Turn down the noise - softening the impact of excess transport noise

Clearly, transport noise's long-term impacts fall a long way short of the apocalyptic projections for unabated global warming. Equally clearly, however, they're not limited to annoyance. As a growing body of research reveals, transport noise can cause sleep disturbance, cardiovascular disease, elevated hormone levels, psychological problems and even premature death; studies on children have identified cognitive impairment, worsened behaviour and diminished quality of life.

The serious effects of transport noise have been recognised since the 1970s. For a long time, however, they received relatively little attention while the public focused instead on transport's air pollution impact. Little effort went to collecting harmonised transport noise data in Europe, which in turn weakened the case for an effective response.

The situation is at last changing. Following the adoption of the Environmental Noise Directive in 2002, the EEA's recent TERM 2008 report Transports at a crossroads is the first to contain an assessment of EU-wide noise data. Its findings give cause for concern. Fifty-five per cent of those living in urban areas with more than 250 000 inhabitants in the EU-27 — almost 67 million people — endure daily road noise levels above the lower EU benchmark (55 Lden) for excess exposure.

Cutting noise takes more than cutting traffic

If the extent of the problem is pretty clear, the appropriate policy response is perhaps less so. At first glance, the obvious remedy would be measures that reduce transport volumes. These would address the source of noise pollution but also provide additional gains such as cutting transport's greenhouse gas emissions and air pollution. By contrast, other responses, such as building new roads further from homes, may offer few ancillary benefits or even exacerbate other environmental problems.

Cutting traffic will clearly be crucial in addressing many of transport's environmental impacts. As a strategy to reduce noise volumes, however, it has limitations. Reducing car traffic on roads with a high proportion of lorries and busses, for instance, has little impact on the overall traffic noise since car noise is masked by the heaviest vehicles. To be effective, therefore, the noisiest vehicles have to be targeted first. But even on roads where vehicles produce roughly the same amount of noise (e.g. mostly cars), a traffic reduction of at least 40 % would be needed to start perceiving reduced noise.

Policymakers therefore need to identify complementary, cost-effective measures that primarily reduce noise at source (while bearing in mind the potential to mitigate or exacerbate transport's other environmental impacts). Fortunately, many potential measures are already available, including:

• technological improvements to vehicles and aircraft aerodynamics and components, including low noise tyres, train wheels, brake-blocks, and landing gears;
• improvements to infrastructure, such as low noise road surfaces and rail tracks;
• urban planning that limits encroachment close to busy roads, railways or airports, and rules on the location, layout and acoustic quality of buildings;
• traffic management techniques, such as traffic calming, controlling the speed of road vehicles, and  low noise operational procedures for aircraft;
• restricting access for the noisiest vehicles and aircraft (e.g. at night);
• noise barriers and improved soundproofing of dwellings (although only as a last resort because these measures are rarely cost-effective).

Integrated policy packages are needed

Both market-based and regulatory measures can be used to give transport manufacturers, planners, consumers and service providers the right incentives to adopt new technologies and practices. These could be based on vehicle noise standards or product labelling (e.g. tax rebates based upon tyres noise label). Fines or subsidies can also encourage noise reduction, while helping victims of noise pollution take steps to protect themselves.

Experience in the air transport sector illustrates the idea. Life under a flight path can be very noisy and looks likely to get noisier if air travel continues to grow. Happily for those living close to France's ten largest airports, help is at hand. ACNUSA, an independent body established in 1999, charges airlines according to aircraft noise levels and time of departure and fines airlines that don't comply with noise restrictions.

These fees mean that airlines and their customers are compelled to bear some of the social costs of air travel, which are seldom reflected in ticket prices. By reducing demand for tickets, this helps ensure that flight volumes correctly balance society's desire for air travel against its wish to avoid noise and other forms of pollution. The varying fees also sharpen incentives to fly at less disruptive times of day and to adopt technologies and practices that minimise noise. Better still, the revenues of the scheme (EUR 20–55 million a year) are used to subsidise soundproofing the most exposed dwellings, with between three and eight thousands dwellings upgraded every year.

As experience in London and elsewhere has demonstrated, the technology now exists to charge road users according to vehicle type and time of day, with proceeds supporting, for example, expanded public transport systems. As recognition of noise pollution's impact grows, such technology should facilitate the introduction of creative policies like France's airport charging scheme across the entire transport sector.