Clear identification of motor vehicle controls is necessary for safe operation of a vehicle. Identification of some well-known symbols and some new symbols was investigated by a questionnaire. Differences in identification between trained and untrained subjects are shown (employees of a vehicle manufacturer versus factory visitors). Influences of sex, age, and professional education are evaluated. Recommendations for use and further development of symbols such as color and contrast, location, and lighting are given. These findings are compared with the SAE Research Study on the Interpretability of ISO Vehicle Control Symbols, published June 9, 1970.