Research Article

Comparison of Factors Affecting Crash Severities in Hit-and-Run and Non-Hit-and-Run Crashes

Table 4

NHR multinomial logistic regression model results.

VariablesInjury crashes vs. PDO crashesFatal crashes vs. PDO crashes
EstimateP valueOdds ratio (95% CI)EstimateP valueOdds ratio (95% CI)

Intercept-2.7490.000ā€‰-7.2720.000ā€‰

Lighting condition (relative to daylight)

Dawn------
Dusk------
Darkness0.1580.0291.171(1.017, 1.350)0.9230.0462.516(1.016, 6.230)
Darkness, lighted road0.2880.0001.333(1.245, 1.427)0.9520.0002.590(1.523, 4.407)

Road surface condition (relative to dry)

Wet------
Snow or slush-0.3420.0000.710(0.610, 0.827)---

Number of units involved (relative to one unit)

2 units------
More than 2 units1.4540.0004.279 (2.952, 6.203)1.7370.0255.678(1.240, 25.994)

Crash type (relative to fixed object crash)

Head on------
Sideswipe opposite direction-0.9190.0000.399(0.262, 0.607)---
Pedal cyclist2.5050.00012.247(8.401, 17.853)---
Pedestrian3.0930.00022.037(15.118, 32.123)1.9860.0157.288(1.474, 36.030)
Angle-0.4810.0090.618(0.432, 0.885)-2.5660.0020.077(0.015, 0.389)
Turning-0.8080.0000.446(0.312, 0.637)-2.8700.0010.057(0.011, 0.287)
Sideswipe same direction-2.0490.0000.129(0.089, 0.186)-3.8630.0000.021(0.003, 0.151)
Parked motor vehicle-1.6490.0000.192(0.133, 0.277)-1.9270.0100.146(0.033, 0.636)
Rear end-1.2860.0000.276(0.193, 0.395)-3.8810.0000.021(0.004, 0.115)

Trafficway type (relative to non-divided road)

Divided with median barrier0.2110.0001.235(1.165, 1.310)---
One-way-0.2370.0000.789(0.715, 0.871)---
Parking lot-1.1890.0000.305(0.253, 0.366)---

Crash damage in dollar value (relative to $500 or less)

$501 - $1500------
Over $15001.2250.0003.405(3.035, 3.821)2.3510.00010.494(3.653, 30.144)

Crash hour (relative to non-peak hour)

AM peak hour------
PM peak hour-0.1940.0000.823(0.764, 0.887)-1.0990.0190.333(0.133, 0.837)

Crash day of week (relative to weekday)

Weekend0.1200.0001.128(1.060, 0.199)---

-2Log-likelihood for the model with only the intercept: 24375.043
-2Log-likelihood for the final model: 13620.463
Goodness of fit test: deviance = 9318.845, P = 1.000
Pseudo-R2: Cox & Snell = 0.142; Nagelkerke = 0.483; McFadden = 0.320
Overall prediction accuracy: 90.5%