| Variable | No injury accidents | Injury or fatal accidents | ||
| Parameter | t-statistic | Parameter | t-statistic | |
| Poisson model | ||||
| Constant | −0.1531 | −1.69 | −0.6315 | −2.16 |
| Passenger car volume | 0.00028 | 15.32 | −0.00011 | −1.13 |
| Heavy vehicle volume | 0.00018 | 0.82 | −0.00026 | −1.92 |
| Light non-passenger car vehicle volume | 0.00054 | 13.10 | 0.00074 | 6.85 |
| Traffic speed | 0.00687 | 8.05 | 0.00351 | 1.51 |
| Number of lanes | 0.1901 | 8.74 | −0.1521 | 2.81 |
| Number of horizontal curves | 0.3221 | 24.14 | 0.5268 | 14.31 |
| Number of access roads | 0.1354 | 18.08 | 0.0781 | 3.43 |
| Negative binomial model | ||||
| Constant | −0.8012 | −3.11 | −0.9245 | −2.80 |
| Passenger car volume | 0.00036 | 5.42 | −0.00011 | −1.15 |
| Heavy vehicles volume | −0.00001 | −0.08 | −0.00019 | −1.27 |
| Light non-passenger car vehicles volume | 0.00066 | 4.93 | 0.0010 | 6.30 |
| Traffic speed | 0.01053 | 4.51 | 0.0043 | 1.43 |
| Number of lanes | 0.2359 | 3.50 | −0.0971 | −1.20 |
| Number of horizontal curves | 0.3715 | 6.90 | 0.5031 | 9.52 |
| Number of access roads | 0.1743 | 6.75 | 0.09701 | 3.32 |
| Dispersion parameter | 1.0921 | 17.67 | 0.7718 | 7.65 |