Local authorities are keen to involve the general public in local air pollution assessment strategies. However, in terms of empirical research there have been few attempts to investigate perceptions of traffic-related air pollution. Most of the research on general perceptions of air pollution has focused on a peripheral, descriptive overview, in many ways neglecting the processes that are rooted in perception formation. A common theme in previous research on perceptions of air pollution is that individuals have varying degrees of awareness and concerns about issues. The factors that guide the formation of these perceptions have not yet been determined, however. Thus, despite increasing concerns about the effects of air pollution on the environment and on public health, the psychological sciences have struggled to gain a comprehensive understanding as to how and why people perceive the air they breathe as they do.