Since early roadway construction, pavement surface drainage has been an important consideration in design. For the last 20 years, it has been realized that consideration of subsurface drainage is not only critical, but it is also essential in maintaining the design life of today's roadways. In the past it has been difficult to quantify the effectiveness of subsurface drainage. Much work has been and is being done currently to develop models and methods for doing this. Currently two efforts are ongoing through the National Cooperative Highway Research Program (NCHRP) to provide up-to-date information and methods for design agencies to use in evaluating the effectiveness of subsurface drainage. The seven papers in this volume, which were presented at the 1996 Annual Meeting of the Transportation Research Board, provide both theoretical and field evaluations of the effectiveness of subsurface drainage in extending the life of the roadway system. (A)
Abstract