The environmental hazards of transport are becoming increasingly well-known and much research is aimed at cataloguing and quantifying the harmful impacts of traffic on human health and well-being. Regrettably, research into the development of suitable stress indicators of traffic is not matched by the availability and quality of applicable environmental data. The reason for this is clearly one of cost, since even a modest amount of monitoring over a relatively small area such as a local authority for the range of air pollutants and noise (not to mention less tangible impacts such as severance or lack of visual amenity) would be beyond the budget of most local authorities. One way to overcome this problem is to use models to predict air quality and ambient noise levels from traffic counts and other land use and meteorological data. This paper demonstrates the facility of geographic information systems (GIS) to use modelled data to create surfaces (or maps) of relative pollution levels by the interpolation of point data. Traffic count data for a major arterial road in Huddersfield were used as the major input to the CALINE4 line source dispersion model and the Department of Transport's Calculation of Road Traffic Noise model. Outputs from these models were input to a GIS and interpolated into surface maps. Some verification of the surfaces was attempted using monitored data for noise levels and nitrogen dioxide concentrations from passive diffusion samplers. The analysis of other environmental impacts such as severance, road accidents and visual disamenity may also benefit from the application of GIS functionality. The creation of a reliable GIS traffic impact assessment database requires the input of a lot of costly data and end user effort, but this is justified by the improved information which is generated and which can be used to inform local decision making on environmental and traffic issues.
Abstract