Reducing road traffic noise
Management of road traffic noise is an important issue as traffic growth continues. Transport for NSW works to provide efficient road transport infrastructure while minimising noise from traffic.
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 meet the requirements of the NSW Environment Protection Authority and the Planning and Assessment Act.
Transport for NSW also provides guidance to assist contractors and consultants in assessing road traffic noise with standard briefs and procedures.
There are five ways in which road activities influence local environmental noise. These are:
- Operation and design of roads and facilities
- Reducing vehicle noise
- Heavy vehicle noise
Operation and design of roads and facilities
The NSW Road Noise Policy (RNP), prepared by Department of Environment, Climate Change and Water is a cabinet endorsed document administered by the Environment Protection Authority. It presents the NSW Government’s approach to the assessment of road traffic noise. The document presents noise criteria for noise sensitive receivers near different road categories and requires a feasible and reasonable approach to noise mitigation on new projects. Transport for NSW guidelines support the RNP and outline how criteria are applied and the feasible and reasonable approach are implemented on its projects.
The NSW Noise Policy for industry (PDF, 1.41 MB) (NPfI), also administered by the EPA, outlines NSW government criteria and assessment methodology for noise from fixed sites and facilities. It is utilised for the assessment road infrastructure facilities such as truck stops, bus lay overs, ventilation portals and sub-stations, etc.
Road projects including minor works
Transport for NSW has several 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 (PDF, 4.75 MB) 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.
- Route Option Assessment (contact a Transport for NSW Noise Specialist)
- Road Noise Model Validation Guideline (RNMVG) (PDF, 1.06 MB)
- Road Noise Criteria Guideline (RNCG) (PDF, 4.75 MB)
- Application Notes – Road Noise Criteria Guideline (PDF, 10.38 MB)
- Road Noise Mitigation Guideline (RNMG) (PDF, 2.91 MB)
Note: Some projects may still require the legacy Roads and Maritime Environment Noise Management Manual (ENMM). Please contact a Transport for NSW Noise Specialist 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 with reference to the NSW Noise Policy for industry. 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 noise sensitive receptors impacted by existing roads where certain eligibility criteria, including specific noise level thresholds, are met.
For receivers that are eligible, feasible and reasonable noise mitigation measures are identified using the procedures in Section 6 and Section 7 of the Road Noise Mitigation Guideline and in accordance with the Noise Abatement Program.
New development near busy roads
New residences and other noise sensitive buildings planned for construction near existing busy roads may be required to address noise from the roads. Commencing from 1 January 2008, State requirements, including specific internal noise limits, were first introduced for noise sensitive developments near existing busy roads and became mandatory under Clause 102 of the now superseded Infrastructure State Environmental Planning Policy (SEPP). Clause 2.120 of the current Transport and Infrastructure SEPP (2021) (T&I SEPP) outlines the current requirements for noise-sensitive developments.
The Department of Planning and Environment’s Interim Guideline for Development near Rail Corridors and Busy Roads (PDF, 4.42 MB) provides additional practical guidance in support of the SEPP. This includes planning guidance to minimise noise, for example placement of sensitive buildings, building orientation, location of sensitive rooms and occupancies, etc. The key objective of the SEPP is to ensure that noise sensitive developments adjacent to an existing road achieve an appropriate acoustic amenity inside the building. Note that in addition to the SEPP, an 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 for new development is also provided 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 increased 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 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.
The EPA’s Interim Construction Noise Guideline (ICNG) presents high level guidance to the assessment and mitigation of construction noise. The guideline considers the temporary, inherently noisy and difficult to mitigate nature of construction activities and adopts a feasible and reasonable approach to the mitigation of construction noise.
Transport's approach to managing noise impacts during road construction is detailed in the following guideline: Construction Noise and Vibration Guideline (Roads) (PDF, 1.46 MB)
This guideline provides guidance on the feasible and reasonable approach to managing noise and vibration impacts from construction and maintenance activities related to road works, as required under the ICNG. It either recommends use of the Estimator tool or a full quantitative assessment depending on the risk factors.
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 and emission systems are fitted and maintained. Inspections are also carried out during yearly or half yearly vehicles registration. Heavy vehicles on Australian public roads are designed to meet noise requirements outlined in the Australian Design Rules.
Heavy Vehicle Engine Compression Brake Noise
Noise from heavy vehicle engine compression brakes has been 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 fleet renewal that occurs with 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. They are not illegal on NSW roads due to the safety aspect in addition to other benefits.
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.