Archive / Engine brake noise

The loud ‘bark’ caused by engine brakes on heavy vehicles fitted with worn, defective or inferior mufflers is a community concern

Engine brake noise

Review of the national in-service standard for engine brake noise

In May 2012, the Commonwealth Minister for Infrastructure and Transport requested that the NTC review the model law for engine brake noise in collaboration with states and territories. The national standard for engine brake noise was approved in 2007 but no state and territory has introduced the necessary laws.

The NTC conducted the review to understand why states and territories have not yet implemented the standard and to provide advice to assist its implementation. The review found that specific technical and operational problems for enforcing the standards has resulted in no state or territory implementing the necessary laws. To address these problems, operational procedures for enforcement and testing and certification of the noise test equipment needs to be developed.

Roads and Maritime Services NSW worked with other states and the NTC to develop these operational procedures. 

The NTC is amending the national laws, through our maintenance program to adopt engine brake noise standards.


An in-service standard to manage engine brake noise was approved unanimously by transport ministers in November 2007. 

During consultation, the community broadly supported the regulation, while the trucking industry’s views ensured it is practical and only targets the small number of operators who cause excessively annoying braking noise. The Environment Protection and Heritage Council (now the National Environment Protection Council (NEPC)) also voted unanimously in favour of the proposal.

Noise from engine brakes is the greatest source of community complaint against the heavy vehicle industry. This noise problem has the potential to restrict access to roads by heavy vehicle because of demands for curfews and other restrictions from affected populations.

The NTC was asked to address the situation and undertook research to determine the feasibility of a regulatory solution to noise from engine brakes. The NTC worked with transport agencies, environment agencies and truck manufacturers to propose a solution which represents a breakthrough for the control of noise from engine brakes. Extensive research underpinned the proposal. The NTC investigated a number of ways to control this noise without introducing unfair restrictions on industry or creating a safety issue.

Transport ministers approved the proposal for an in-service standard for engine brake noise on 2 November 2007. The development of the proposal was in partnership with the Department for Transport, Energy and Infrastructure South Australia, the Roads and Traffic Authority New South Wales and VicRoads.


Last Updated: 1/7/2015