ABSTRACT
There are many ways water can flow over, into, and through road s tructures (Figure 8.1), and the flows can be anything from inconvenient to catastrophic. Water flowing across or along the road surface can be erosive, disrupting the integrity of the surface, and presenting an uncomfortable and potentially dangerous ride for vehicle operators. Water getting into the road structure can weaken the subgrade and pavement layer granular materials sufficiently to cause failure in the form of deep ruts, potholes, and/or punch-outs.
