U.S. Department of Transportation
Federal Highway Administration
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Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations
REPORT |
This report is an archived publication and may contain dated technical, contact, and link information |
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Publication Number: FHWA-HRT-14-057 Date: February 2018 |
Publication Number: FHWA-HRT-14-057 Date: February 2018 |
This appendix presents the final crash prediction models organized by land use (mixed-use, commercial, and residential) and crash type (total, injury, turning, rear-end, and right-angle). In most cases, the model form is represented by the equation in figure 18. In these cases, the result is expressed as crashes per mile per year. In other cases, the traffic volume variable is not statistically significant, indicating a linear relationship between traffic volume and crashes. In these limited cases, the model form is reduced to the equation in figure 19, and the result is expressed as crashes per MVMT. The result from the equation in figure 19 is multiplied by MVMT to express the result as crashes per mile per year.
Table 34 through table 36 present three alternate models for mixed-use total crashes. The model form for mixed-use total crashes is shown in figure 18.
Table 34. Alternate model 1 for mixed-use total crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –3.1845 | 1.9550 | 0.1033 |
Region | 1.1410 | 0.2316 | <0.0001 |
AADT | 0.5187 | 0.1819 | 0.0043 |
ACCDENS | 0.0053 | 0.0044 | 0.2279 |
SIGDENS | 0.1095 | 0.0607 | 0.0710 |
PROPLANE1 | –0.5185 | 0.3789 | 0.1711 |
k | 0.5073 | — | — |
Note: The p-values for ACCDENS and PROPLANE1 are larger than desirable. Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 35. Alternate model 2 for mixed-use total crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –3.2905 | 1.8743 | 0.0792 |
Region | 1.0533 | 0.2086 | <0.0001 |
AADT | 0.5266 | 0.1738 | 0.0024 |
UNSIGDENS | 0.0471 | 0.0224 | 0.0354 |
SIGDENS | 0.0957 | 0.0594 | 0.1072 |
PROPLANE1 | –0.6376 | 0.3796 | 0.0931 |
k | 0.4897 | — | — |
Note: Similar model to alternate model 1, but excluding driveways. Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 36. Alternate model 3 for mixed-use total crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –0.8926 | 0.5021 | 0.0755 |
Region | 0.6166 | 0.1013 | <0.0001 |
AADT | 0.3766 | 0.0468 | <0.0001 |
PROPNODEV | –0.4252 | 0.2268 | 0.0608 |
k | 0.5165 | — | — |
Note: This model was developed from the dataset combining all land use types with factor variables representing the land use. Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 37 and table 38 present two alternate models for mixed-use injury crashes. The model form for mixed-use injury crashes is shown in figure 18.
Table 37. Alternate model 1 for mixed-use injury crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –3.5700 | 1.7816 | 0.0451 |
Region | 0.5695 | 0.1980 | 0.0040 |
AADT | 0.5010 | 0.1659 | 0.0025 |
SIGDENS | 0.1239 | 0.0556 | 0.0258 |
PROPLANE1 | –0.5814 | 0.3582 | 0.1046 |
k | 0.4248 | –– | –– |
Note: Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. |
Table 38. Alternate model 2 for mixed-use injury crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –1.7775 | 0.5964 | 0.0029 |
Region | 0.2465 | 0.0931 | 0.0081 |
AADT | 0.3880 | 0.0558 | <0.0001 |
PROPNODEV | –0.3159 | 0.2201 | 0.1511 |
PROPLANE1 | –0.6623 | 0.1404 | <0.0001 |
k | 0.4151 | –– | –– |
Note: The p-value for PROPNODEV is larger than desirable. This model was developed from the dataset combining all land use types with factor variables representing the land use. Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 39 through table 41 present three alternate models for mixed-use turning crashes. The model form for alternate model 1 and model 2 is shown in figure 19. The model form for alternate model 3 is shown in figure 18.
Table 39. Alternate model 1 for mixed-use turning crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –2.1083 | 0.4338 | <0.0001 |
Region | 0.9647 | 0.2843 | 0.0007 |
SIGDENS | 0.1865 | 0.0754 | 0.0134 |
ACCDENS | 0.0088 | 0.0061 | 0.1486 |
k | 0.7920 | — | — |
Note: The p-value for ACCDENS is larger than desirable. Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 40. Alternate model 2 for mixed-use turning crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –2.0792 | 0.3963 | <0.0001 |
Region | 0.8015 | 0.2354 | 0.0007 |
SIGDENS | 0.1797 | 0.0742 | 0.0154 |
UNSIGDENS | 0.0582 | 0.0323 | 0.0719 |
k | 0.7780 | — | — |
Note: Similar model to alternate model 1, but excluding driveways. The overall fit of the model improves, and the p-value for unsignalized intersections is improved. Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 41. Alternate model 3 for mixed-use turning crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –0.4146 | 0.7632 | 0.5870 |
Region | –0.3163 | 0.1301 | 0.0150 |
AADT | 0.2179 | 0.0729 | 0.0028 |
PROPNODEV | –0.5890 | 0.2827 | 0.0372 |
k | 0.7791 | –– | –– |
Note: This model was developed from the dataset combining all land use types with factor variables representing the land use. Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 42 and table 43 present two alternate models for mixed-use rear-end crashes. The model form for mixed-use rear-end crashes is shown in figure 18.
Table 42. Alternate model 1 for mixed-use rear-end crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –6.6976 | 1.9985 | 0.0008 |
Region | 1.2289 | 0.2479 | <0.0001 |
AADT | 0.7901 | 0.1876 | <0.0001 |
SIGDENS | 0.1122 | 0.0702 | 0.1099 |
k | 0.7006 | — | — |
Note: Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 43. Alternate model 2 for mixed-use rear-end crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –3.3091 | 0.6700 | <0.0001 |
Region | 0.8113 | 0.1136 | <0.0001 |
AADT | 0.5015 | 0.0618 | <0.0001 |
SIGDENS | 0.0621 | 0.0380 | 0.1021 |
PROPLANE1 | –0.5548 | 0.1713 | 0.0012 |
k | 0.6098 | — | — |
Note: This model was developed from the dataset combining all land use types with factor variables representing the land use. Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 44 through table 46 present three alternate models for mixed-use right-angle crashes. The model form for mixed-use right-angle crashes is shown in figure 18.
Table 44. Alternate model 1 for mixed-use right-angle crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –5.8048 | 1.9472 | 0.0029 |
Region | 1.8390 | 0.2616 | <0.0001 |
AADT | 0.4656 | 0.1856 | 0.0121 |
ACCDENS | 0.0112 | 0.0051 | 0.0267 |
SIGDENS | 0.2284 | 0.0637 | 0.0003 |
k | 0.5585 | — | — |
Note: Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 45. Alternate model 2 for mixed-use right-angle crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –5.2671 | 2.1768 | 0.0155 |
Region | 1.2134 | 0.2457 | <0.0001 |
AADT | 0.5678 | 0.2103 | 0.0069 |
PROPDIV | –0.4710 | 0.3461 | 0.1736 |
MEDOPDENS | 0.1901 | 0.0884 | 0.0316 |
k | 0.6796 | — | — |
Note: The p-value for PROPDIV is higher than desirable, but the direction of effect for PROPDIV and MEDOPDENS is logical. Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 46. Alternate model 3 for mixed-use right-angle crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –2.1485 | 0.6851 | 0.0017 |
Region | 1.2344 | 0.1377 | <0.0001 |
AADT | 0.2433 | 0.0648 | 0.0002 |
PROPFULLDEV | 0.6787 | 0.1846 | 0.0002 |
k | 0.7674 | — | — |
Note: This model was developed from the dataset combining all land use types with factor variables representing the land use. Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 47 and table 48 present two alternate models for commercial total crashes. The model form for commercial total crashes is shown in figure 18.
Table 47. Alternate model 1 for commercial total crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –0.7017 | 0.6873 | 0.3073 |
Region | 0.8353 | 0.1883 | <0.0001 |
AADT | 0.3094 | 0.0660 | <0.0001 |
ACCDENS | 0.0069 | 0.0048 | 0.1507 |
SIGDENS | 0.1002 | 0.0523 | 0.0556 |
k | 0.4890 | — | — |
Note: The p-value for ACCDENS is higher than desirable. Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 48. Alternate model 2 for commercial total crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –0.6854 | 0.5010 | 0.1713 |
Region | 0.6166 | 0.1013 | <0.0001 |
AADT | 0.3766 | 0.0468 | <0.0001 |
PROPNODEV | –0.4252 | 0.2268 | 0.0608 |
k | 0.5165 | — | — |
Note: This model was developed from the dataset combining all land use types with factor variables representing the land use. Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 49 through table 52 present four alternate models for commercial injury crashes. The model form for commercial injury crashes is shown in figure 18.
Table 49. Alternate model 1 for commercial injury crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –2.0602 | 0.7991 | 0.0099 |
Region | 0.4672 | 0.1815 | 0.0100 |
AADT | 0.3649 | 0.0766 | <0.0001 |
ACCDENS | 0.0085 | 0.0047 | 0.0679 |
SIGDENS | 0.0566 | 0.0512 | 0.2696 |
k | 0.4406 | — | — |
Note: The p-value for SIGDENS is higher than desirable. Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 50. Alternate model 2 for commercial injury crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –0.9792 | 0.8386 | 0.2430 |
Region | 0.2383 | 0.1497 | 0.1113 |
AADT | 0.3225 | 0.0797 | <0.0001 |
PROPNODEV | –0.6472 | 0.3040 | 0.0333 |
PROPLANE1 | –0.6047 | 0.2631 | 0.0216 |
k | 0.4228 | — | — |
Note: Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 51. Alternate model 3 for commercial injury crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | 0.2127 | 0.7288 | 0.7704 |
Region | 0.6769 | 0.1559 | <0.0001 |
AADT | 0.2705 | 0.0697 | 0.0001 |
PROPVC | 0.5421 | 0.1990 | 0.0064 |
PROPLANE1 | –0.6244 | 0.2566 | 0.0150 |
k | 0.4739 | — | — |
Note: Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 52. Alternate model 4 for commercial injury crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –1.9690 | 0.5862 | 0.0008 |
Region | 0.3056 | 0.0923 | 0.0009 |
AADT | 0.3751 | 0.0548 | <0.0001 |
SIGDENS | 0.1075 | 0.0300 | 0.0003 |
PROPLANE1 | –0.5245 | 0.1430 | 0.0002 |
k | 0.3951 | — | — |
Note: This model was developed from the dataset combining all land use types with factor variables representing the land use. Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 53 and table 54 present two alternate models for commercial turning crashes. The model form for commercial turning crashes is shown in figure 18.
Table 53. Alternate model 1 for commercial turning crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –0.9816 | 0.9366 | 0.2946 |
Region | — | — | — |
AADT | 0.1650 | 0.0960 | 0.0855 |
ACCDENS | 0.0110 | 0.0052 | 0.0359 |
SIGDENS | 0.1995 | 0.0660 | 0.0025 |
k | 0.7140 | — | — |
Note: Region is not included; a value of 0 is assumed for all regions. —Not applicable. |
Table 54. Alternate model 2 for commercial turning crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | 0.0085 | 1.1277 | 0.9940 |
Region | –0.2548 | 0.2101 | 0.2251 |
AADT | 0.1947 | 0.1068 | 0.0685 |
PROPNODEV | –0.6967 | 0.4150 | 0.0932 |
PROPLANE1 | –0.7328 | 0.3577 | 0.0405 |
k | 0.7802 | — | — |
Note: Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 55 and table 56 present two alternate models for commercial rear-end crashes. The model form for commercial rear-end crashes is shown in figure 18.
Table 55. Alternate model 1 for commercial rear-end crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –3.2746 | 0.8502 | 0.0001 |
Region | 0.8114 | 0.1786 | <0.0001 |
AADT | 0.5050 | 0.0827 | <0.0001 |
SIGDENS | 0.0924 | 0.0552 | 0.0941 |
k | 0.6055 | — | — |
Note: Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 56. Alternate model 2 for commercial rear-end crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –3.0651 | 0.6691 | <0.0001 |
Region | 0.8113 | 0.1136 | <0.0001 |
AADT | 0.5015 | 0.0618 | <0.0001 |
PROPLANE1 | –0.5548 | 0.1713 | 0.0012 |
SIGDENS | 0.0621 | 0.0380 | 0.1021 |
k | 0.6098 | — | — |
Note: This model was developed from the dataset combining all land use types with factor variables representing the land use. Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 57 and table 58 present two alternate models for commercial right-angle crashes. The model form for commercial right-angle crashes is shown in figure 18.
Table 57. Alternate model 1 for commercial right-angle crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –1.6746 | 0.9312 | 0.0721 |
Region | 1.4756 | 0.2388 | <0.001 |
AADT | 0.1238 | 0.0912 | 0.1745 |
ACCDENS | 0.0165 | 0.0064 | 0.0099 |
SIGDENS | 0.1532 | 0.0658 | 0.0199 |
k | 0.7288 | — | — |
Note: The p-value for AADT is higher than desirable. Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 58. Alternate model 2 for commercial right-angle crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –1.9023 | 0.6838 | 0.0054 |
Region | 1.2344 | 0.1377 | <0.0001 |
AADT | 0.2433 | 0.0648 | 0.0002 |
PROPFULLDEV | 0.6787 | 0.1846 | 0.0002 |
k | 0.7674 | — | — |
Note: This model was developed from the dataset combining all land use types with factor variables representing the land use. Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 59 through table 62 present four alternate models for residential total crashes. The model form for residential total crashes is shown in figure 18.
Table 59. Alternate model 1 for residential total crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –0.5615 | 0.7076 | 0.4275 |
Region | 0.4443 | 0.1533 | 0.0038 |
AADT | 0.3094 | 0.0673 | <0.0001 |
PROPLANE1 | –0.5479 | 0.1702 | 0.0013 |
SIGDENS | 0.1262 | 0.0629 | 0.0449 |
PROPFULLDEV | 0.3371 | 0.2317 | 0.1456 |
k | 0.3277 | — | — |
Note: The p-value for PROPFULLDEV is larger than desirable. Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 60. Alternate model 2 for residential total crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –0.4764 | 0.7211 | 0.5088 |
Region | 0.3824 | 0.1499 | 0.0108 |
AADT | 0.3025 | 0.0685 | <0.0001 |
PROPLANE1 | –0.5260 | 0.1722 | 0.0023 |
SIGDENS | 0.1576 | 0.0622 | 0.0113 |
k | 0.3384 | — | — |
Note: This model is the same as alternate model 1 but without PROPFULLDEV. Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 61. Alternate model 3 for residential total crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –1.3644 | 0.4953 | 0.0059 |
Region | 0.6850 | 0.1107 | <0.0001 |
AADT | 0.3883 | 0.0463 | <0.0001 |
ACCDENS | 0.0032 | 0.0022 | 0.1375 |
k | 0.5181 | — | — |
Note: This model was developed from the dataset combining all land use types with factor variables representing the land use; region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 62. Alternate model 4 for residential total crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –1.1048 | 0.4876 | 0.0235 |
Region | 0.6166 | 0.1013 | <0.0001 |
AADT | 0.3766 | 0.0468 | <0.0001 |
PROPNODEV | –0.4252 | 0.2268 | 0.0608 |
k | 0.5165 | — | — |
Note: This model was developed from the dataset combining all land use types with factor variables representing the land use; region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 63 and table 64 present two alternate models for residential injury crashes. The model form for residential injury crashes is shown in figure 18.
Table 63. Alternate model 1 for residential injury crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –2.7357 | 0.8556 | 0.0014 |
Region | 0.1656 | 0.1423 | 0.2447 |
AADT | 0.4189 | 0.0820 | <0.0001 |
PROPLANE1 | –0.4040 | 0.1669 | 0.0155 |
SIGDENS | 0.2081 | 0.0539 | 0.0001 |
k | 0.2663 | — | — |
Note: Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 64. Alternate model 2 for residential injury crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –2.7379 | 0.9147 | 0.0028 |
Region | 0.2303 | 0.1603 | 0.1509 |
AADT | 0.4615 | 0.0867 | <0.0001 |
PROPLANE1 | –0.6125 | 0.1715 | 0.0004 |
PROPFULLDEV | 0.3720 | 0.2273 | 0.1017 |
k | 0.3220 | — | — |
Note: region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 65 through table 68 present four alternate models for residential turning crashes. The model form for residential turning crashes is shown in figure 18.
Table 65. Alternate model 1 for residential turning crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –2.5087 | 1.0439 | 0.0163 |
Region | — | — | — |
AADT | 0.2949 | 0.1008 | 0.0034 |
UNSIGDENS | 0.0589 | 0.0289 | 0.0416 |
SIGDENS | 0.2173 | 0.0845 | 0.0101 |
k | 0.6710 | — | — |
Note: Region is not included; a value of 0 is assumed for all regions. —Not applicable. |
Table 66. Alternate model 2 for residential turning crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –1.1275 | 1.1225 | 0.3152 |
Region | –0.6520 | 0.2073 | 0.0017 |
AADT | 0.1826 | 0.1059 | 0.0846 |
UNSIGDENS | 0.0635 | 0.0283 | 0.0247 |
SIGDENS | 0.2244 | 0.0818 | 0.0061 |
k | 0.5792 | — | — |
Note: This model is the same as alternate model 1 but with the Region variable included. Note the large reduction in the AADT parameter; region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 67. Alternate model 3 for residential turning crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –0.9528 | 0.7286 | 0.1910 |
Region | –0.1651 | 0.1339 | 0.2174 |
AADT | 0.1759 | 0.0708 | 0.0130 |
ACCDENS | 0.0052 | 0.0028 | 0.0643 |
SIGDENS | 0.1821 | 0.0426 | <0.0001 |
k | 0.7030 | — | — |
Note: This model was developed from the dataset combining all land use types with factor variables representing the land use; region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 68. Alternate model 4 for residential turning crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –0.7154 | 0.7477 | 0.3387 |
Region | –0.3163 | 0.1301 | 0.0150 |
AADT | 0.2179 | 0.0729 | 0.0028 |
PROPNODEV | –0.5890 | 0.2827 | 0.0372 |
k | 0.7791 | — | — |
Note: This model was developed from the dataset combining all land use types with factor variables representing the land use; region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 69 through table 71 present three alternate models for residential rear-end crashes. The model form for residential rear-end crashes is shown in figure 18.
Table 69. Alternate model 1 for residential rear-end crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –3.8941 | 0.9816 | <0.0001 |
Region | 0.5803 | 0.1984 | 0.0034 |
AADT | 0.5392 | 0.0945 | <0.0001 |
SIGDENS | 0.1675 | 0.0864 | 0.0527 |
k | 0.5541 | — | — |
Note: Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 70. Alternate model 2 for residential rear-end crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –2.6180 | 1.0221 | 0.0104 |
Region | 0.5406 | 0.1865 | 0.0037 |
AADT | 0.4782 | 0.0967 | <0.0001 |
PROPLANE1 | –0.8174 | 0.2078 | <0.0001 |
PROPTWLTL | –0.5600 | 0.2439 | 0.0217 |
k | 0.4803 | — | — |
Note: Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 71. Alternate model 3 for residential rear-end crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –3.3056 | 0.6549 | <0.0001 |
Region | 0.8113 | 0.1136 | <0.0001 |
AADT | 0.5015 | 0.0618 | <0.0001 |
PROPLANE1 | –0.5548 | 0.1713 | 0.0012 |
SIGDENS | 0.0621 | 0.0380 | 0.1021 |
k | 0.6098 | ||
Note: This model was developed from the dataset combining all land use types with factor variables representing the land use; region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 72 through table 74 present three alternate models for residential right-angle crashes. The model form for residential right-angle crashes is shown in figure 18.
Table 72. Alternate model 1 for residential right-angle crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –1.8958 | 1.1271 | 0.0926 |
Region | 0.8655 | 0.2364 | 0.0003 |
AADT | 0.2357 | 0.1098 | 0.0319 |
k | 0.7812 | — | — |
Note: Region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 73. Alternate model 2 for residential right-angle crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –1.4079 | 1.0732 | 0.1896 |
Region | 0.8858 | 0.2180 | <0.0001 |
AADT | 0.1332 | 0.1051 | 0.2049 |
SIGDENS | 0.2267 | 0.0750 | 0.0025 |
PROPLANE1 | –0.3633 | 0.2383 | 0.1274 |
PROPFULLDEV | 0.4295 | 0.3125 | 0.1693 |
k | 0.5555 | — | — |
Note: The p-values for AADT, PROPLANE1, and PROPFULLDEV are higher than desirable; region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |
Table 74. Alternate model 3 for residential right-angle crashes.
Variable | Estimate | Standard Error | p-Value |
---|---|---|---|
Intercept | –2.1173 | 0.6540 | 0.0012 |
Region | 1.1970 | 0.1314 | <0.0001 |
AADT | 0.1768 | 0.0639 | 0.0057 |
SIGDENS | 0.2084 | 0.0390 | <0.0001 |
ACCDENS | 0.0044 | 0.0028 | 0.1078 |
k | 0.6790 | — | — |
Note: This model was developed from the dataset combining all land use types with factor variables representing the land use; region is included for North Carolina or Minnesota; a value of 0 if in Northern or Southern California. —Not applicable. |