Putting people and cargo onto the rails may be one way to reduce roadway air pollution, a key goal of the EU’s rail transport policy, but doing so creates another hazard for those living close to railways – noise.
The European Commission is due to present a recast of the 2002 Environmental Noise Directive this spring aimed at producing quieter living and working environments. Recent railway legislation has also sought to accelerate modernisation of transboundary rail services and infrastructure.
With more than 400,000 older, squeakier cargo wagons crisscrossing Europe, research shows that the noise they produce poses health risks.
A new French study says long-term exposure to railway noise can disturb sleep patterns, leading to reduced concentration levels that may not even be noticed by those in earshot of train lines.
“Overall, it seems that people permanently exposed to nocturnal railway noise suffer chronic daytime sleepiness objectified by detrimental effects on attention and daytime sleepiness even though they are not necessarily aware of these deficits,” says the study in the Journal of Environmental Psychology, whose authors included researchers from the University of Strasbourg and the state railway company SNCF.
Consistent noise over the long term, the researchers said, is “detrimental daytime functioning.”
Iron and steel
Most railway noise is caused by the contact between cast iron braking blocks and steel rails. Newer trains use alloys that reduce the tension and there has been success in using composite parts to retrofit older wagons.
“That’s been a big challenge that has just been nailed,” said Matthew Ledbury, senior environment advisor for the Community of European Railway and Infrastructure Companies (CER), though he said funding for refitting old trains with quieter braking systems is “the big challenge.”
Other noise-reduction methods include noise absorbers on rails, sound barriers parallel to tracks, and improved insulation in homes along rail lines. A February study by the International Union of Railways (UIC) shows non-EU member Switzerland has been a leader in taking steps to control railway noise, followed by Germany and the Netherlands.
But retrofitting older wagons is seen is the most affordable method. Rail industry figures show that the nearly the entire stock of older freight wagons could be retrofitted with quieter braking technology for about the cost – up to €150-€200 million – spent annually on railway noise barriers.
Tests show that braking systems using composite material that can reduce braking noise levels by half, or 10 decibels, compared to the cast-iron variety. A normal human conversation is about 60 decibels.
“Retrofitting is most cost-effective if carried out during compulsory freight wagon inspection, which must be undertaken at least every six years,” said a 2007 UIC report.
Aircraft vs. trains
The Commission’s First Railway Package proposed measures to reduce infrastructure access charges to help encourage the switch to newer, quieter rail wagons. Its TEN-T transportation infrastructure package and Connecting Europe Facility also seek to encourage quieter transport. The December 2011 Airports 2030 package, meanwhile, urges airlines to phase out older, noisier airplanes.
Aircraft noise continues to be a main source of political angst, and many EU airports restrict night landings. Estimates show that a mid-range aircraft on flight approach produces 90 decibels, while a cargo train at 15 meters is slightly quieter.
But last year, researchers at the Institute of Aerospace Medicine in Cologne showed that trains may be more disruptive to humans.
“Nocturnal freight train noise exposure in Germany was associated with increased awakening probabilities exceeding those for aircraft noise and contrasting the findings of many annoyance surveys and annoyance ratings of our study. During night time a bonus for railway noise seems not appropriate,” the German researchers said.