Practice question What does an HOV 3 sign mean? There must be at least three people in the vehicleThe lane has three railroad tracksOnly three vehicles may use the lane each hourYou must drive exactly 3 mph Answer: A — There must be at least three people in the vehicle The correct answer is shown above. Try the full quiz for additional practice. Practice more: NM Road Signs Practice Practice Questions - New Mexico Driver License Signs, Signals, and Pavement Markings Practice Exam →