Financial implications could make government think twice about noise

Friday, December 05, 2008

Chairman of the UK Noise Association John Stewart voices concern over noise pollution and the apparent lack of urgency from government to take effective measures to tackle it

We live in a very noisy world. According to MORI, half a million Britons move house each year because of noise.¹ The top three sources of noise are road traffic, aircraft and neighbours.

The figures are huge. Yet noise is not a priority for government. Defra, the department responsible for noise policy, is virtually silent on the matter. Its voice across government is muted. Recent legislation and initiatives from other government departments have ignored or downplayed noise: there is nothing about noise reduction in the blueprint for the eco-towns, for example; and the Department for Transport seemingly rode roughshod over Defra with its huge programme of airport expansion.

Defra has recently produced noise maps, as required by the European Union. These maps cover conurbations of 250,000 people or more plus the busiest roads, airports and railways. It is now required to draw up action plans for the noisiest areas. But the action plans are expected to have little impact as the EU legislation permits a whole number of reasons – such as excessive cost – as to why they need not be implemented. Until the government commits itself to taking noise seriously, little is expected to happen.

It is all very frustrating because there is much that could be done to reduce noise, particularly traffic noise. Some measures would be popular; others would arouse some controversy. We look at them in turn but first consider the question of the vehicles themselves.

Road traffic noise
Vehicle noise is created by a combination of rolling noise (arising from the tyres interacting with the road) and propulsion noise (comprising engine noise, exhaust systems, transmissions and brakes). As a rule of thumb, tyre-road interaction is the main cause of noise above 55kph for most cars, with engine noise predominating at lower speeds. Over the last 20 or so years, individual vehicles have become quieter, almost entirely as a result of reductions in engine noise. Tyre noise has not decreased much. The EU is currently revising its Tyre Noise Directive. There is strong pressure for it to include tougher standards for tyres, which could reduce average car noise by as much as 5.5 decibels.

There are popular, 'do-able' measures that would cut traffic noise:
• Quieter road surfaces (notably porous asphalt) can reduce noise by 4-8 decibels – the equivalent of almost halving the volume of traffic. Stone mastic asphalt, a surface more commonly used where roads may be dug up for utilities, can cut noise by 2-3 decibels.
• Good acoustic barriers can reduce average noise levels by 5-15 decibels. But, of course, the number of locations where acoustic barriers can be used is limited.
• Vegetation, if high, wide and dense enough, can cut traffic noise. A 200ft width of dense vegetation can reduce noise by 10 decibels, but, again, the number of places where this is realistic is limited.

More controversial measures to cut traffic noise would include:
• Lower speed limits can make a difference, although they don't always reduce noise levels. For example, there have been instances where badly-installed traffic-calming measures have caused more noise complaints than the traffic they slowed down. But speed is a factor in traffic noise and, at the very least, the impact on noise should be factored in when appropriate speed limits are being considered.
• Traffic volumes affect noise. 200 vehicles passing in one hour can be half as loud as 2,000 vehicles. In recent years, local authorities have made significant progress in cutting traffic volumes on many 'residential' roads by installing traffic-calming and traffic management measures aimed at restricting through traffic. This has improved the quality of life in these areas, but often at the expense of people living on the adjacent main roads. In most urban areas, and with the exception of rat runs, traffic noise is concentrated on main roads and distributor roads. The situation in rural areas is different. Over the past decade traffic levels have risen most rapidly in rural areas, resulting in traffic noise becoming worse in many villages. Until traffic reduction features on the government's agenda, it is likely that any improvement in the noise from individual vehicles will be undone by the increase in the number of cars and lorries on the roads.

Aircraft noise
Aircraft noise will prove more difficult to tackle. Individual aircraft are considerably quieter than they were 30 years ago. But that has been offset by the huge increase in the number of planes in the skies. And there is no prospect of a step change in the noise from individual planes over the next 30 years. This means that, if the government continues with its plans to treble the number of passengers using UK airports by 2030, overall noise levels from aircraft will increase still further. Aircraft noise will also spread to new areas as more airspace will be required to cope with the increase in aircraft. This summer National Air Traffic Control has been consulting on plans to increase airspace in South East England. The graph below demonstrates that, when people are exposed to aircraft, the annoyance level rises much more quickly than for rail or road noise.

It is difficult to see how aircraft noise can be brought down to more manageable levels without a reduction in the number of planes using UK airports. Given the political will, this is not an impossible task. It requires reducing short haul flights by progressively eliminating the tax breaks they enjoy and investing in affordable, fast rail lines. The experience of countries such as France and Spain, which have invested heavily in rail, shows that a switch from short haul flights will take place.

Underground noise
Perhaps the best example of how blasé the authorities have become about noise comes from London Underground. Some level of noise is always likely to be a by-product of air and car travel, but what has happened in recent years on London's underground system is that totally avoidable noises have been introduced almost as a matter of policy.

Following persistent complaints from the public, the UK Noise Association carried out a survey of noise on London Underground in 2007.² It found that, while people have lived with the high background noises on the underground for decades with little complaint, it is the huge increase in recent years in the frequency and loudness of the announcements – both on the platforms and in the trains – that have brought a deluge of complaints. Over 80% of people surveyed felt that either there were too many announcements (more than 50% of people) or that they were too loud (almost 30%). The survey found that the decibel level of the announcements on Piccadilly Line trains at times exceeded that of a jet landing at Heathrow. (Since the publication of the report, the levels have been reduced). The same is true of the platform announcements at Bank Underground Station.

Under the American Managing Director of the Underground, Tim O'Toole, this policy of loud, frequent announcements has been introduced in order to keep passengers informed about what is happening. But the UK Noise Association survey revealed Mr O'Toole to be out of touch with his passengers. The announcements are also way in excess of what is required by the regulations to assist blind and partially-sighted people.

Conclusion
Later this year the World Health Organisation is expected to publish evidence showing that excessive noise is not just annoying but it also contributes to thousands of heart attacks and deaths across Europe, costing member states billions of pounds each year. Perhaps the financial bottom line will prompt the UK government to at last break its silence about noise and begin to take effective measures to tackle it.

1 Ipos MORI Poll, 2006, commissioned by NSCA
2 Mind the (Gap) Noise, 2007, UK Noise Association