Yes / The surface transport infrastructure (i.e. road and rail) has seen increasing pressure in recent years to achieve better sustainability performance. Transport Noise Reducing Devices (NRDs) form a major part of the surface transport infrastructure system in mitigating undesirable surface noise pollution to impacted communities. Their sustainability is a growing interest for practitioners and policy makers in this area as NRDs projects now have to balance integrating and assessing social, environmental, and economic objectives besides meeting key technical requirements. This paper presents an account of the first study carried out to assess the absolute sustainability of NRDs via the application of multi criteria analysis (MCA) techniques. The general procedure, selection of criteria, data gathering, and the use of three MCA techniques, SAW (Simple Additive Weighting), PROMETHEE (Preference Ranking Organisation MeTHod for Enrichment Evaluations), and ELECTRE III (Elimination et Choice Translating Reality), to assess the absolute sustainability of two built and operating European NRDs projects (one in Spain, and one in Italy) is presented. The novel concept of defining an Optimal Hypothetic Ideal Solution (OHIS) to assess the sustainability of NRDs in absolute terms to achieve this end is also introduced and discussed. The presented case studies will thus provide a useful model for practitioners to adopt or amend to conduct their own assessments of NRDs' sustainability. The paper further concludes that the generation of index values by the three MCA techniques to denote the overall absolute sustainability of solutions is a useful feature for communicating the sustainability of NRDs across a broad range of stakeholders, and for conducting “what-if” analyses. The presented research could also support broader aims of developing harmonized sustainability standards for the NRDs industry to adopt and so forward the sustainability transport agenda.

Yes / The top-down-bottom-up (TDBU) methodology for defining bespoke sets of sustainability criteria for specific civil engineering project types is introduced and discussed. The need to define sustainability criteria for specific civil engineering project types occurs mainly in one or both of the following cases: (1) when a more comprehensive and indicative assessment of the sustainability of the project type in question is required; and/or (2) there is no readily available bespoke sustainability assessment tool, or set of criteria, for assessing the sustainability of the project type. The construction of roads, buildings, airports, tunnels, dams, flood banks, bridges, water supply, and sewage systems and their supporting systems are considered to be unique civil engineering/infrastructure project types. The normative definition of sustainable civil engineering/infrastructure projects and the framework for assessing its sustainability is defined and provided by the authors. An example of the TDBU methodology being applied to define sustainability criteria for transport noise reducing devices is presented and discussed. The end result of applying the methodology is a systematically researched and industry validated set of criteria that denotes assessing the sustainability of the civil engineering/infrastructure project type. The paper concludes that the top-down-bottom-up will support stakeholders and managers involved in assessing sustainability to consider all major research methods to define general and unique sustainability criteria to assess and so maximize sustainability.

Bullerskyddsskärmar används för att reducera buller från väg- och spårtrafik. Syftet med examensarbetet var att utvärdera standard EN 1793–6:2012, en mätmetod för att undersöka bullerskyddsskärmars effektivitet in-situ med avseende på ljudisoleringen. I nuläget bestäms bullerskyddsskärmars effektivitet med laborationsmätningar i ett diffust ljudfält, som inte överensstämmer med det direkta ljudfält och den komplexitet som är in-situ. Till följd av det blir ofta laborationsmätningarna missvisande. Det finns även en okunskap kring håligheter/ läckage och hur det påverkar den akustiska prestandan, vilket gör att det emellanåt leder till brister i installationen av bullerskyddsskärmar och att enhetens ljudreducering inte stämmer överens med förväntningarna. Det finns således ett behov av att bestämma en bullerskyddsskärms befintliga prestanda in-situ för att säkerställa de krav som ställs i specifikationerna. EN 1793–6:2012 ansågs vara lämplig för ändamålet men fler mätningar behövs utföras för att kunna säkerställa resultaten och för att verifiera mätsystemet. Ljudisoleringen bestämdes som en funktion av frekvenser i tersband och var giltiga i frekvensområdet mellan 200 Hz till 5 kHz respektive 400 Hz till 5 kHz. De undersökta bullerskyddsskärmar var: en i laminerat och härdat glas med aluminiumpelare, en icke-homogen vegetationsskärm i stålram och en kombinerad bullerskyddsskärm i akrylglas med aluminiumprofiler. Resultaten jämfördes med laborationsmätningar och/eller simuleringar i Insul. Bullerskyddsskärmarna i glas gav högre värden på ljudisoleringen än i laborationsmätning, ett resultat som kan bero på skillnaderna mellan diffust ljudfält och direkt ljudfält. Komplexiteten i vegetationsskärmen gjorde resultaten svåra att analysera, men läckage förekom i de högre frekvenserna. Adrienne-fönstren behövde bli specifikt beräknade för samtliga impulssvar eftersom dimensionerna för bullerskyddsskärmarna inte överensstämde med vad som definieras i EN 1793–6:2012 för certifieringsändamål. I EN 1793–6:2012 omnämns inte heller markreflektion, som påverkar den filtrerade signalen. Vidare studier behövs för att filtrera bort dessa oönskade komponenter. / Road traffic noise devices, for example noise barriers, are used to reduce the noise from road traffic and trams. The purpose of this master thesis is to evaluate the standard EN 1793-6:2012, a test method for determining noise barriers efficiency in-situ. Currently, noise barriers efficiency is determined with laboratory measurements in a diffuse sound field, which does not reflect the direct sound field and the complexity that are in-situ. As a result, laboratory measurements are often misleading. Due to a lack of knowledge about leakage, there are sometimes defects caused in the installation of the noise barriers that adversely affect the acoustic properties. There is thus a need to determine the intrinsic parameters of a noise barrier in-situ to ensure the requirements set in the specifications. The new method described in EN 1793-6:2012 was considered useful for the purpose but it was found that more measurements need to be performed to ensure results and to verify the measurement system. The sound insulation was determined for three noise barriers where results are expressed as a function of frequency in one third octave band and were valid in the frequency range between 200 Hz to 5 kHz respective 400 Hz to 5 kHz. The noise barriers tested were: a barrier in laminated glass with metal posts, a non-homogeneous vegetation barrier in a steel frame and a combined barrier with acrylic glass and metal. The results were compared with laboratory measurements and/or simulations in Insul. The glass barriers showed higher values ​​of the sound insulation index than the laboratory measurements, perhaps due to the different sound fields. The complexity of the vegetation barrier made the results difficult to analyze, but leakage occurred in the higher frequencies. The Adrienne temporal windows were specifically calculated for all impulse responses, since the dimensions of the noise barriers differed from the one defined in EN 1793-6: 2012 for certification purposes. Also, in EN 1793-6: 2012, ground reflection, which affects the filtered signal, is not mentioned. Further studies are needed to filter out these unwanted components.