<p><p><h2>Preferred Design Procedure</h2>The current design procedure assumes the drainage layer is fully saturated; however, it may not always be the case in field. A constant drainage capacity is assumed in the current design, but the drainage capacity may change during the service life. These aspects should be included in the future design procedure. The current design procedure should be transitioned to the M-E design format.</p><p>The Federal Highway Administration (FHWA) has a set of design documents for this technology. The documents are summarized below.</p><p><table class='tablepress' id='tablepress-302'><thead><th><center>Publication Title</th><th><center>Publication
Year
</th><th><center>Publication Number</th><th><center>Available for Download</th></thead><tbody><tr><td >Geotechnical Aspects of Pavements</td><td ><center>2006</td><td ><center>FHWA NHI-05-037</td><td ><center>Yes<sup>1</td></tr><tr><td >Geosynthetic Design and Construction Guidelines</td><td ><center>2008</td><td ><center>FHWA NHI-07-092</td><td ><center>No<sup>2</td></tr></tbody></table><br><p class="disclaimer"><sup>1</sup> <a href="http://www.fhwa.dot.gov/engineering/geotech/pubs/05037/05037.pdf">http:… class="disclaimer"><sup>2</sup> <a href="http://www.nhi.fhwa.dot.gov/training/nhistore.aspx">http://www.nhi.fhwa…;
<p><p><h2>References</h2>AASHTO (1993). “<em>AASHTO Guide for Design of Pavement Structures.</em>” American Association of State Highway and Transportation Officials, Washington, D.C.</p><p>AASHTO (2006). “<em>Standard Specifications for Geotextiles - M 288</em>.” Standard Specifications for Transportation Materials and Methods of Sampling and Testing, 26<sup>th</sup> Edition, American Association of State Transportation and Highway Officials, Washington, D.C.</p><p>Holtz, R.D., Christopher, B.R., and Berg, R.R. (2008). “Geosynthetic design and construction guidelines.” <em>Report No. FHWA-NHI-07-092, U.S. Department of Transportation,</em> National Highway Institute, Federal Highway Administration, Washington.</p><p>Christopher, B.R., Schwartz, C., and Boudreau, R. (2006). “Geotechnical aspects of pavements.” Report No. FHWA NHI-05-037, <em>U.S. Department of Transportation,</em> National Highway Institute, Federal Highway Administration, Washington.</p><p>Mallela, J., Larson, G., Wyatt, T., Hall, J., and Barker, W. (2002). “User’s guide for drainage requirements in pavements- DRIP 2.0 microcpmpouter program.” <em>U.S. Department of Transportation,</em> Federal Highway Administration, Washington.</p><p>Christopher, B.C., and Zhao, A. (2001). “Design manual for roadway geocomposite underdrain systems.” <em>Roadway Geocomposite Underdrain Systems.</em></p><p> </p><p> </p><p><strong> </strong></p></p>