| Pattern | Rotation Sums of Squared | |||
| Most influential item category | Total | Percent of variance | The cumulative percentage | |
| 1 | Human factor | 13.114 | 37.214 | 37.214 |
| 2 | Human factor | 9.254 | 21.119 | 58.333 |
| 3 | Human and vehicle factors | 6.215 | 14.406 | 72.739 |
| 4 | Human and vehicle factors | 4.230 | 11.931 | 84.670 |
| 5 | Human factor | 3.880 | 9.314 | 93.984 |