layer thickness (thin) – – – – – –
Climatic zone (DF) 0.0011 0.000 2.6545 0.1033 0.0002 0.0024
Climatic zone (DNF) – – – – – –
Climatic zone (WF) -0.0020 0.000 8.9832 0.002 -0.0033 -0.000
Climatic zone (WNF) 0.0005 0.0010 0.3271 0.5674 -0.0013 0.0024
PSC level (excellent) 0.0003 0.0006 0.2811 0.5960 -0.0009 0.0015
PSC level (fair) 0.0025 0.0008 9.2582 0.0023 0.0009 0.0042
PSC level (good) -0.0024 0.0006 14.6490 0.0001 -0.0036 -0.0011
PSC level (poor) – – – – – –

Note: “—” is the baseline variable for categorical variables.

Page 260
Suggested Citation: "Appendix J: Influencing Factors for FWD Deflection Measurements." National Academies of Sciences, Engineering, and Medicine. 2024. LTPP Data Analysis: Improving Use of FWD and Longitudinal Profile Measurements. Washington, DC: The National Academies Press. doi: 10.17226/28570.
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Table J-22. Variable Selection for Using Minimum AIC — D5

Factor Estimate nDF SS F Ratio Prob > F
Intercept 0.0001 1 0.0000 0.0000 1.0000
Asphalt layer thickness (all) -0.0017 1 0.0005 22.60 3.1e-6
Climatic zone (all) -0.0013 3 0.0006 8.75 1.4e-5
Climatic zone (DF and WF) -0.0005 3 0.0006 8.7470 1.4e-5
Climatic zone (WNF and DNF) -0.0013 3 0.0006 8.75 1.4e-5
Layer 2 temperature 0.0000 1 3.1e-6 0.1470 0.7019
PSC level (all) -0.0017 3 0.0004 5.80 0.0007
PSC level (excellent and poor) -0.0001 3 0.0004 5.80 0.0007
PSC level (excellent, good, and poor) 0.0003 3 0.0004 5.80 0.0007
Total rainfall 0.0000 1 1.2e-6 0.0560 0.8138
Total thickness (all) 0.0012 1 0.0001 7.05 0.0084

Table J-23. Regression Results for Temperature Adjustment — D5

Factor Estimate Std Error L-R Chi Sq Prob > Chi Sq Lower Limit Upper Limit
Intercept 0.0000 0.0005 0.0005 0.9820 -0.0009 0.0009
Asphalt layer thickness (thick) 0.0007 0.0003 4.7268 0.0297 0.0001 0.0014
Asphalt layer thickness (thin) – – – – – –
Climatic zone (DF) 0.000 0.0006 1.3755 0.2409 -0.0004 0.0018
Climatic zone (DNF) – – – – – –
Climatic zone (WF) -0.0008 0.0006 1.9099 0.1670 -0.0019 0.0003
Climatic zone (WNF) -0.0008 0.0008 1.1583 0.2818 -0.0023 0.0007
PSC level (excellent) 0.0008 0.0006 1.9078 0.1672 -0.0003 0.0019
PSC level (fair) 0.0021 0.0007 8.2073 0.0042 0.0007 0.0036
PSC level (good) -0.0010 0.0005 3.3446 0.0674 -0.0020 0.0001
PSC level (poor) – – – – – –

Note: “—” is the baseline variable for categorical variables.

Table J-24. Variable Selection Using Minimum AIC — D6

Factor Estimate nDF SS F Ratio Prob > F
Intercept 0.0009 1 0.0000 0.0000 1.0000
Asphalt layer thickness (all) 0.0000 1 3.6e-5 1.4720 0.2263
Climatic zone (all) -0.0018 3 0.0010 13.31 5.2e-8
Climatic zone (DNF and WF) -0.0011 3 0.0010 13.31 5.2e-8
Climatic zone (WNF and DF) -0.0013 3 0.0010 13.31 5.2e-8
Layer 2 temperature 0.0000 1 1.3e-5 0.5440 0.4616
PSC level (all) -0.0023 3 0.0011 14.52 1.2e-8
PSC level (excellent and good) -0.0009 3 0.0011 14.52 1.2e-8
PSC level (excellent, good, and poor) -0.0024 3 0.0011 14.52 1.2e-8
Total rainfall 0.0000 1 1.3e-5 0.5550 0.4573
Total thickness (all) 0.0000 1 2.2e-7 0.0090 0.9237
Page 261
Suggested Citation: "Appendix J: Influencing Factors for FWD Deflection Measurements." National Academies of Sciences, Engineering, and Medicine. 2024. LTPP Data Analysis: Improving Use of FWD and Longitudinal Profile Measurements. Washington, DC: The National Academies Press. doi: 10.17226/28570.
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Table J-25. Regression Results for Temperature Adjustment — D6

Factor Estimate Std Error L-R Chi Sq Prob > Chi Sq Lower Limit Upper Limit
Intercept 0.0002 0.0003 0.3115 0.5768 -0.0005 0.0008
Asphalt layer thickness (thick) -0.0002 0.0003 0.8698 0.3510 -0.0007 0.0003
Asphalt layer thickness (thin) – – – – – –
Climatic zone (DF) -0.0003 0.0005 0.4968 0.4809 -0.0012 0.0006
Climatic zone (DNF) – – – – – –
Climatic zone (WF) 0.0006 0.0004 2.3335 0.1266 -0.0002 0.0015
Climatic zone (WNF) -0.0009 0.0005 3.5489 0.0596 -0.0019 0.0000
PSC level (excellent) 0.0005 0.0005 1.2914 0.2558 -0.0004 0.0014
PSC level (fair) 0.0004 0.0006 0.6249 0.4292 -0.0007 0.0016
PSC level (good) 0.0006 0.0004 1.8312 0.1760 -0.0003 0.0014
PSC level (poor) – – – – – –

Note: “—” is the baseline variable for categorical variables.

Moisture

The following provides the AIC and regression analysis results for moisture adjustment on FWD measured deflections.

Table J-26. Variable Selection Using Minimum AIC — D1

Factor Estimate nDF SS F Ratio Prob > F
Intercept 2.24 1 0.0000 0.0000 1.0000
Average base moisture 0.0000 1 0.8525 1.4480 0.2290
Average subgrade moisture 0.0334 1 41.79 70.96 7.7e-17
Average deep subgrade moisture -0.0117 1 9.10 15.44 8.8e-5
Climatic zone (all) -0.2579 3 60.83 34.43 1.4e-21
Climatic zone (DNF, WNF, and WF) -0.1487 3 60.83 34.43 1.4e-21
Climatic zone (WNF and WF) -0.1181 3 60.83 34.43 1.4e-21
Total rainfall 0.0404 1 1.45 2.46 0.1168

Table J-27. Regression Results for Moisture Adjustment — D1

Factor Estimate Std Error L-R Prob > Lower Upper
Chi Sq Chi Sq Limit Limit
Intercept 2.1714 0.0440 2432.48 <.0001 2.09 2.26
Average subgrade moisture 0.0225 0.0018 149.61 <.0001 0.0189 0.0261
Climatic zone (DF) 0.2769 0.0313 78.18 <.0001 0.2155 0.3383
Climatic zone (WF) 0.0822 0.0284 8.39 0.0038 0.0265 0.1378
Climatic zone (WNF) -0.0371 0.0340 1.19 0.2744 -0.1038 0.0295
Climatic zone (DNF) – – – – – –
Total rainfall 0.0493 0.0256 3.72 0.0539 0.0008 0.0994
Page 262
Suggested Citation: "Appendix J: Influencing Factors for FWD Deflection Measurements." National Academies of Sciences, Engineering, and Medicine. 2024. LTPP Data Analysis: Improving Use of FWD and Longitudinal Profile Measurements. Washington, DC: The National Academies Press. doi: 10.17226/28570.
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Table J-28. Variable Selection Using Minimum AIC —D2

Factor Estimate nDF SS F Ratio Prob > F
Intercept 2.08 1 0.0000 0.0000 1.0000
Average base moisture -0.0113 1 3.98 8.64 0.0034
Average subgrade moisture 0.0264 1 22.76 49.33 3.3e-12
Average deep subgrade moisture -0.0042 1 0.9508 2.06 0.1514
Climatic zone (all) -0.2554 3 33.3963 24.13 3.1e-15
Climatic zone (WNF, WF, and DF) -0.1217 3 33.40 24.13 3.1e-15
Climatic zone (WNF and WF) -0.0784 3 33.40 24.13 3.1e-15
Total rainfall 0.0492 1 1.618 3.51 0.0614

Table J-29. Regression Results for Moisture Adjustment — D2

Factor Estimate Std Error L-R Chi Sq Prob > Chi Sq Lower Limit Upper Limit
Intercept 2.08 0.0399 2719.54 <.0001 2.00 2.16
Average subgrade moisture 0.0228 0.0017 186.86 <.0001 0.0195 0.0261
Climatic zone (DF) 0.2658 0.0284 87.42 <.0001 0.2101 0.3216
Climatic zone (WF) 0.1099 0.0257 18.30 <.0001 0.0595 0.1603
Climatic zone (WNF) -0.0825 0.0308 7.18 0.0074 -0.1428 -0.0221
Climatic zone (DNF) – – – – – –
Total rainfall 0.0433 0.0231 3.50 0.0612 -0.0021 0.0886

Table J-30. Variable Selection Using Minimum AJC —D3

Factor Estimate nDF SS F Ratio Prob > F
Intercept 1.8212 1 0.0000 0.0000 1.0000
Average base moisture 0.0000 1 0.2883 0.6130 0.4338
Average subgrade moisture 0.0234 1 16.49 35.07 4.1e-9
Average deep subgrade moisture -0.0050 1 1.38 2.94 0.0866
Climatic zone (all) -0.3252 3 58.95 41.8010 9.7e-26
Climatic zone (WNF, WF, and DF) -0.1693 3 58.95 41.8010 9.7e-26
Climatic zone (WNF and WF) -0.1063 3 58.95 41.8010 9.7e-26
Total rainfall 0.0562 1 2.0044 4.26 0.0391

Table J-31. Regression Results for Moisture Adjustment —D3

Factor Estimate Std Error L-R Chi Sq Prob > Chi Sq Lower Limit Upper Limit
Intercept 1.9120 0.0376 2591.9840 <.0001 1.8383 1.9856
Average subgrade moisture 0.0240 0.0016 233.0114 <.0001 0.0209 0.0271
Climatic zone (DF) 0.2824 0.0266 112.7459 <.0001 0.2302 0.3345
Climatic zone (WF) 0.1339 0.0241 30.8306 <.0001 0.0866 0.1812
Climatic zone (WNF) -0.1459 0.0288 25.6953 <.0001 -0.2024 -0.0895
Climatic zone (DNF) – – – – – –
Total rainfall 0.0640 0.0216 8.7618 0.0031 0.0216 0.1065
Page 263
Suggested Citation: "Appendix J: Influencing Factors for FWD Deflection Measurements." National Academies of Sciences, Engineering, and Medicine. 2024. LTPP Data Analysis: Improving Use of FWD and Longitudinal Profile Measurements. Washington, DC: The National Academies Press. doi: 10.17226/28570.
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Table J-32. Variable Selection Using Minimum AIC —D4

Factor Estimate nDF SS F Ratio Prob > F
Intercept 1.69 1 0.0000 0.0000 1.0000
Average base moisture -0.0084 1 1.79 4.04 0.0447
Average subgrade moisture 0.0272 1 54.65 123.31 3.5e-27
Average deep subgrade moisture 0.0000 1 0.0484 0.1090 0.7413
Climatic zone (all) -0.3030 3 60.92 45.82 7.6e-28
Climatic zone (DNF and WNF) -0.2116 3 60.92 45.82 7.6e-28
Climatic zone (WF and DF) -0.0927 3 60.92 45.82 7.6e-28
Total rainfall 0.1012 1 4.54 10.24 0.0014

Table J-33. Regression Results for Moisture Adjustment — D4

Factor Estimate Std Error L-R Chi Sq Prob > Chi Sq Lower Limit Upper Limit
Intercept 1.6823 0.0347 2357.01 <.0001 1.61 1.75
Average subgrade moisture 0.0234 0.0014 260.55 <.0001 0.0206 0.0262
Climatic zone (DF) 0.2943 0.0247 141.52 <.0001 0.2458 0.3429
Climatic zone (WF) 0.1615 0.0224 51.87 <.0001 0.1176 0.2055
Climatic zone (WNF) -0.1675 0.0267 39.27 <.0001 -0.2200 -0.1151
Climatic zone (DNF) – – – – – –
Total rainfall 0.0778 0.0201 14.93 0.0001 0.0383 0.1173

Table J-34. Variable Selection Using Minimum AIC — D5

Factor Estimate nDF SS F Ratio Prob > F
Intercept 1.53 1 0.0000 0.0000 1.0000
Average base moisture -0.0091 1 2.21 6.6990 0.0098
Average subgrade moisture 0.0224 1 51.46 155.90 1.2e-33
Climatic zone (all) -0.3040 3 65.97 66.61 1e-39
Climatic zone (DNF and WNF) -0.1430 3 65.97 66.61 1e-39
Climatic zone (WF and DF) -0.0489 3 65.97 66.61 1e-39
Total rainfall 0.1447 1 8.21 24.88 7.1e-7

Table J-35. Regression Results for Moisture Adjustment — D5

Factor Estimate Std Error L-R Chi Sq Prob > Chi Sq Lower Limit Upper Limit
Intercept 1.4129 0.0370 1460.04 <.0001 1.3404 1.4854
Average subgrade moisture 0.0225 0.0015 217.48 <.0001 0.0195 0.0255
Climatic zone (DF) 0.3049 0.0261 136.64 <.0001 0.2537 0.3560
Climatic zone (WF) 0.1988 0.0240 68.80 <.0001 0.1518 0.2457
Climatic zone (WNF) -0.1306 0.0279 21.98 <.0001 -0.1852 -0.0760
Climatic zone (DNF) – – – – – –
Total rainfall 0.0816 0.0208 15.36 <.0001 0.0408 0.1224
Page 264
Suggested Citation: "Appendix J: Influencing Factors for FWD Deflection Measurements." National Academies of Sciences, Engineering, and Medicine. 2024. LTPP Data Analysis: Improving Use of FWD and Longitudinal Profile Measurements. Washington, DC: The National Academies Press. doi: 10.17226/28570.
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Table J-36. Variable Selection Using Minimum AIC — D6

Factor Estimate nDF SS F Ratio Prob > F
Intercept 0.8800 1 0.0000 0.0000 1.0000
Average base moisture -0.0052 1 0.6082 2.2220 0.1364
Average subgrade moisture 0.02149 1 38.06 139.04 4.3e-30
Climatic zone (all) -0.2951 3 39.31 47.87 7.3e-29
Climatic zone (WNF, WF, and DF) -0.1522 3 39.31 47.87 7.3e-29
Climatic zone (WNF and WF) -0.1256 3 39.31 47.87 7.3e-29
Total rainfall 0.1292 1 9.25 33.79 8.3e-9

Table J-37. Regression Results for Moisture Adjustment — D6

Factor Estimate Std Error L-R Chi Sq Prob > Chi Sq Lower Limit Upper Limit
Intercept 0.9901 0.0627 250.09 <0.0001* 0.8672 1.11
Intercept 0.8206 0.0359 521.5993 <.0001 0.7501 0.8910
Average subgrade moisture 0.0248 0.0015 286.7422 <.0001 0.0219 0.0276
Climatic zone (DF) 0.3735 0.0248 227.5699 <.0001 0.3250 0.4221
Climatic zone (WF) 0.1531 0.0238 41.4474 <.0001 0.1065 0.1997
Climatic zone (WNF) -0.0838 0.0266 9.9442 0.0016 -0.1359 -0.0317
Climatic zone (DNF) – – – – – –
Page 257
Suggested Citation: "Appendix J: Influencing Factors for FWD Deflection Measurements." National Academies of Sciences, Engineering, and Medicine. 2024. LTPP Data Analysis: Improving Use of FWD and Longitudinal Profile Measurements. Washington, DC: The National Academies Press. doi: 10.17226/28570.
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Suggested Citation: "Appendix J: Influencing Factors for FWD Deflection Measurements." National Academies of Sciences, Engineering, and Medicine. 2024. LTPP Data Analysis: Improving Use of FWD and Longitudinal Profile Measurements. Washington, DC: The National Academies Press. doi: 10.17226/28570.
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Suggested Citation: "Appendix J: Influencing Factors for FWD Deflection Measurements." National Academies of Sciences, Engineering, and Medicine. 2024. LTPP Data Analysis: Improving Use of FWD and Longitudinal Profile Measurements. Washington, DC: The National Academies Press. doi: 10.17226/28570.
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Suggested Citation: "Appendix J: Influencing Factors for FWD Deflection Measurements." National Academies of Sciences, Engineering, and Medicine. 2024. LTPP Data Analysis: Improving Use of FWD and Longitudinal Profile Measurements. Washington, DC: The National Academies Press. doi: 10.17226/28570.
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Suggested Citation: "Appendix J: Influencing Factors for FWD Deflection Measurements." National Academies of Sciences, Engineering, and Medicine. 2024. LTPP Data Analysis: Improving Use of FWD and Longitudinal Profile Measurements. Washington, DC: The National Academies Press. doi: 10.17226/28570.
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Suggested Citation: "Appendix J: Influencing Factors for FWD Deflection Measurements." National Academies of Sciences, Engineering, and Medicine. 2024. LTPP Data Analysis: Improving Use of FWD and Longitudinal Profile Measurements. Washington, DC: The National Academies Press. doi: 10.17226/28570.
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Suggested Citation: "Appendix J: Influencing Factors for FWD Deflection Measurements." National Academies of Sciences, Engineering, and Medicine. 2024. LTPP Data Analysis: Improving Use of FWD and Longitudinal Profile Measurements. Washington, DC: The National Academies Press. doi: 10.17226/28570.
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Page 264
Suggested Citation: "Appendix J: Influencing Factors for FWD Deflection Measurements." National Academies of Sciences, Engineering, and Medicine. 2024. LTPP Data Analysis: Improving Use of FWD and Longitudinal Profile Measurements. Washington, DC: The National Academies Press. doi: 10.17226/28570.
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Page 264
Next Chapter: Guidelines for Adjusting FWD Deflections on Asphalt Pavements to Account for Temperature and Moisture Conditions
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