| Model | Approach | Variables | Distribution Considered | Correlation Structure |
| 1 | For homogeneous segments, starting from the null model, the other variables were included one by one | AADT Length Radius Lane Width Shoulder Width Day of the Week Age Group Grade | Negative Binomial | Exchangeable |
| 2 | For homogeneous segments, starting from the null model, the other variables were included one by one | AADT Length Radius Lane Width Shoulder Width Grade | Negative Binomial | Exchangeable |
| 3 | For homogeneous segments with VDMA as an offset, the other variables were included, one by one | Length Radius Lane Width Shoulder Width Day of the Week Age Group Grade | Negative Binomial | Exchangeable |
| 4 | For homogeneous segments with VDMA as an offset, the other variables were included, one by one | Length Radius Lane Width Shoulder Width Grade | Negative Binomial | Exchangeable |