Table 3.
Model estimation and marginal effects for crashes involving in-state large truck drivers.
| Category | Variables | Parameter estimate | -score | Marginal effects |
||
|---|---|---|---|---|---|---|
| Severe Injury |
Minor Injury |
No Injury |
||||
| [SI] | [MI] | [NI] | ||||
| Random parameter | ||||||
| Rural or Urban | Rural [SI] | -1.010 | -1.45 | 0.0354 | -0.0083 | -0.0271 |
| Standard deviation of “Rural” (normally distributed) | 2.210 | 3.58 | ||||
| Heterogeneity in means of random parameter | ||||||
| Highway Classification | Interstate | -0.570 | -1.8 | |||
| Driver race | Caucasian | 0.492 | 2.27 | |||
| Heterogeneity in variance of random parameter | ||||||
| First harmful event | Collision with a tree | 0.631 | 3.02 | |||
| Defined for severe injury | ||||||
| Primary contributing factor | Ran off-road | 0.458 | 1.72 | 0.0014 | -0.0003 | -0.0011 |
| First harmful event | Collision with a ditch | 0.876 | 2.68 | 0.0023 | -0.0006 | -0.0017 |
| Most harmful event | Rollover | 1.332 | 6.59 | 0.0163 | -0.0041 | -0.0122 |
| Intersection | Yes | -0.407 | -2.74 | -0.006 | 0.0012 | 0.0048 |
| Opposing Lane Separation | Metal/cable barrier | -0.725 | -2.64 | -0.003 | 0.0006 | 0.0024 |
| Locale | Shopping or business area | -0.641 | -3.44 | -0.0042 | 0.0007 | 0.0035 |
| Driver residence distance | More than 25 miles | -0.279 | -2.08 | -0.0062 | 0.0014 | 0.0048 |
| Road Condition | Wet | -0.357 | -1.76 | -0.0018 | 0.0004 | 0.0014 |
| Lighting condition | Daylight | -0.858 | -5.5 | -0.0255 | 0.0055 | 0.0201 |
| Dark without streetlights | -0.660 | -2.95 | -0.0046 | 0.0011 | 0.0035 | |
| Defined for minor severity | ||||||
| Primary contributing factor | Fatigue | 0.516 | 2.63 | -0.0002 | 0.0022 | -0.002 |
| Ran traffic signal | 1.484 | 7.06 | -0.0001 | 0.0051 | -0.0049 | |
| Overcorrection | 0.578 | 2.4 | -0.0002 | 0.0016 | -0.0015 | |
| Swerved to avoid animal | 0.626 | 2.02 | -0.0001 | 0.0009 | -0.0008 | |
| Defective equipment | -0.611 | -3.99 | 0.0003 | -0.0041 | 0.0039 | |
| Highway Classification | Federal | 0.330 | 3.67 | -0.0006 | 0.009 | -0.0085 |
| County | 0.307 | 2.73 | -0.0006 | 0.0062 | -0.0056 | |
| Functional class | Major collector | 0.196 | 1.82 | -0.0003 | 0.0036 | -0.0033 |
| Locale | Open Country | 0.254 | 3.58 | -0.0017 | 0.0206 | -0.0189 |
| Road curvature | Curve left and level | 0.347 | 2.05 | -0.0002 | 0.0019 | -0.0017 |
| Manner of crash | Single vehicle | 0.447 | 5.51 | -0.0021 | 0.0222 | -0.0201 |
| Defined for no injury | ||||||
| Constant | 2.024 | 24.82 | ||||
| Primary contributing factor | Improper load/size | 1.217 | 1.95 | -0.0001 | -0.0004 | 0.0005 |
| Ran stop sign | -1.591 | -3.46 | 0.0002 | 0.0009 | -0.0011 | |
| Manner of crash | Rear-end | -0.709 | -8.97 | 0.0044 | 0.0227 | -0.027 |
| Highway Classification | State | -0.241 | -3.1 | 0.0024 | 0.0081 | -0.0105 |
| Opposing Lane Separation | Concrete barrier | -0.294 | -2.69 | 0.0006 | 0.0041 | -0.0046 |
| Airbag status | Deployed | 0.258 | 3.94 | -0.0032 | -0.0146 | 0.0178 |
| number of observations | 6943 | |||||
| Log-likelihood at convergence | -4480.001 | |||||
| Log-likelihood at zero | -7627.665 | |||||
| McFadden Pseudo R-sq | 0.413 | |||||