NSW Road Noise Policy Review

Emeritus Professor Alan (Lex) Brown is a highly experienced researcher with significant experience in the field on road traffic noise.

He has published over 130 papers on environmental planning and acoustics. He was a member of the Systematic Review panel for the development of the World Health Organisation Environmental Noise Guidelines for the European Region, and a member of the expert advisory group for the Commonwealth Government Health publication The Health Effects of Environmental Noise.

Learn more about Professor Brown’s experience and expertise.

Professor Brown's report, “A literature update for review of the NSW Road Noise Policy against contemporary scientific standards and settings”, considered national and international material on the effects and management of road traffic noise from around 2010/2011.

It presents a narrative of research on road traffic noise and is not a peer-reviewed scientific study. The report does not provide any policy recommendations but provides the current ‘state of play’ of research in the field and addresses a range of topics, including:

• the health effects associated with road traffic noise
• evidence for using different noise metrics to measure and assess exposure to road traffic noise
• developments in road traffic noise prediction models and mapping noise exposure
• strategic and practical noise mitigation practices
• other topics, including electric vehicles and areas of emerging research.

The report is highly technical and aimed at acoustic, transport, policy and planning professionals, and may also be of interest to the wider community.

The report does not make recommendations or comment on the adequacy (or otherwise) of the RNP, but when compared to criteria adopted in other jurisdictions, as well as recommendations by the World Health Organisation, the RNP criteria remains conservative.

The EPA will review whether there is a need to update the NSW Road Noise Policy in 2030.

While the NSW Road Noise Policy (RNP) is designed to protect people from being highly annoyed by noise, it will also provide a degree of protection against other health endpoints, including the risk of chronic illness such as cardiovascular disease.

The EPA will continue to evaluate the scientific evidence and review whether to update the NSW Road Noise Policy in 2030.

Note: A chronic condition is a health condition or disease that is persistent or otherwise long-lasting in its effects or a disease that comes with time.
 

While there has been a shift to a public health focus on environmental noise, annoyance remains an important consideration. The RNP criteria is based on exposure-response studies on annoyance published prior to 2011. The report has considered studies from around 2010/2011 and concludes that the research has not identified any significant change to the research cited in the RNP that would warrant consideration of varying the RNP at this time.

The report did not find evidence that the presence of low frequencies in road traffic noise has an effect on human response not already accounted for by current equal energy (LAeq) measures.

Noise 'events', such as a sudden increase in noise, are known to disturb sleep. But there remains significant uncertainty and technical challenges on how to measure the level and number of road traffic noise events and correlate this with evidence-based research to inform any changes in the RNP.

There is no evidence of a different response to intruding traffic noise in rural areas, only a different prevalence regarding expectations of quiet.

There is no evidence to indicate that any one type of noise modelling methods is better than others or that any are deficient and should not be used.

The report provides helpful information on strategic road traffic noise management approaches, with advice on a framework to guide any policy review and development, and advice on prioritising noise mitigation strategies. 

The ‘excess response’ change effect occurs where the total difference between the before-outcome and the after-outcomes for a noise intervention (e.g. introduction of a noise barrier) is greater than the magnitude of the change in response estimated from an exposure-response function - for the given change in exposure.

There is evidence that communities that experience an increase in noise exposure are likely to experience greater annoyance than is predicted from existing exposure–response relationships, and communities that experience a decrease in exposure experience greater benefit than predicted.  

The report suggests that policy makers need to be informed of these potential change effects, particularly as situations in which noise levels increase as a result of infrastructure changes are always likely to be contentious. This evidence may be important to understand potential community response in these contexts, helpful for managing community expectations, and to inform best-practice mitigation.

NSW policies and guidelines set criteria / trigger levels externally with an assumption that a building façade (windows) provide a given level of noise attenuation. Research indicates that the NSW settings remain reasonably conservative.