Rate ratio and number of injurious crashes prevented by distance, circle, and route methods
| Shape | Distance band (m) | No of sites* | Expected | Observed | Rate ratio (95% CI) | NP† (95% CI) |
|---|---|---|---|---|---|---|
| *Number of sites with routes extending in both directions into this distance band. | ||||||
| †Number of injurious crashes prevented per site during follow up. | ||||||
| m, metre. | ||||||
| Circle | 0–100 | 101 | 117 | 32 | 0.27 (0.19 to 0.39) | 0.8 (0.7 to 0.9) |
| 100–300 | 101 | 257 | 196 | 0.76 (0.66 to 0.88) | 0.6 (0.3 to 0.9) | |
| 300–500 | 101 | 360 | 358 | 1.00 (0.90 to 1.12) | 0.0 (−0.4 to 0.3) | |
| 500–1000 | 101 | 944 | 914 | 0.97 (0.91 to 1.03) | 0.3 (−0.3 to 0.9) | |
| Route | 0–100 | 101 | 104 | 31 | 0.30 (0.20 to 0.42) | 0.7 (0.6 to 0.8) |
| 100–300 | 90 | 146 | 80 | 0.55 (0.43 to 0.68) | 0.7 (0.5 to 0.9) | |
| 300–500 | 75 | 106 | 63 | 0.59 (0.46 to 0.76) | 0.6 (0.3 to 0.8) | |
| 500–1000 | 58 | 83 | 75 | 0.90 (0.71 to 1.13) | 0.2 (−0.2 to 0.4) | |