Drug-impaired driving involves driving while in an altered state due to drugs. It is just as bad as driving intoxicated.
The California Office of Traffic Safety explains you can drive drugged when using illegal or legal drugs. Prescription and over-the-counter medications can make you impaired to the point where it is not safe to drive.
If you take cold medication, for example, you may notice a warning on the packaging telling you to not operate heavy machinery or warning that taking the medication could make you drowsy. These notices are telling you that you should not drive after taking the medication.
When you get prescriptions, the bottles usually will have stickers announcing potential side effects or giving you directions on what not to do when using the medication. You should always abide by these warnings. If you must drive when on medication, make sure to talk to your doctor about alternatives that will not hinder your ability to operate a motor vehicle safely.
Since the legalization of marijuana, drugged driving has become a more prominent concern. Just because the drug is legal does not mean it is safe. Marijuana causes similar side effects to alcohol in many people. It can reduce your ability to react and make you sleepy. You should never use before driving and make sure all effects are gone before getting behind the wheel.
While testing for drugged driving is not as easy as testing for a DUI, officers can and will arrest you under suspicion and test you once you get to the jail if they suspect you are under the influence of drugs and operating a vehicle.