Environment Hong Kong 2006 Chapter 1: IntroductionChapter 2: Cross-boundary and International Co-operationChapter 3: Community AwarenessChapter 4: Customer Service and PartnershipChapter 5: Environmental Assessment and Planning
Chapter 6: AirChapter 7: NoiseChapter 8: WasteChapter 9: WaterChapter 10: ConservationChapter 11: Environmental Compliance
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Chapter 7 Noise

To prevent, minimise and resolve environmental noise problems through intervention in the planning process, implementation of noise abatement measures and enforcement of the Noise Control Ordinance.
Highlights in 2005
  • Compiled a package of five strategies for dealing with traffic noise.

  • Presented a 3-D computerised noise map at a public consultation for the first time.

  • Commenced installation of a noise barrier at Cheung Pei Shan Road under the retrofitting programme, with completion expected in 2008.

  • Implemented a traffic management scheme to ban buses from using Texaco Road Flyover during night-time.

  • Protected the community along Ma On Shan Rail from railway noise through prevention at the planning stage and negotiations with the operator.

    Traffic noise can be effectively screened off by barriers.

One million people in Hong Kong are affected by excessive traffic noise, a figure that is clearly unacceptable. Yet consider this: an additional 950 000 people would be exposed to the roar of traffic if the Environmental Protection Department (EPD) was not acting to protect them through planning, prevention and mitigation. Several billion dollars have been spent on noise reduction, new laws have been introduced and new programmes implemented. The Government has worked hard to address traffic and other noise pollution, but it cannot solve these problems on its own.

Hong Kong is a vibrant and densely-populated city where many people are exposed to high levels of traffic noise.

Many people in the community contribute to noise exposure in some way, whether they are bus drivers hitting the brakes hard on a quiet residential street, developers putting up a residential block next to a busy road or railway operators expanding their service. The Government can provide a framework for reducing noise, but polluters must recognise they also have a responsibility to help make noise in Hong Kong more tolerable.

The Problem of Traffic Noise

Traffic noise in Hong Kong comes from two sources, new roads and existing roads. The EPD has made good progress on the former by providing input on the alignment of new roads. If an assessment indicates traffic noise could exceed the noise limits, consideration will be given to erect road barriers. The Government has spent about $1.3 billion since 1990 on road barriers. Together with our professional input provided at the planning stage of project development, these preventive measures have protected some 690 000 people from traffic noise. Low-noise surfaces have now become a standard practice for high speed roads.

Nearby residents are protected against traffic noise from West Kowloon Highway through a landscape buffer and noise barriers. Most existing roads have technical constraints that leave virtually no room for retrofitting barriers.

Existing roads, however, are more difficult. Hong Kong has limited land space. Buildings and roads sit close together, leaving little opportunity for buffer space or the building of noise barriers. Residents living next to busy roads typically are exposed to noise levels over 75 decibels throughout the day, well above what is considered excessive (70 decibels for six minutes in one hour). Long-term exposure to too much noise can affect stress levels and psychological health. The issue is therefore a priority for the EPD.

The department has endeavoured over the years to tighten controls at source -- from vehicles -- and where possible install barriers and low-noise surfaces on existing roads. In 2005 we packaged our efforts together and identified future directions to give the community a more comprehensive understanding of our strategies, and the public's responsibilities in helping to make them work.

Strategies for Traffic Noise Control

The EPD's first strategy in controlling traffic noise is prevention through planning and the environmental impact assessment process. The success of these efforts is described above, but there is always room for improvement. Currently we are reviewing the noise practice note on the design, development and redevelopment of residential buildings. The aim would be to help developers take greater account of road noise in their plans.

A barrier extending from the podium of a residential development protects residents from traffic noise.

The second strategy is to control noise from individual vehicles through legislation. Our vehicle noise emission standards follow the European Union and Japan, requiring newly registered vehicles to meet strict noise standards. However, even the best of these vehicles will deteriorate over time and their noise levels will increase. The problem is often the result of poor maintenance and, in some cases, tampering. The EPD therefore is exploring with the Transport Department whether noise maintenance should be a part of the annual licensing process for vehicles.

Our most difficult work is addressed through our third strategy, dealing with existing roads. We have three options: retrofit barriers or enclosures, apply low-noise surfaces to the roads or introduce traffic management measures. An abatement programme to resurface suitable road sections over the territory provided noise relief to some 50 000 people upon its completion in 1999. Further programmes for retrofitting barriers or enclosures and applying low-noise surfaces are currently underway and will protect 210 000 residents over the next 10 years. Unfortunately, these two measures are applicable to only a fraction of noisy roads due to various technical constraints.

Some 30 roads are suitable for retrofitting barriers, an expensive, time-consuming measure that started being implemented in 2004. Another 72 local roads are suitable for a low-noise surface, where work has also begun. That leaves about 550 excessively noisy roads with no technical solutions. Traffic management is the only option but it is also problematic. A pilot programme in 2003 met with opposition from the transport trade. Consequently, we have only been able to implement one traffic management scheme. From July 2005, buses have been banned from the Texaco Road Flyover from mid-night to 6am. We are continuing to explore how to make traffic management a more workable solution, but this will require greater co-operation from the trade and the community.


The EPD endeavours to protect the community from railway noise through legal standards and negotiations with railway companies. A recent case, the Kowloon Canton Railway Corporation's (KCRC) Ma On Shan Rail, demonstrated that these efforts can contain noise and build the capacity of rail operators.

The KCRC was asked to do all it could to contain rail noise and so it commissioned the quietest possible railway for this project. Extensive noise reducing features have been applied to the tracks and trains and underneath the passenger platforms. As a result, train noise has been reduced by 10-15 decibels, bringing it to well within the limits of the Noise Control Ordinance although not eliminating it entirely.

The Ma On Shan line was commissioned in November 2004 and in its first year received 62 complaints, all but two of which were lodged during the first six months when people were adjusting to the new rail sounds. The situation was helped by the KCRC's public education efforts, as the company sought to inform residents of the measures taken to reduce railway noise and help them better understand the noise situation in the area. The KCRC has now been invited to share its experiences with its counterparts on the Mainland.

A cross-section of the Ma On Shan Rail viaduct shows noise reducing features: rail configuration, train skirts and other noise reducing devices.

A Ma On Shan Rail train with noise-reducing skirts.

Noise barriers have been installed along the rail line and under the platforms.

Education and Partnership

This need for community support leads into our fourth strategy, public education and partnership. The EPD has been innovative in advancing public understanding of noise issues. We have developed a 3-D tool to demonstrate visually how road noise will affect a development. Viewers can zoom in on a single flat and see how that flat is affected. The tool was used in consulting the community for the first time in 2005, to a highly favourable response (see box). We also have an interactive noise education web page that informs people about the various sources of noise in Hong Kong and our programmes to deal with them.

Good driving habits help reduce traffic noise.

Education also requires us to raise awareness among operators. We are developing "Practice Guides" that encourage operators to take responsibility for reducing their noise. This will involve a degree of partnership in terms of supporting noise producers and understanding their constraints. Bus companies, for instance, could be asked to train their drivers to avoid heavy, noisy braking in quiet residential areas. Heavy vehicle operators could be asked to maintain their vehicles better, as rattling loose parts can be a source of irritating noise. Moreover, we are investigating the possibility of asking developers to disclose more information about noise in new residential developments.

Partnership is also an element in our fifth strategy, research and development. This is a new field in our efforts to control noise. The EPD is looking to academics and local professionals to help devise home-grown technological solutions for noise. Our initial focus is on low-noise surfaces, which currently have to be imported.

The EPD has done well to maintain the number of people exposed to excessive traffic noise to one million these past 15 years, given population growth, vehicle growth and the creation of new developments. The future, however, is less certain. By 2016 the population exposed to excessive traffic noise would be substantially increased as compared to the situation in 1997, if no further measures are in place. Hong Kong needs individual vehicle owners, bus drivers, developers and others to accept responsibility for the noise problems they create. The EPD's package of five strategies provides a framework for promoting responsible behaviour and public understanding of our efforts as we try to reduce the traffic noise pressures suffered by one in seven Hong Kong residents.


The EPD has developed a 3-D computerised model that lets people fly, walk and drive through selected sites. This tool was used in the public consultation process for the first time in October 2005. The case concerned the retrofitting of a noise barrier on Tseung Kwan O Road. Kwun Tong District Councillors were presented with a 3-D computer model that showed which flats would benefit from the barrier and how much their noise would be reduced. The model enabled councillors to instantly understand the impact of the project and facilitated discussion. In the past we would have had to rely on two-dimensional drawings and technical explanations, neither of which promote public understanding.

The 3-D model's use in noise control will be refined further with the addition of an audio clip so people can hear noise levels before and after mitigation measures are in place. The Department of Geography and Resource Management of the Chinese University of Hong Kong is developing the audio effect, which will be ready in early 2006. This technology has much potential as a public engagement tool, not just for the EPD but for other government departments and the private sector.


A digital 3-D computerised model, presented at the Kwun Tong District Council, compares noise exposure before (top) and after (bottom) the provision of noise barriers.

Noise Abatement Programmes Introduced Against the Growth in Population and Vehicles in Hong Kong

Despite the growth in population and vehicles, the EPD has been able to contain the population exposed to excessive traffic noise to around one million, the same as 1990.


  • Formulate a comprehensive plan to deal with road traffic noise through five strategies.

  • Continue to promote wider application of the 3-D noise assessment tool and incorporate an audio clip function, as part of the continuous public engagement process.

  • Continue to implement practicable engineering measures to redress traffic noise from existing roads, including barriers and low noise road surfacing.

  • Continue the effort to address various environmental noise problems in Hong Kong.

| Road Map for Noise Control | Resource Materials |