Pavement drainage requires consideration of surface drainage, gutter flow, and inlet capacity.
These elements depend on storm frequency and the allowable spread of storm water on the pavement surface. Several decisions are involved in selecting the recurrence interval and spread. The classification of the highway defines the public s expectations regarding water on the pavement surface. Ponding on traffic lanes of high speed, high volume highways is contrary to the publics expectations. Design speed is important to the selection of design criteria.