Crash test dummies are life-sized mannequins used in vehicle safety testing. They are designed to simulate the human body and measure the impact of collisions during crash tests. These dummies are equipped with sensors that record data on forces experienced during a crash, helping engineers improve vehicle safety features. The data collected from crash test dummies is crucial for developing safer cars and reducing injuries in accidents. They come in various sizes and shapes to represent different ages and body types, including adults, children, and infants. This diversity allows for comprehensive safety assessments across different demographics.