I don't believe the problem is entirely that people take drink too lightly; I think it's *driving* people take for granted, especially in North America. Our communities are built for car travel and the driver's licence is our standard accepted identification document for an adult. A fully fit adult who lives anywhere but a dense downtown (e.g., Manhattan or Cabbagetown) and never drives is either poverty-stricken or strange. People who drive drunk get behind the wheel automatically without regard for the complexity of the task of driving; it never occurs to them to use public transit. Why? In many cases, because public transit is just inconvenient enough, and car ownership not so terribly expensive, that their lives are built around their cars and they can't imagine not using them for any kind of journey.