Notes: The figures in round brackets ()
indicate the number of schemes for each treatment type where the cost of
the scheme has been provided by the relevant Local Authority.
The "before" and "after" period is typically 3
years. When the periods are not equal, the annual average number of
accidents for "before" and "after" are compared.
The cost of each scheme has been adjusted to 1999 prices using
adjustment factors presented in Table 2.1 of Economic Trends 2000 (Office
of National Statistics, 2000).
The first year rate of return (1999) is calculated as follows:
Cost of Personal Injury Accident * Average Annual Accidents Saved * 100
/ Cost of scheme (adjusted to 1999).
The Cost of Personal Injury Accident is taken as being £69390. This
figure is taken from DETR's Highways Economics Note (HEN) No.1 and
includes an element for damage only accidents.
