Table 1. Crashes and environmental related data of the total RTCs during the study period.
| Variable | Frequency | Percentage | |
|---|---|---|---|
| Non-injured vehicular crash | 427643 | 78.78 | |
| Type of crash | Injury | 111832 | 20.60 |
| Death in the scene | 3388 | 0.62 | |
| Total | 542863 | 100.0 | |
| Day | 393310 | 72.45 | |
| Night | 122957 | 22.65 | |
| Scene light | Sunrise | 1252 | 0.23 |
| Sunset | 5660 | 1.04 | |
| Unknown | 19684 | 3.63 | |
| Clear | 471759 | 86.90 | |
| Foggy | 1508 | 0.28 | |
| Snowy | 1761 | 0.32 | |
| Weather | Rainy | 22442 | 4.13 |
| Stormy | 148 | 0.03 | |
| Cloudy | 26198 | 4.83 | |
| Dusty | 217 | 0.04 | |
| Unknown | 18830 | 3.47 | |
| Straight and flat | 346168 | 63.77 | |
| Straight with uphill/downhill | 12827 | 2.36 | |
| Roadway geometrics | Winding road and flat | 16002 | 2.95 |
| Winding road with uphill/downhill | 4862 | 0.90 | |
| Unknown | 163004 | 30.03 | |
| Dry | 492757 | 90.77 | |
| Wet | 25989 | 4.79 | |
| Freezing and snowy | 1280 | 0.24 | |
| Roadway surface | Sandy | 1118 | 0.21 |
| Muddy | 85 | 0.02 | |
| Oily | 29 | 0.01 | |
| Unknown | 21604 | 3.98 | |
| No defect | 204565 | 37.98 | |
| Damaged or defective traffic signs | 30046 | 5.58 | |
| Road narrowing | 22775 | 4.23 | |
| Bumps | 1718 | 0.32 | |
| Unstable shoulders or nonexistent shoulders | 943 | 0.18 | |
| Lack of standard road guard | 1384 | 0.26 | |
| Roadway defect | Partial road collapse | 201 | 0.04 |
| Defective pavements | 376 | 0.07 | |
| Acute angle | 695 | 0.13 | |
| Non-standard grading | 360 | 0.07 | |
| Defective lighting | 968 | 0.18 | |
| Slippery road | 934 | 0.17 | |
| Unknown | 273623 | 50.80 |