aerial image of a busy intersection with cars, buildings, and trees

Mastering mobility: noise pollution

According to the European Environment Agency (EEA), one in five people living in the European Union are exposed to noise pollution and long-term noise levels that are considered harmful to their health. From sleep disturbances to cardiovascular issues, noise has also been shown to even have impacts on children’s ability to learn. These negative impacts affecting roughly 100 million residents are due to traffic noise. This translates to one million healthy years lost per year to illness, disability or early death due to road, rail and air transport-related noise.

Given that the European Environment Bureau lists noise pollution as one of the most significant threats to public health, after air pollution, there are numerous action plans in place. The reduction of noise is currently a key objective under the EU’s Zero Pollution Plan for 2050, which aims to reduce the share of people chronically disturbed by transport noise by 30% by 2030. And the Environmental Noise Directive is the main EU law focused on identifying and addressing noise pollution. So, what kinds of interventions can be employed to minimise noise pollution?

Mapping the problem

Solutions to eliminate noise pollution are varied in their approach. Some innovations aim to muffle, dampen or mute sounds; while others focus on eliminating noise from the outset. But before eliminating noise pollution, it is necessary to find where it occurs.

The European Environment Agency’s aptly named NOISE project, an acronym for Noise Observation and Information Service for Europe, has mapped noise levels stemming from road, rail, air and industry. By highlighting zones that require immediate, mid-term and long-term mitigations; the right innovations can be found for each situation and cities and citizens alike can be empowered with knowledge.

Innovations in noise dampening

Since the 1960s, ‘noise barriers’ (also referred to as sound barriers, soundwalls or acoustical barriers) have been used to mitigate the sounds of high-intensity traffic, commonly in the form of large walls or barriers erected next to highways, to dampen and refract the sounds of road traffic for people living or working nearby. While traditionally noise barriers have consisted of these wall-like structures, there are innovations taking place that rethink what a noise barrier could look like. These innovations are highly anticipated, as the traditional noise barrier wall has long been criticised for its visual drawbacks.

The EU-funded WHISSPER project promotes technology by Dutch company 4Silence, and offers visually unobtrusive solutions that harnesses the power of diffraction. The company has prototyped three different solutions that bend traffic noise in an upward direction, to reduce horizontal noise. Their proprietary WHISstone is placed next to the road at ground level, reduces traffic noise by 2.5 decibels, equal to silent asphalt and at a fraction of the cost. Similarly, their WHISwall, only a metre in height, accomplishes the same noise reduction as a traditional three metre noise barrier. And their WHIStop, covers barriered zones and accomplishes the equivalent of an additional two metres of barrier height. This solution is suitable for rail in particular.

Additionally, the European Union’s Horizon Europe, an ambitious research and innovation framework, is also funding research into silent roads, eliminating the need for sound dampening in the first place. The Silent Rubber Pave project utilises RARx technology, a new way of making asphalt roads by utilising end-of-life tire rubber for a circular solution that produces five decibels less sound than traditional road paving.

Low tech but high reward

Less technologically heavy innovations for sound elimination are also gaining traction. For example, ‘green tracks’ in which grass, or other suitable plants, are planted underneath and surrounding tram or railway tracks, are an arguably ‘low tech’ option for reducing noise pollution from rail transport. According to the Journal of the Acoustical Society of America green tracks help to reduce this noise by up to three decibels and offer several additional positive knock-on effects. Firstly, depending on the construction process, the implementation of green tracks can decrease the demand for concrete, which is a heavy carbon dioxide emitter. The greenery can also collect rainwater, serve as habitat for insects and food for bees, reduce urban temperatures and capture fine particulate matter.

Additionally, policy and planning interventions like reduced speed zones, low emissions zones that only admit micromobility or electric vehicles, and increased pedestrianised spaces all work towards eliminating noise pollution. Lower speeds have been shown to produce less noise, while low emissions zones encourage alternative transport modes that are often quieter than traditional cars. For example, the city of Zurich, Switzerland has reduced the speed limit from 50 kilometres per hour to 30 on parts of its street network, for an average noise abatement between three and five decibels. The city anticipates that the project will positively benefit 48,000 residents during the day and 95,000 residents will benefit during the night. 

A quieter Europe

Thus, the larger transition from car-centric transport to sustainable urban mobility is likely to have positive effects on reducing noise pollution. By encouraging active mobility, and prioritising the return of public space to citizens, road noise from individual cars will be drastically reduced.

While noise pollution plagues citizens around the world, the combination of innovative solutions and policy interventions currently being implemented throughout Europe inspires hope for a quieter future.

Want to know more?

  • Take EIT Urban Mobility’s free online course Tackling noise pollution in cities
  • Or learn about the Quiet Brussels plan with Urban Mobility Explained’s video (subtitles available):