Indeed, the "appropriate" role of the automobile is the question facing transportation planners and decision-makers. On one hand, the automobile has provided unprecedented mobility to the majority of North Americans and is by far and away the dominant means of social and economic interaction throughout North America. At the same time, automobile use generates a wide variety of adverse impacts, including:
- congestion (and associated stress and productivity losses);
- pollution (smog, particulates, other health-related hazards);
- greenhouse gas emissions (and their contribution to global warming/climate change);
- accidents (fatalities; personal injuries; property damage);
- "excessive" consumption of land (discussed below).
Historically, we have tolerated these adverse impacts for a variety of reasons, but mainly because:
- they were perceived to be small relative to the benefits obtained (for example, congestion historically was perceived as being within tolerable limits);
- the impacts were not well understood (for example, our awareness of the true costs of pollution and greenhouse gas emissions has grown over the years);
- we have more or less mindlessly chosen to ignore adverse impacts (for example, the death toll attributed to automobile accidents).4
The drawbacks of overdependence on the automobile, however, are becoming increasingly apparent and increasingly onerous as our urbanized areas have grown in size and population, to the point at which most informed observers of urban trends seriously question the environmental, social, and economic sustainability of our current urban form and its associated automobile-based transportation system. Indeed, the existence and mandate of the Central Ontario Smart Growth Panel is in no small part motivated by this very issue.