Table 1.
Descriptive statistics of variables.
| Variable Description | Variable Type | Categories | Frequency | Percent (%) |
|---|---|---|---|---|
| Dependent Variable | ||||
| Crash Injury Severity | Nominal | Fatal Injury | 881 | 7 |
| Nominal | Non-Fatal Injury | 11,685 | 93 | |
| Explanatory Variables | ||||
| Temporal Features | ||||
| Time of crash | Nominal | Peak | 7087 | 56.40 |
| Nominal | Off-peak | 5479 | 43.60 | |
| Day | Nominal | Weekday | 9011 | 71.71 |
| Nominal | Weekend | 3555 | 28.29 | |
| Season | Nominal | Winter | 2754 | 21.92 |
| Nominal | Spring | 1982 | 15.77 | |
| Nominal | Summer | 5313 | 42.28 | |
| Nominal | Autumn | 2517 | 20.03 | |
| Environmental Features | ||||
| Lighting Condition | Nominal | Day | 7601 | 60.49 |
| Nominal | Night | 4965 | 39.51 | |
| Weather | Nominal | Clear | 11,003 | 87.56 |
| Nominal | Rain | 519 | 4.13 | |
| Nominal | Cloudy | 234 | 1.86 | |
| Nominal | Sand storm | 364 | 2.90 | |
| Nominal | others | 446 | 3.55 | |
| Roadway Features | ||||
| Highway Type | Nominal | Divided Highway | 2815 | 22.40 |
| Nominal | Expressway | 9500 | 75.60 | |
| Nominal | Single Highway | 251 | 2.0 | |
| Alignment Type | Nominal | Tangent | 8082 | 64.32 |
| Nominal | Horizontal curve | 503 | 4.0 | |
| Nominal | Vertical curve | 205 | 1.63 | |
| Nominal | Near intersection | 132 | 1.05 | |
| Nominal | others | 3644 | 29.0 | |
| Surface Conditions | Nominal | Good | 7107 | 56.56 |
| Nominal | Cracks | 1257 | 10.0 | |
| Nominal | Debris | 454 | 3.61 | |
| Nominal | wet | 266 | 2.12 | |
| Nominal | others | 3481 | 27.70 | |
| Damage at Site | Nominal | Fence damaged | 2615 | 20.81 |
| Nominal | Barrier damaged | 1272 | 10.12 | |
| Nominal | Pole damaged | 498 | 3.96 | |
| Nominal | Signpost damaged | 307 | 2.44 | |
| Nominal | others | 7875 | 62.67 | |
| Shoulder width (m) | Numeric | Between 2.5–3.0 | 5312 | 42.27 |
| Numeric | Between 3.0–3.5 | 3402 | 27.07 | |
| Numeric | Between 3.5–4.0 | 3853 | 30.66 | |
| Carriageway width (m) | Numeric | <7.5 | 1974 | 15.71 |
| Numeric | between 7.5–11 | 5319 | 42.33 | |
| Numeric | >11 | 5274 | 41.97 | |
| Median width (m) | Numeric | <5 | 1177 | 9.37 |
| Numeric | Between 5–10 | 1061 | 8.44 | |
| Numeric | Between10–15 | 1759 | 14.0 | |
| Numeric | >15 | 8569 | 68.19 | |
| Road Markings | Nominal | Present | 12,264 | 97.60 |
| Nominal | Absent | 302 | 2.40 | |
| Road Cat eyes | Nominal | Present | 12,398 | 98.66 |
| Nominal | Absent | 168 | 1.34 | |
| Traffic Characteristics | ||||
| AADT | Numeric | <2000 (1) | 476 | 3.79 |
| Numeric | Between 2000–5000 (2) | 1282 | 10.20 | |
| Numeric | Between 5000–10000 (3) | 2983 | 23.74 | |
| Numeric | Between 10000–20000 (4) | 7136 | 56.79 | |
| Numeric | >20000 (5) | 687 | 5.47 | |
| Trucks % in ADDT | Numeric | <2% | 607 | 4.83 |
| Numeric | between 2–5% | 993 | 7.90 | |
| Numeric | between 5–10% | 1073 | 8.54 | |
| Numeric | between 10–20% | 6559 | 52.20 | |
| Numeric | between 20–30% | 3335 | 26.54 | |
| Average Speed (kmph) | Numeric | <90 (1) | 529 | 4.21 |
| Numeric | between 90–100 (2) | 2971 | 23.64 | |
| Numeric | between 100–110 (3) | 7467 | 59.42 | |
| Numeric | between 110–120 (4) | 1125 | 8.95 | |
| Numeric | >120 (5) | 474 | 3.78 | |
| Vehicle Features | ||||
| Type of Vehicle at Fault | Nominal | Car | 7516 | 59.81 |
| Nominal | Bus | 940 | 7.49 | |
| Nominal | Small truck | 1250 | 9.95 | |
| Nominal | Big truck | 2104 | 16.74 | |
| Nominal | others | 756 | 6.02 | |
| No. of vehicles involved | Numeric | 1 | 6612 | 52.62 |
| Numeric | 2 | 5518 | 43.91 | |
| Numeric | >2 | 436 | 3.47 | |
| Crash Characteristics | ||||
| Collision Type | Nominal | Automobile Collision | 6512 | 51.82 |
| Nominal | Hit Animal | 174 | 1.39 | |
| Nominal | Hit Pedestrian/ | 58 | 0.46 | |
| Nominal | Rollover | 3158 | 25.13 | |
| Nominal | Run-off the road | 1400 | 11.14 | |
| Nominal | Skidding | 98 | 0.78 | |
| Nominal | Vehicle Burnt | 296 | 2.36 | |
| Nominal | others | 870 | 6.92 | |
| Contributing Circumstance | Nominal | Driver (distractions, fatigue driving, disregard to traffic rules, and TCD) | 9245 | 73.57 |
| Nominal | Animal | 202 | 1.61 | |
| Nominal | Faulty vehicle component | 2120 | 16.87 | |
| Nominal | Poor roadway | 162 | 1.29 | |
| Nominal | others | 837 | 6.66 |