If your faculties are impaired by alcohol or drugs, the law doesn’t just prohibit you from driving a vehicle, but also from having the care or control of a vehicle. Here are some examples of acts that may result in the same consequences as driving while impaired:

• Being seated in the driver's seat, even if the vehicle is stopped.
• Being in one's car (even sleeping in the back seat) and having the possibility of starting the vehicle.
• Being close to one's vehicle (e.g. removing snow, putting things in the trunk or listening to the radio).

However, if you haven’t been drinking, and you’re too tired to drive, it is better to sleep before hitting the road.