Practice question What does a red octagonal sign mean on an Iowa road? Come to a complete stopYield only if another vehicle is closeSlow down for a general warningEnter only from the opposite direction Answer: A — Come to a complete stop The correct answer is shown above. Try the full quiz for additional practice. Practice more: Iowa Road Signs Practice Practice Questions - Iowa Driver's License Knowledge Test Road Signs, Signals, and Pavement Markings Practice Exam →