Driving is a very important duty that you must only take on when you are fully able to pay attention to the road and react appropriately to what is going on around your vehicle. Being impaired by any substance isn't going to allow you to do this.
When you think of impaired driving, you might automatically think of alcohol. This is far from the only substance that can have this impact on your driving abilities. Prescriptions, over-the-counter medications and illegal drugs can also affect you to the point where you are unable to safely drive.
What substances impair driving?
Many different substances can have impacts that impair your ability to drive safely. Different ones can have different effects. You may not even have to ingest something for it to change your driving abilities. Think about a trip to the eye doctor. They can dilate your eyes, which can make it impossible for you to see properly.
For example, marijuana might delay your reaction speed. Certain prescriptions might make you dizzy. You should be on the lookout for any substance that might make you drowsy, dizzy or overly relaxed. Some medications and drugs make it hard for you to move your limbs and digits normally. Essentially, anything that makes it more difficult for you to drive should be avoided.
How do police officers gauge impairment?
Police officers remain watchful for their entire shift. The same signs of drunk driving that they look for also apply to impairment from other drugs. These include drifting between lanes, crossing the center line, driving after dark without headlights, stopping suddenly and hitting objects near the road. Other signs might also be present.
When you are pulled over because an officer thinks you are impaired, they must determine if you are and what is the cause. When you have been drinking, a blood alcohol concentration test is done to determine whether you are above the legal limit of .08 percent. This isn't so easy when the source is something else.
Blood, urine, fingernail and hair follicle testing can show the presence of drugs and medications. However, these don't show the level of impairment. It is possible for a person to test positive for one of these substances even though they aren't actually impaired by them at the moment. This is because they will remain in the person's system for a long time after they are taken.
All of these factors can come into the picture when you are planning your defense. Be sure you consider everything from the reason for the stop through the results of the test.