Adaptive cruise control (ACC) uses sensors like cameras, lasers, and radar to automatically adjust a vehicle's speed to maintain a safe following distance without the driver having to brake or accelerate. It works by detecting how close the vehicle in front is and adjusting speed accordingly. If an imminent collision is detected, the system warns the driver with visual and audible alerts to brake. Radar sensors measure the distance, velocity, and movement of objects from afar to help ACC determine the shape, position, and motion of vehicles ahead. ACC improves road safety by preventing accidents caused by obstructed views or tailgating.