The order of the components of a typical flexible pavement from bottom to top is
1
Prepared soil subgrade, Granular sub-base cum drainage layer, Granular base course, Bituminous binder and/or surface course
2
Prepared soil subgrade, Granular base course, Granular sub-base cum drainage layer, Bituminous binder and/or surface course
3
Granular sub-base cum drainage layer, Prepared soil subgrade, Granular base course, Bituminous binder and/or surface course
4
Granular base course, Bituminous binder and/or surface course. Prepared soil subgrade, Granular sub-base cum drainage layer