Abstract: Highways, railways, airport runways and levees (dikes) consist of multiple structural layers which ultimately rest on an earthen subgrade. Over time, erosion, nearby construction, weather, seismic activity and other causes can weaken or create gaps in the lower layers including the subgrade. Initially there is no sign of damage on the surface, until the structure subsides, buckles, or even collapses. At present there is no practical way to routinely monitor the condition of the earthen subbase which supports a road, railway or airport runway. In this paper we describe a “smart” geosynthetic which addresses this problem. Our Smartroad Tools ™ geosynthetic can be embedded under pavements and other geotechnical infrastructure during construction or reconstruction. Subsequently, an easy to use and inexpensive sensor array can be used to verify the integrity of the subgrade. This process can provide alerts regarding immediate threats to public safety, as well as longitudinal data for optimizing prevent ive maintenance budgets and activities. We present the results from our laboratory prototypes and full size materials testing, and also describe plans for further stages of testing.