11.07.2025
Traffic noise doesn't need an invitation – it's enough for someone to drive, and it comes. Road and aircraft noise, city traffic, tram triangle – all of them are constantly coming in through the window. When building new roads, for example, the Rail Baltica international high-speed railway, potential noise is first modelled so that the railway and facilities can be designed to cause as little disturbance as possible – for example, by building noise barriers if necessary, and planning landscaping in advance.
But how do you measure sound that doesn't exist yet? Noise models help engineers, planners and environmental specialists assess where and with what solution future traffic noise needs to be mitigated. This is the same for Rail Baltica and new roads. And since no place in Estonia is completely untouched by traffic noise, this is a question that sooner or later concerns each of us.
But what is “train noise” anyway?
“The main source of noise is the contact between the wheels and the rails – metal meets metal, that’s where the main sound is made,” says Silver Lind, CEO and senior expert at ELLE, a company that offers a wide range of environmental consulting services both in Estonia and abroad. Indeed, if the rails are properly sanded and the joints smooth, a modern electric train is much quieter than most of us would think – especially when compared to what we remember from the old diesel trains.
"In the case of Rail Baltica, the most modern electric trains are planned to run on it. Their impact on noise levels may be even smaller than, for example, on some main roads, where the flow of cars is constant and sometimes even more disturbing," confirms Lind.
Sound from the future
Rail Baltica will be completed by 2030. However, it is possible to estimate quite accurately what kind of sound future trains will make and how far it will travel. How is this modeled?
“The sound is modeled using internationally recognized noise models that are based on previous measurements and standards,” explains Lind. This means that the model “knows” different types of trains and can estimate how loud one or another train is at different speeds, in different curves or when braking. If it is a new train type that does not yet have measured data, it can be added manually – based on the manufacturer’s technical data.
The result is a noise map: it shows in which areas sound levels may exceed the standard levels. It is based on this data that decisions are made as to where a noise barrier should be installed, and where landscaping or an earthen embankment may suffice.
“The modeled situation generally estimates reality more harshly – this is part of the precautionary principle,” says Lind. “In real life, train noise is generally quieter than shown in the model, because the noise model does not take into account, for example, existing tall vegetation, which actually absorbs sound.”
What is louder: a road, a railroad, or a lawnmower?
The question of whether a train is louder than a lawnmower is not stupid – it helps to make sense of the invisible. The traffic noise in the center of Tallinn is incessant – it is simply there all the time. The train, on the other hand, comes and goes.
“A nearby train might make a louder sound for a moment, but it’s only for a short while and then it’s quiet again,” explains Lind. The road, on the other hand, is never quiet. There’s a constant flow, with the occasional roar of a truck or a noisy motorbike.
Technology also comes into play with Rail Baltica trains. These passenger trains are electric and new, unlike the trains produced in the last century. They also don't run every two minutes. "The noise level is also affected by the traffic frequency - in the case of Rail Baltica, the load is not planned to be such that there is something to hear all the time," says Lind.
But how far can the sound of a train be heard? It depends on everything: the terrain, the distance, the existing buildings or forests. "If a person lives in the middle of a field and there are no other objects nearby that make noise, then the train can really be heard from a distance. But at a distance of hundreds of meters, the sound is usually no longer disturbing," confirms Lind.
Noise barriers or trees?
If the noise forecast is too loud, something needs to be done. “The solution is not a matter of taste, but a technical one – one that reduces the noise level sufficiently,” explains Lind. The most effective is still a noise barrier. High vegetation and earth embankments help in certain cases, but their effect is smaller and depends more on the time of year.
An earthen embankment actually works as well as a noise barrier as a noise barrier, it just may not be suitable for every location – an earthen embankment requires a fairly large area of land that is high enough to accommodate the embankment. The same goes for tall greenery, which has an effect on noise dispersion – to achieve the necessary effect, the forest must be several hundred meters wide, and you also have to take into account that deciduous trees are bare in winter.
The more precisely the noise model is prepared, the more accurate the solution will be. And this is not a theoretical risk calculation – it is regulated by law. “In Estonia, there is an Atmospheric Air Protection Act and, in addition, a Noise Level Regulation, which sets standards for residential areas, schools, hospitals and recreational areas,” says Lind.
If modeling indicates a potential exceedance of standards, mitigation measures must be implemented. And not only to create a borderline situation, but often with a margin to ensure a good living environment.
A noise that never came
Sometimes the biggest fear is not even the train itself, but the fear of the unknown. There are several examples in Estonia where communities were afraid of a new road or route – but when the project was completed, it turned out that life became quieter, not louder.
“There have been comparative studies where the model estimated the situation to be louder than reality. These models tend to overestimate a little to avoid underestimating,” says Lind. “This is also why a noise model is never just a theoretical exercise, but an important planning tool.”
Will we evaluate everything in the future?
In ten years, will we be able to model noise even more accurately? Maybe. But that doesn't mean that today's work is inaccurate. Rather, the methods will become faster, but the principles will remain the same.
“It remains a supporting activity – a tool for experts,” says Lind. The future modeled today is not fiction. It is based on measurable knowledge, the precision of engineers’ work, and experience that cannot be overestimated or overvalued.
When the trains start running along Rail Baltica and people living along the route hear them in their backyards, there is a good chance that the sound will be quieter than once feared when thinking about the old diesel trains. And this is no coincidence. It is the result of years of work, calculation and prevention.
The article was first published on July 11, 2025 as a content marketing story in Õhtuleht.
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