Question Mirrors should be checked: Answers Before every lane change. When changing lanes, but only when other vehicles are nearby. When changing lanes, but only if it is dark outside. Explanation Always check for traffic in your mirrors before changing lanes. Frequent mirror checks should be a part of your normal scanning routine. Take a FREE Practice Test Now This questions appears in the following tests: Idaho Knowledge Test Class A , Maine Knowledge Test Class A , Ohio Knowledge Test Class A , Minnesota Knowledge Test Class B , Michigan Double , Washington Double , Iowa Tank , Wisconsin Passenger ,