VAA Virginia Asphalt Fall/Winter 2021

26 FALL/WINTER 2021 Current photo of today’s award winning section on I81. sections of I-81 in the area, states, “Clearly one significant factor in the performance of this roadway section was daylighting the subbase stone from edge to edge beyond the shoulders during original construction. This undoubt- edly helped get water away from the weak in situ subgrade soils and formed a strong foundation for the pavement.” Another distinct factor in the performance of this roadway section was the targeted installation of cross drains (CD). These drains were placed at all cut/fill sections and bridge structure interfaces to ensure proper subsurface drainage throughout the mountainous terrain. Forensics associated with these drains have repeatedly high- lighted this system’s effectiveness, which is continued in modern designs today. Lastly, it is important to emphasize that the traffic levels seen today on Interstate 81 are significantly greater than the designers ever envisioned back in the 1950s. Traffic vol- umes have exponentially increased over the years, particularly since the deregulation of the trucking industry following the Motor Carrier Act of 1980, clearly something that the original designers could not have envi- sioned. Yet, the pavement still performs well today due to the decisions made during design and the steps put in place during construction. Fortunately for VDOT, much of Interstate 81 benefits from these and other design and construction methodologies that have assisted in its pavement structures’ long- term/perpetual performance. This is evi- denced by VDOT’s winning two Perpetual Pavement Awards; both have come from I-81 (the last being in 2006 for a section in Frederick County). As we continue building new infrastructure and rebuilding our existing pavements, we must pull out all the stops to ensure a sus- tainable pavement system. Recognizing that sustainability and long-term pavement per- formance go hand in hand is critical. “One of the keys to sustainability is long life,” said Amy Miller, PE, national director of the APA. “Asphalt roads can be engineered to last indefinitely with only routine maintenance and periodic surface renewal (1).” References 1. Asphalt Pavement Alliance (APA) website https:// www.driveasphalt.org/awards/perpetual-by-performance A PICTURE OF SUSTAINABILITY △ continued from page 24