Target ranges for structures, pedestrians, and vehicles. Vehicular, pedestrian, and structural targets are categorized by their frequency or monetary value. For example, the probability of a vehicle or pedestrian occupying a target area in target range 4 is between the lower and upper limits of 1/10,000 and 1/500. Using the value of a “hypothetical life” of £1,000,000 the structure value within the target range 4 is £101–2,000.
| Target range | Structure (repair value)* | Pedestrian frequency | Vehicular frequency | Probability ratioz |
|---|---|---|---|---|
| 1 | (a) Very high value (b) Habitable | > 36 per hour–constant | (a) Motorway (b) Trunk road, built-up and non-built-up areas (c) Principal road, built-up area | 1/1 |
| 2 | High value | 10–36 per hour | Principal roads, non-built up-area | 1/20 |
| 3 | Moderate–high value | 1–9 per hour | Minor roads, moderate use or poor visibility | 1/100 |
| 4 | Moderate value | < 1 per hour | Minor roads, low use and good visibility | 1/500 |
| 5 | Low value | ≤ 1 per day | Minor private roads and tracks (no data available) | 1/10,000 |
| 6 | Very low value | ≤ 1 per week | None | 1/120,000 |
↵* Structure values represent the likely cost of repair or replacement. Very high = £50,001–1,000,000; high = £10,001–50,000; moderate–high = £2,001–10,000; moderate = £101–2000; low = £11–100: very low = ≤£10.