An Implementable Framework for Standardizing National Pavement Crack Measures

National consistent pavement performance measures are essential for MAP-21. Cracks, as the most common type of pavement distresses and an important symptom of potential pavement failure, are a major component of many transportation agencies' pavement performance measures. However, due to the significant diversity among the state DOTs pavement distress protocols, it remains a challenge to establish consistent, nationwide crack measures. State DOTs have, over decades, invested major resources to collect and maintain their legacy data for pavement management and are not willing to change their distress protocols. This paper presents an implementable framework to address this issue using a multi-scale crack analysis concept based on Crack Fundamental Element (CFE). The framework aims to systematically provide physical and topological crack properties using three scales: fundamental crack properties, aggregated crack properties, and CFE cluster geometrical properties. These crack properties are independent from state DOT's protocols, so they can be measured consistently and are flexible enough to transform into the Federal LTPP pavement distress manual and states' legacy protocols through rules and modeling. An actual pavement segment on State Route 236 in Georgia is used to demonstrate the compatibility between the proposed framework and the Georgia DOT COPACES manual; the experimental tests show that these proposed crack measures can be transformed into existing crack definitions with over 90 percent accuracy as compared to human established ground truth. The proposed framework will establish a crucial foundation towards national standardized pavement performance measures.