"First, let's define 'impairment.' Webster's New World Dictionary defines impairment as "making something worse, less, weaker, or damaged." Applied to driving, impairment means there is a factor present that decreases your ability to operate your vehicle safely.
The first thing that comes to most folks' minds is impairment through alcohol or other drugs. There are others as well: impairment through fatigue, or as a result of disabling injuries or illness."
Lots of bad or fatal accidents in our area are caused by sleepy drivers. Sleepiness can be as bad as drugs or alchohol. Don't let it be you! And we know of all the problems caused by prescription drugs. Don't underestimate their power to make you an unsafe driver. In my newsman days I probably saw as many fatal one-vehicle crashes as anything. They almost always involved impairment of some kind.