SELECTION CRITERIA

To be included in the list a junction or 100 metre length of road must have a minimum of five personal injury accidents in the most recent three-calendar-year period.

Longer lengths of road qualify for inclusion if N >= L*(0.3+(9.4/(L+1))), where
N=number of accidents in the most recent three-year period
L = length of road in metres divided by 100

For example, a 200 metre length of road qualifies if N >= 2*(0.3+(9.4/(2+1))) i.e. 7 or more accidents required.

ACCIDENT SITE SCORE

Once selected, the score for a junction or 100 metre length of road is four times the number of fatal accidents + three times the number of serious accidents + the number of slights (4*fatal+3*serious+slight)

For longer lengths of road the score (rounded to the nearest whole number) =

((4F+3Se+Sl)/L)*(5/(0.3+(9.4/(L+1))))

where F = number of fatal accidents, Se = number of serious accidents and Sl = number of slight accidents.

For example, for a 200 metre length of road with one fatal, three serious and four slight accidents in three years, the score =
(((4*1)+(3*3)+4)/2)*(5/(0.3+(9.4/(2+1))))=12