Soil Modification or Soil Stabilization can be used in new construction or reconstruction. Soil Modification or Soil Stabilization is used with FDR or base stabilization to allow treatment of drainage issues and deep subgrade instability (greater than 2 feet below the existing surface). For both new construction and reconstruction, the service life of a pavement with a modified or stabilized subgrade is dependent on a good structural design. With reconstruction the adequacy of the selected treatment to mitigate the existing distress impacts the service life as well. The limiting factor of a well designed and constructed pavement with a modified or stabilized subgrade is often the life expectancy of the wearing surface and not the subgrade layer. In optimum application situations, many agencies see their modified/stabilized treatments lasting 25 plus years.