The Federal Highway Administration’s Office of Operations prepared this pocket guide to assist transportation professionals in making decisions about the use of traffic control devices, taking into account the unique needs of our Nation’s increasingly elderly population. This guide is intended for use by engineers, technicians, construction contractors, researchers, educators, and others involved in traffic control, roadway design and construction, and transportation. As people age, vision declines, physical fitness and flexibility diminish, the ability to focus attention decreases, and the time necessary to react to unexpected circumstances increases. Each of these changes affects one’s ability to drive safely. For our older population to maintain their mobility without compromising safety, transportation professionals must consider these changes when applying traffic control devices. The goal of this pocket guide is to provide transportation professionals with information on the proper use of traffic control devices with the needs of older roadway users in mind. This guide highlights specific traffic situations that are particularly troublesome for older roadway users, such as left turns and temporary traffic control zones, and provides information on the use of traffic control devices to maximize safety in these circumstances.