Practice question A green lane-control arrow over a lane means what? The lane is open for trafficThe lane must be cleared immediatelyThe lane is closed aheadOnly emergency vehicles may use the lane Answer: A — The lane is open for traffic The correct answer is shown above. Try the full quiz for additional practice. Practice more: Oklahoma Road Signs Practice Practice Questions - Oklahoma Written Knowledge Test Road Signs, Signals, and Pavement Markings Practice Exam →