The Texas Transportation Institute has announced their findings on perpetual pavement tests conducted by the Texas Department of Transportation (TxDOT) over the past several years. In 2000, the TxDOT began constructing sections of eight heavily traveled roadways, mainly on I-35 between Laredo and Dallas, with thick, 15-inch to 20-inch asphalt layers placed over thick subgrade layers in a design known as perpetual pavement. The only maintenance necessary would be the occasional need to provide a new riding surface, effecting a cost savings over the estimated 50-year lifespan.

With a Texas Transportation Institute (TTI) evaluation of these projects well under way, Flexible Pavements Program Manager Tom Scullion announced his findings that perpetual pavements in Texas are holding up well. Scullion began his analysis in 2004, testing core samples and evaluating readings taken from non-destructive techniques using Ground Penetrating Radar and Falling Weight Deflectometers, according to a TTI announcement. The nondestructive testing and lab work determines the structural capacity of the current perpetual pavements.

Scullion and TTI Assistant Research Scientist Wenting Liu developed a software program (FPS 21) that will be used to determine optimal structural design for future perpetual pavements in Texas.