Is using a turn signal while changing lanes the law or just common courtesy?
While you certainly wouldn’t know it from watching the majority of drivers out there, using a turn signal to indicate a lane change is generally the law. In your home state of Massachusetts, the applicable traffic code states: Every person operating a motor vehicle, before stopping said vehicle or making any turning movement which would affect the operation of any other vehicle, shall give a plainly visible signal by activating the brake lights or directional lights or signal as provided on said vehicle… So if you have ’em, the law says use ’em! If your particular vehicle isn’t equipped with “directional lights” (commonly known as turn signals or blinkers), then you are required to use the appropriate arm signal. Failure to do so can cost you a fine, not to mention the eternal hatred of your fellow drivers.
