This distress identification manual (DIM) provides a common language for describing cracks, potholes, rutting, spalling, and other pavement distresses being monitored by the LTPP program. Highway agencies at all levels of government can and are using the DIM to standardize pavement condition data collection, produce consistent pavement condition ratings, and train their pavement managers in data collection procedures. Implementation of the DIM enables highway agencies to collect data on roads without spending valuable resources developing their own nomenclature, definitions, severity levels, and measurement methods. It also allows a common understanding among practitioners of the definition of pavement distress features.