Air Quality Assessments - Roads and Infrastructure

The emissions from vehicles are a major contributor to urban air pollution, but are also different to those from many industrial sources in that they are distributed throughout the urban airshed, rather than at discrete locations. Of particular concern are the emissions from heavy diesel vehicles, which produce significant quantities of very fine particulate matter. Recent studies have suggested that these emissions may be potentially carcinogenic. Katestone Environmental has conducted extensive scientific reviews of these health effects.

Pollutants produced by vehicles include carbon monoxide, nitrogen dioxide, particulate matter, sulfur dioxide, lead and a range of toxic compounds in trace quantities. These have the potential to impact on air quality at the regional level (as a major contributor to photochemical smog) and at a local level, where individual residences may be adversely affected. Key parameters to be considered when assessing the air quality from roads include the effect of slope and load on vehicle emissions, and allowance for differing emission rates from various vehicle categories (such as trucks or diesel vans).

With the introduction of new Design Rules and fuel standards and changing vehicle fleet characteristics it is important to use appropriate emissions data to assess future impacts. Katestone Environmental regularly uses the latest emissions studies and methodologies, and has developed in-house software to facilitate accurate assessments.

Traffic assessments.

Katestone Environmental has worked extensively in predicting urban air quality effects due to vehicle emissions. These assessments have included evaluation of pollutants emitted from major urban roads and regional freeways, the measurement and prediction of dust emissions due to unsealed roads, the design of portal vents for vehicle tunnels and the development of criteria to be used to site facilities for sensitive groups (such as child-care centres and schools) close to roads. Local Governments are increasingly requiring detailed assessment of all potential air quality impacts in relation to new proposals. Katestone Environmental has had extensive involvement in an expert witness role for the siting of freeway tunnel ventilation stacks and performing detailed air quality studies for major roads.

Katestone Environmental can undertake modelling with widely-accepted motor vehicle computer dispersion models for local impact assessments, but has the expertise to undertake large regional modelling projects using alternative models and detailed emission inventories. Experience with Brisbane emission inventory studies and the development of the Gladstone Airshed model, Southeast Queensland ozone forecasting software and in-house plume photochemistry models emphasises flexibility in devising new approaches to complex major assessments.