Independent Variables | OLS Multiple Linear Regression | Ridge Regression | ||||
Coeff. Estimate | t-Statistics | P-value | Coeff. Estimate | t-statistics | P-value | |
Intercept | 0.4493 |
| 0.000 | 0.1417 |
| 0.000 |
Rd_char 1) Straight 2) U. grade 3) D. grade 4) H. Curve |
0.202 0.471 3.319 2.772 |
0.393 6.794 1.614 2.637 |
0.149 0.222 0.125 0.216 |
0.193 0.513 2.561 3.389 |
0.317 4.312 4.729 9.476 |
0.044 0.001 0.001 0.002 |
Rd_surf 1) Dry 2) Wet 3) Muddy |
−0.482 2.322 1.782 |
0.263 4.866 11.412 |
0.243 0.323 0.193 |
−1.172 1.778 1.914 |
1.489 2.533 8.612 |
0.041 0.002 0.001 |
Weather 1) Clear 2) Rain 3) Snow 4) Fog |
−0.541 6.439 3.743 5.016 |
0.482 6.748 6.188 14.871 |
0.175 0.133 0.202 0.382 |
1.398 2.773 4.493 8.144 |
−1.627 9.163 8.961 7.643 |
0.031 0.003 0.001 0.002 |
Light 1) Day Light 2) Light ON 3) No Light |
2.016 3.153 4.095 |
1.179 3.244 11.877 |
0.092 0.082 0.076 |
0.199 2.371 5.876 |
2.191 5.333 14.742 |
0.007 0.044 0.001 |
Drv_age 1) <21 yr. 2) (21 to 65) 3) >65 yr. |
3.289 −0.541 3.177 |
11.853 1.096 11.847 |
0.004 0.139 0.102 |
4.479 −0.354 7.618 |
17.248 1.435 11.987 |
0.001 0.003 0.002 |
Drv_sex 1) Male 2) Female |
−3.337 −5.228 |
13.449 12.767 |
0.131 0.067 |
−1.899 −2.993 |
11.169 14.119 |
0.002 0.002 |
Vehtype 1) P. Car 2) Van 3) Bus 4) Truck |
−5.301 −2.699 5.890 2.969 |
14.285 13.312 12.449 8.771 |
0.139 0.129 0.102 0.202 |
−5.612 −3.411 4.712 5.844 |
16.339 10.417 8.746 9.352 |
0.044 0.022 0.003 0.002 |
AADT | 6.974 | 3.683 | 0.122 | 4.811 | 6.213 | 0.023 |