CASE LAW - Basi v The Superintendent of Motor Vehicles
Spencer Basi was stopped while driving a motor vehicle under the influence of marihuana. A Standardized Field Sobriety Test was conducted after an initial questioning by the arresting officer. Mr. Basi showed symptoms consistent with marihuna impairment, was prohibited from driving for 24 hours and had his vehicle impounded for a similar time period.

A study by researchers at the University of Florida reports that you may have only had one glass of wine with dinner, but if you’re an older driver (aged 55+), that single serving may hit you hard enough to make you a dangerous driver.
Australia's Transport Accident Commission in Victoria state has published The Cell, an anti-drugged driving video that is part of a TV advertising campaign there. In their typically hard hitting style the video shows a young male driver taking drugs at a party and the consequences of that choice on the drive home afterward.
The case of Lutter v Smithson arises from a fatal collision following a 19th birthday party. An impaired guest drove away from the party and caused a crash that killed a taxi driver and injured his passenger. The party hosts asked the court for a summary judgment dismissing all claims against them.
This short video from New Zealand examines 3 Maori boys waiting in a car for their father to return. They parody the father driving while under the influence of marihuana (blazed) during the wait. It is humourous on the face of it, but if you really think about it they are really keenly aware of the dangers of drug impaired driving.