Error Score, errors in each driving performance metric and simulated negative driving outcomes
| Teens (n=21) | Adults (n=17) | p Value | |||||
|---|---|---|---|---|---|---|---|
| Possible range | Total sample (n=38) Median (IQR) | Median (IQR) | Teens with ≥1 error in each driving performance metric n (%) | Median (IQR) | Adults with ≥1 error in each driving performance metric n (%) | ||
| Error score | 0–117 | 22.5 (13–36) | 30 (19–36) | 13 (10–32) | 0.02* | ||
| Driving performance metrics | |||||||
| Lane choice | 0–8 | 0 (0–0) | 0 (0–0) | 5 (23.8) | 0 (0–0) | 1 (5.9) | |
| Lateral acceleration during a turn | 0–10 | 2 (0–6) | 2 (1–6) | 16 (76.2) | 2 (0–5) | 11 (64.7) | |
| Speeding | 0–22 | 4 (2–7) | 6 (2–7) | 19 (90.5) | 3 (0–4) | 12 (70.6) | |
| Stopping behaviour at a stop sign | 0–6 | 0 (0–1) | 0 (0–3) | 8 (38.1) | 0 (0–1) | 7 (41.2) | |
| Traffic check | 0–8 | 3 (1–4) | 3 (2–4) | 14 (66.7) | 2 (0–3) | 16 (94.1) | |
| Turn signal | 0–10 | 0 (0–0) | 0 (0–0) | 0 (0) | 0 (0–0) | 3 (17.6) | |
| Yaw | 0–10 | 1 (0–1) | 0 (0–1) | 11 (52.4) | 1 (0–2) | 12 (70.6) | |
| Braking behaviour in a hazardous situation | 0–9 | 2 (1–3) | 3 (2–4) | 21 (100) | 1 (0–2) | 12 (70.6) | |
| Excess glance duration | 0–1 | 0 (0–0) | 0 (0–1) | 6 (28.6) | 0 (0–0) | 3 (17.6) | |
| Gap selection | 0–8 | 6 (4–8) | 6 (5–8) | 8 (38.1) | 6 (4–7) | 8 (47.1) | |
| Headway time | 0–7 | 3 (2–5) | 4 (3–5) | 21 (100) | 2 (1–3) | 13 (76.5) | |
| Scan left for intersection | 0–8 | 3 (1–4) | 4 (3–5) | 20 (95.2) | 1 (0–3) | 15 (88.2) | |
| Scan right for intersection | 0–8 | 3 (2–5) | 4 (2–5) | 21 (100) | 3 (2–4) | 11 (64.7) | |
| Scan hidden hazard | 0–2 | 0 (0–0) | 0 (0–1) | 7 (33.3) | 0 (0–0) | 2 (11.8) | |
| Simulated negative driving outcomes | 0–22 | 0 (0–2) | 0 (0–2) | 0 (0–1) | 0.43 | ||
Note: Error Score is the sum score of errors in driving performance metrics aggregated across potential crash scenarios. Teens and adults had similar distributions of individual errors, error score and simulated negative driving outcomes. Missing Data: For a minority of cases with device calibration failure, eye-tracker-derived measures could not be calculated for the hazard anticipation glances, traffic check and summed excess glance duration (missing data for each measure by scenario ranged from 0% to 21%). Missing data for hazard anticipation glance or traffic check data were imputed from available data in the other scenarios. Given that there was only one event scored for summed excess glance error, missing data for this driving performance error were assigned a non-error.