Time after implementation (years) | Low casualty roads | High casualty roads | ||||
---|---|---|---|---|---|---|
Benefit per km of road (£) (SD) | NPV (90% credible limits) | Percent of zones with positive NPV* | Benefit per km of road (£) (SD) | NPV (90% credible limits) | Percent of zones with positive NPV* | |
5 | 23344 (3668) | −36117 (−128225 to 20862) | 41 | 78940 (14660) | 18947 (−75252 to 82021) | 74 |
10 | 37278 (5905) | −22183 (−114294 to 35289) | 53 | 127299 (24232) | 67306 (−29157 to 137890) | 85 |
*Societal benefits outweigh costs.