| Parameter | Posterior mean | P-value |
| Intercept | −7.5668 | <0.0001 |
| Log (volume) | 0.5629 | <0.0001 |
| Length | 0.7287 | <0.0001 |
| Speed Diff | 0.0382 | <0.0001 |
| S-curve vs. single curve | −0.3182 | 0.0578 |
| Multiple vs. single curve | 0.2889 | 0.0003 |
| Spring vs. winter | −0.0413 | 0.6621 |
| Summer vs. winter | −0.3927 | 0.0117 |
| Fall vs. winter | −0.2790 | 0.0542 |
| 2005 vs. 2011 | 1.7834 | <0.0001 |
| 2006 vs. 2011 | 1.5176 | <0.0001 |
| 2007 vs. 2011 | 1.3917 | <0.0001 |
| 2008 vs. 2011 | 1.2045 | <0.0001 |
| 2009 vs. 2011 | 0.8893 | 0.0048 |
| 2010 vs. 2011 | 1.2391 | <0.0001 |
| Parameters for probability model | ||
| Intercept | −4.3494 | 0.0053 |
| Speed Diff | 0.1238 | 0.0025 |