The Accelerated Aggregate (Road stone) Polishing Machine, often abbreviated as the Accelerated Polishing Machine (APM), is a specialized laboratory testing device used in civil engineering and materials science to evaluate the skid resistance of road aggregates. It simulates the polishing action of vehicle tires on road surfaces to determine the Polished Stone Value (PSV) of aggregates, such as road stone or chippings. This value measures how quickly the aggregate’s surface becomes smooth (polished) under traffic, which is critical for assessing long-term road safety, especially in high-traffic or wet conditions where skid resistance is essential.