Functional design

The functional pavement design involves considerations of skid resistance, roughness, surface distresses, reflectivity of pavement surface etc. The functional pavement design considers mainly the surface features of a pavement.

Drainage design

A road needs to be designed in such a way that the rain/ snow precipitation is drained off the pavement and its surroundings. A suitable surface drainage system for the pavement is designed for this purpose. Some water, however, will percolate into the pavement from its top surface and needs to be taken out of the pavement - this is done by providing an internal drainage system to the pavement. Water will also try to enter into the pavement from bottom due to capillary rise or due to rise in water table. A suitably designed sub-surface drainage system tries to avoid such a problem.