The twin problems of protecting a road pavement from damage by water and of designing it to perform satisfactorily for many years under anticipated environmental conditions is the essence of road design. The report is about internal drainage; it is about water that enters the road structure directly from above the road pavement (including shoulders) or directly from
below. The purposes of the report are:
(a) to identify the areas of uncertainty in knowledge concerning internal drainage
(b) to describe the problems
(c) to illustrate current thinking
(d) to promote best practice, as far as it can be defined and
(e) to draw conclusions about the most cost-effective methods of reducing the risk of problems caused by water.
Finally the report proposes a way forward to resolve the uncertainties.
Rational road drainage design. (2000)