Research Article
Investigating the Differences of Single-Vehicle and Multivehicle Accident Probability Using Mixed Logit Model
Table 3
The estimated results of mixed logit model with four crash categories.
| Variable | Estimated parameter | -statistic |
| Constant [SV] | | | Constant [MV] | | | Constant [SV and MV] | | | Temporal characteristic | | | Weekend [MV] | | | November [MV] | | | 4 a.m.-5 a.m. [MV] | | | Traffic characteristic | | | Low speed limit indicator [MV] | | | Speed gap [SV] | | | Speed gap [MV] | | | Speed gap [SV and MV] | | | Hourly traffic volume [MV] | | | Truck percentage [MV] | | | Road characteristic | | | Number of entering ramps per lane per mile [MV] | | | Curvature [MV] | | | Length of segment [SV] | | | Length of segment [MV] | | | Long remaining service life of rutting [MV] | | | Environmental and road surface characteristic | | | Visibility [SV] | | | Wet road surface [SV] | | | Wet road surface [MV] | | | Chemical wet road surface [MV] | | | Random parameters | | | Mean of log of hourly traffic volume [MV] | | | Std. dev. of log of hourly traffic volume (normal distribution) | | | Mean of inside shoulder width [MV] | | | Std. dev. of inside shoulder width (normal distribution) | | | Mean of wet road surface [MV] | | | Std. dev. of wet road surface (normal distribution) | | | Fit statistics | | | likelihood | | | AIC (smaller is better) | | | BIC (smaller is better) | | |
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