Reducing road traffic noise

Note: Please check the procedures and guidelines linked 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. Transport for NSW works to provide efficient road transport infrastructure while limiting the noise from traffic and individual vehicles.

Transport for NSW's corporate commitments and principles for managing road traffic noise are outlined in our guidelines and procedures.

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

There are five ways in which road activities influence local environmental noise. These are:

Transport for NSW also provides guidance to assist contractors and consultants in assessing road traffic noise with standard briefs and procedures.

Operation and design of roads and facilities

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

The NSW Noise Policy for industry (NPfi), 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

Transport for NSW 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 Appendix B in the Road Noise Criteria Guideline for more information on differences between the NSW Road Noise Policy and Transport for NSW 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.

NOTE: Some projects may still require the legacy Roads and Maritime Environment Noise Management Manual (ENMM). Please contact a Transport for NSW noise specialist as required for this document.

These other Transport publications may assist in the urban design considerations of mitigation:

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

Noise Abatement Program for existing roads

The Transport for NSW 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 Road 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.

Transport’s 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.

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.

Transport's approach to managing noise impacts during road construction is detailed in the following guideline:

Construction Noise and Vibration Guideline  (applicable for Roads and Maritime projects/works)

This guideline provides direction on managing noise and vibration impacts from construction and maintenance activities related to roads and maritime work. 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

Transport for NSW 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.

Heavy vehicle noise

Transport for NSW completes periodic inspection of heavy vehicles at testing stations to ensure that silencers are fitted and maintained. Inspections are also carried out during yearly vehicles registration. Heavy vehicles on Australian roads during normal operation and acceleration must meet noise requirements outlined in the Australian Design Rules.

Heavy Vehicle Engine Compression Brake Noise

Noise from heavy vehicle engine compression brakes is a source of complaint for some NSW residents. This noise source has however been progressively reducing over the years partly due to quieter technology on the newer generation of heavy vehicles and natural fleet renewal over time.

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, such as by reducing the load on service brakes on a steep descent. 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  hurts 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
  • consider the community by turning off or not unnecessarily using noisy engine brakes in built up areas.
Share this page: