An extensive technological shift is currently taking place to mitigate climate changeand this trend is particularly noticeable in the transport sector. This is interestingfrom an acoustical perspective, since it changes the noise environment in society.For example, a study in Gothenburg has shown that a complete electrification ofthe road traffic would reduce the noise levels by between 2 and 5 dB(A). In Sweden,noise emissions are calculated with a calculation model from 1996, called the Nordiskberäkningsmodell (Nordiska). Given the age of the model it is reasonable to investigate whether Sweden should change completely to the EU-common calculationmodel Common NOise aSSessment methOdS (CNOSSOS), since it is mandatory touse for national noise mapping. This master thesis has performed a computation analysis to compare and discussdifferences between CNOSSOS and Nordiska, to contribute to answering the question whether Sweden should change to CNOSSOS (or perhaps another model). Theresults show that CNOSSOS overall computes higher noise levels than Nordiska andthat the differences between them increase linearly with distance. Farthest from thenoise source the differences are up to 5 dB(A) for the road case and 9 dB(A) forthe railway case. In other words, the differences are larger for the railway trafficmodels than they are for the road traffic models, which is thought to be a result ofthe complexity of the CNOSSOS railway model. Another interesting phenomenonis that the differences behind buildings between the models are different for roadand railway traffic, which can be explained by the fact that the screening effects inNordiska’s road and railway models are different. My conclusion is that CNOSSOS is unsuitable for domestic calculations of noiseemissions. The model does not align with Swedish legislation and there is uncertaintydue to the fact that the differences between the CNOSSOS and Nordiska road andrailway models are different in size. Moreover, CNOSSOS railway model requires alot of computational power, which can delay and increase the costs of noise mappingor reduce the accuracy of the results. However, additional work is needed in whicheach calculation model is compared with measurements in situ to see which modelbest describes reality. If the conclusion thereafter is that CNOSSOS still is not asuitable option, it could be examined whether it is possible to create an updatedversion of Nord2000 (another Nordic calculation model used e.g. in Denmark) toobtain a calculation model that is more suitable for future traffic conditions. / För att minska effekterna av de pågående klimatförändringarna pågår idag ett omfattande teknikskifte för bland annat väg- och spårburen trafik. Detta skifte är intressant ur ett akustiskt perspektiv eftersom det förändrar bullermiljön i samhället.Till exempel har en studie i Göteborg visat att en full elektrifiering av vägtrafiken hade reducerat bullernivåerna med mellan 2 och 5 dB(A). Bullret beräknasmed en beräkningsmodell och i Sverige används idag Nordisk beräkningsmodell från1996 (Nordiska). Givet att modellen är gammal finns det god anledning att utredaom Sverige borde byta helt till den EU-gemensamma beräkningsmodellen CommonNOise aSSessment methOdS (CNOSSOS), som dessutom är obligatorisk vid dennationella bullerkartläggningen. Detta examensarbete har gått ut på att utföra en beräkningsanalys i syfte att jämföra och diskutera skillnader mellan CNOSSOS och Nordiska, vilket är ett steg i attbesvara frågan om Sverige borde byta till CNOSSOS (eller kanske någon annan beräkningsmodell). Resultaten visar att CNOSSOS överlag beräknar högre ljudnivåerän Nordiska och att skillnaderna dem emellan ökar linjärt med avståndet. Längstbort från bullerkällan uppgår skillnaderna som mest till 5 dB(A) för vägfallet och9 dB(A) för spårfallet. Skillnaderna är alltså större för spårmodellen än de för vägmodellen och det tros bero på komplexiteten i CNOSSOS spårmodell. Ett annatintressant fenomen är att skillnaderna bakom byggnader är olika stora för väg- ochspårtrafik, vilket förklaras med att skärmeffekten i Nordiskas väg- och spårmodellär olika. Min slutsats är att CNOSSOS inte är lämplig för inhemska beräkningar. Modellenkrockar med svensk lagstiftning samtidigt som det föreligger en osäkerhet i att skillnaderna mellan väg- och spårmodellerna är olika stora. Därutöver kräver CNOSSOSspårmodell mycket datorkraft, vilket kan fördyra och fördröja bullerutredningar ellerminska noggrannheten i beräkningsresultat. För att säkert besvara frågan anser jagdock att man behöver utföra ytterligare arbete där respektive beräkningsmodell jämförs med mätningar in situ för att se vilken modell som stämmer bäst överens medverkligheten. Kommer man därefter fram till att CNOSSOS inte är ett alternativbör man utreda om det är möjligt att skapa en uppdaterad version av Nord2000 (enannan nordisk beräkningsmodell som används bland annat i Danmark) i syfte att fåen beräkningsmodell som är bättre anpassad för framtida trafikförhållanden.

The public interest in central living in today’s cities has led to an increasing effect of traffic noise pollution, and today 20% of the inhabitants in Sweden suffer from noise a level that exceeds the limits. At the same time the traffic keeps increasing, and recent researches shows that traffic noise pollution and several of today’s most common health issues are connected, for example, reduction of performance, sleeping issues and cardiovascular diseases. For this cause rules, guidelines and environmental goals has been developed, as well as software’s which calculates the levels of pollution, all this to investigate and improve the environment. The guidelines say that the average sound pressure level shouldn’t exceed 55 dBA over 24 hours of the façade, and the maximum level shouldn’t exceed 70 dBA. Today’s issue is that the guidelines isn’t legally binding and therefore they don’t have to be fully achieved which can led to confusion and unfair interpretations in the matter of a building can or cannot be built according to the limits of traffic noise pollution.   The intensions of this report are to improve the urban environment regarding traffic noise pollution and to increase the understanding and knowledge how this issue affects urban areas. The report will also investigate and compare two different calculation methods for traffic noise pollution, the Nordic propagation method and the Nord 2000.   On this basis a literature survey has been done regarding the noise pollution issues in our cities with its rules, guidelines, objective goals, measures and the two different calculation methods. Investigations of different shapes of a building has been done in combination with the software for calculation of road traffic noise Soundplan, and a case study of a site which is located in the centre of Jönköping. The workflow has been reversed from the “normal”, were the building were designed after the limits of the noise levels were investigated. This resulted in a residential proposal which is optimized from a traffic noise point of view, and uses its own body as a shield. The condoles are directed away from the source of noise and the parking space are placed towards the roads. The final result has been analysed with both of the calculation methods, were a slightly differentiation between the methods can be seen. This is causes by the way the calculation methods deal with information and the differentiation in the calculation methods.   The conclusions from this report are that the traffic noise pollution is one of our major health issues which still are increasing. The main problem in this is that there’s several unmeasurable parameters which influences the way an individual experiences the sound environment, which contributes to the difficulty to establish a proper regulations and standards. Regarding the calculation methods there is issues to use Nord 2000, because the method requires large amounts of information which can be difficult to access. At the same time the Nordic propagation method can show incorrectly results because it hasn’t the same ability to adapt to the specific conditions at each location.