The interdisciplinary nature of this research explores the relationship between transport and urban air quality, and public responses to air pollution. Using Geographical Information Systems (GIS), perceptions of air pollution dispersion were compared with monitored and modelled air pollution data in order to detect and identify disparities. The findings demonstrate that public estimates of the causes, consequences of air pollution are not unlike scientific accounts, thus providing the “missing links” in existing research. This has major theoretical implications for risk research, bridging what we researchers perceive to be the widening “knowledge-gap” or “gulf of understanding” between experts and the public. Importance is also placed on the ways in which scientific knowledge is produced and mediated in the public realm, and the ways in which the public use this knowledge in order to shape their own understandings of their environment. This paper discusses ways in which the findings can be applied to heighten policy makers’ – particularly local authorities’ – awareness of risk communication, since the research provides valuable insight into how scientific information should be communicated to the public. Importantly, this paper will also discuss ways in which the public may share their knowledge with members of the scientific community and policy makers. The aim of this paper is to establish the significance of incorporating lay knowledge in developing strategies for the provision of local air quality information. Although air pollution specialists have attempted to put in place a “comprehensive” system of public information on air pollution in the UK (Maynard and Coster, 1999), research has suggested that public evaluations about the subject are poorly understood and under-developed (Hedges, 1993; Hedges, 1999, Jenkins 2000). In order to address this ‘deficit’ in public understandings, an interdisciplinary methodology was developed so as to provide a detailed, integrative comparison of scientific and lay evaluations of traffic-generated air pollution (Kelay, Uzzell, Gatersleben, Hughes, Hellawell, 2001). Using Geographical Information Systems (GIS), perceptions of air pollution dispersion were compared with monitored and modelled air pollution data in order to detect and identify disparities. The findings demonstrated that public estimates of the causes, consequences and severity of air pollution were very similar to scientific accounts. However, unlike scientific knowledge, lay understandings were based on knowledge of the local environment. These results have major theoretical implications for risk research, since they demonstrate similarities and differences between lay and expert knowledge, therefore bridging what we researchers have perceived to be the widening “knowledge-gap” or “gulf of understanding” between experts and the public (Slovic, Fischoff and Lichtenstein, 1985; Weening and Midden, 1997). This paper will discuss the implications of these findings. Firstly, the paper will discuss ways in which the public may share their local knowledge with members of the scientific community and policy makers through the use of participatory mapping exercises, which can be represented visually using GIS. Secondly, implications will be discussed in terms of heightening policy makers’ – particularly local authorities’ – awareness of risk communication, most notably with regards to the provision of air quality information. Although previous research has suggested a more “localised” focus for engaging the public and providing air quality information, they have failed to elaborate on the means to do so (Bickerstaff and Walker, 1999; Bush, Moffatt and Dunn, 2001). In response to these omissions in previous research, this paper will provide valuable insight into how scientific information should be communicated to the public through the use of local symbols and imagery.