Reducing noise

Note: Please reference the procedures and guidelines linked to on this website for the latest versions as updates will be published here from time to time.

Management of road traffic noise is an important issue as traffic growth continues. Roads and Maritime Services works to provide efficient road transport infrastructure while limiting the noise from traffic and individual vehicles.

Roads and Maritime Services' corporate commitments and principles for managing noise are outlined in our guidelines and procedures.

These documents ensure that Roads and Maritime’s activities protect community amenity and also meet the requirements of the NSW Environment Protection Authority and the Planning and Assessment Act.

There are four ways in which Roads and Maritime influences local environmental noise. These are:

Roads and Maritime also provides guidance to assist contractors and consultants in assessing noise with standard briefs and procedures.

Operation and design of roads and facilities

The NSW Road Noise Policy (RNP), produced by Office of Environment and Heritage, is managed by the Environment Protection Authority and outlines NSW criteria for different road types. Roads and Maritime guidelines relate the criteria for different road types to specific existing, new or upgraded roads.

The NSW Industrial Noise Policy (INP), also produced by the Office of Environment and Heritage and managed by the Environment Protection Authority, outlines NSW criteria for permanent off road facilities located at fixed sites.

Road projects including minor works

Roads and Maritime has a number of guidelines which assist in modelling noise, setting criteria, assessing noise and designing mitigation which meet the requirements and intent of the NSW Road Noise Policy. See the fact sheet for more information on differences between the NSW Road Noise Policy and Roads and Maritime guidelines.

The following guidelines are to be used for assessing the operational noise impact of road projects and minor works. These guidelines feature overarching principles which must be met and procedures which assist in meeting the principles.

These other Roads and Maritime publications may assist in the urban design considerations of mitigation:

Permanent off road facilities located at fixed sites are assessed under the NSW Industrial Noise Policy. Examples of these sites include but are not limited to: truck stops, bus lay overs, ventilation portals and sub-stations.

Noise Abatement Program for existing roads

Roads and Maritime Services’ Noise Abatement Program (NAP) is available to community impacted by existing roads where eligibility criteria are met.

For receivers that are eligible, feasible and reasonable noise mitigation measures are identified using the procedures in Section 7 and Section 8 of the Noise Mitigation Guideline and in accordance with the Noise Abatement Program.

New development near busy roads

New residences and buildings constructed near busy roads may be required to address noise from existing roads. Guidance was previously given in the Environment Protection Authority’s Environmental Criteria for Road Traffic Noise. On 1 January 2008 some State guidance became mandatory under Clause 102 of the Infrastructure SEPP.

The Department of Planning’s Interim Guideline for Development near Rail Corridors and Busy Roads outlines how to apply Clause 102 and gives some guidance for other situations. The key objective of the SEPP is to ensure that adjacent development achieves an appropriate acoustic amenity inside the building. Note that in addition to the SEPP acoustic assessment may also be required for noise sensitive developments under a Council’s development control plan or conditions of approval for a development application.

Guidance is also given for new development in the NSW Road Noise Policy as outlined by the existing road criteria.


Road maintenance activities may be defined as those that do not alter the existing road configuration or any pavement works within the existing road pavement footprint. They also do not have potential for an operational noise impact after completion of the works.

Roads and Maritime Services’ approach to managing noise and vibration impacts from maintenance is to apply safeguards for the work activity. The safeguards are applied through the use of Standard Mitigation measures and Additional Mitigation Measures as outlined in the Maintenance Estimator tool. These safeguards supersede Practice Note (vii) of the Environmental Noise Management Manual.

View or download the Construction and Maintenance Noise Estimator tool.


Road construction during minor works and more significant road upgrades alters the road configuration and usually the road footprint. They also have potential for an operational noise impact after completion of the works.

Roads and Maritime’s approach to managing noise impacts during road construction is detailed in the following guideline:

Construction Noise and Vibration Guideline (CNVG) (supersedes Section 5 and Practice Note (vii) of the ENMM).

This guideline provides direction on managing noise and vibration impacts from construction and maintenance activities. It either recommends use of an Estimator tool or a full quantitative assessment depending on the risk factors.

View or download the Construction and Maintenance Noise Estimator tool.

Reducing vehicle noise

Noise Emission Standards

Roads and Maritime Services strongly advocates tighter vehicle noise standards. New noise standards for light and heavy vehicles were introduced in 2003 under Australian Design Rule, ADR 83/00 and took effect from 2005.

This new noise standard means that newer cars are 3dB quieter and that newer trucks and buses are 4-7dB quieter than older standards.

The 2005 standard includes a 'signature' noise level that is recorded and unique for each vehicle model. These model specific standards will form the basis for enforcement of noise standards in the future. The signature approach is designed to minimise excessive noise caused by poorly maintained or modified exhausts.

Regulation of heavy vehicle noise

Roads and Maritime completes periodic inspection of heavy vehicles at testing stations to ensure that silencers are fitted and maintained. Heavy vehicles on Australian roads during normal operation and acceleration must meet noise requirements outlined in the Australian Design Rules.

Roads and Maritime is part of a Commonwealth process coordinated by the National Transport Commission to look at ways of reducing engine compression brake noise.

Heavy Vehicle Engine Brake Noise

Noise from heavy vehicle engine compression brakes is a significant and on-going cause of complaint for many NSW residents. Engine brakes are devices fitted to the engine of heavy vehicles to slow the vehicle down. They are often referred to as 'auxiliary braking devices' or 'secondary retarders'.

A driver switches on the engine brake and it engages on release of the acceleration pedal. Engine brakes operate by causing the engine to act as a compressor when braking. The compressed air is released in short bursts which cause the characteristic engine brake 'bark'. It is mostly the nature of this noise, rather than its volume that causes annoyance.

Engine brakes improve vehicle safety by reducing the load on service brakes on a steep descent but their use elsewhere provides little safety benefit. They can also extend the life of the vehicles service brakes and reduce maintenance costs.

Trucking is an important business. But the constant use of noisy engine brakes is hurting the industry's image.

The worst problems occur when drivers use their engine brakes unnecessarily near built up areas, especially at night when residents are trying to sleep.

What can truck operators do

You can reduce engine brake noise around residential areas by:

  • Installing a muffler that is specially designed to reduce engine brake noise
  • Ensuring that your exhaust system is in good condition
  • Turning off noisy engine brakes in built up areas.
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