Incorporating Traffic Speed Deflection Data in Pavement Management Decision Making for Flexible Pavements

Systematic pavement condition evaluation and development of an optimized set of pavement treatment strategies are two key tasks in the pavement management process that assists in making informed decisions on future construction actions. Current State Highway Agency's pavement management systems are primarily based on surface condition data, and surface cracking is mainly used as an indicator of the pavement structural condition. However, with effective pavement preservation activities that intervene early to preserve and extend the life of pavements and increasingly thicker long-life pavements, the surface cracks can no longer be a reliable indicator of structural condition of the pavement structure. This study envisions the use of data from Traffic Speed Deflection Devices (TSDD) in network level structural assessment and optimizing the pavement treatment strategies for flexible pavements within a modern pavement management framework. The methodology used the tensile strain at the bottom of the asphalt layer predicted from TSDD measurements to evaluate structural deterioration well before the occurrence of surface cracks, enabling more optimum treatment intervention. Mechanistic analyses were used to predict treatment benefits as a function of time and pavement condition at the time of application. The methodology allows the pavement engineer to identify an optimized series of treatment types and their timing over an analysis horizon that minimizes the life cycle cost while maintaining an above acceptable level of service. Finally the study illustrates the effectiveness of Remaining Service Interval (RSI) concept for consistent reporting of future construction needs based on optimum time remaining until a defined treatment type.