Material stock development of the transport sector in the city of Vienna

Abstract

Societies aim to reduce primary raw material consumption, enhance waste recycling, and reduce waste disposal. In this regard, the circular‐economy concept has gained attention and is applied in policy papers, also on the urban level. However, to assess set targets and their achievement, a sound knowledge of anthropogenic material flows and stocks is required. The material turnover of transport systems has not been sufficiently investigated yet, although they have a significant impact on overall material turnover and have a high potential for making use of recycled construction materials. To close this gap, the present study investigates the anthropogenic stocks and flows related to an urban transport system, whereby both infrastructure and vehicles are included. A bottom‐up, multiyear material‐flow analysis was employed to calculate the material stock and the related input and output flows of Vienna's transport system for the period 1990–2015. The results indicate the increasing importance of more environmentally friendly modes of transport. The stock of motorized individual transport has increased in absolute terms since 1990, but the stock per capita remains unchanged at 34 t/cap, whereas the per capita stock of public transport (20 t/cap; +8%) and of non‐motorized individual transport (4 t/cap; +10%) has increased. However, the primary source of material consumption (>65%) is maintenance of infrastructure. This provides a potential for more circularity because outputs and inputs are equal in terms of mass and material. The study provides a systematic analysis for developing policy and management options for sustainable resource‐saving urban transport systems.

High-Resolution Maps of Material Stocks in Buildings and Infrastructures in Austria and Germany

“…73 − 75 We compared results on the mass of material stocks by type and material against the available literature sources. 12 , 39 , 50 − 52 , 64 , 65 , 70 , 76 − 78 Detailed documentation and discussion of the validations are available in the SI ; findings are summarized in the Section 3 .…”

Mining the Built Environment: Telling the Story of Urban Mining

“…Furthermore, the literature shows an interest in quantifying the current and future waste flows. The general methodology of such research can be described as a retrospective stock pattern estimation that allows a prospective forecasting model for future waste generation to be created [41][42][43][44][45][46][47][48][49][50][51][52][53] Production and consumption: This category included research that focused on the evolution of stocks and flows over time, highlighting the increasing consumption and accumulation of stocks [20,22,49,[54][55][56][57][58][59][60][61][62][63][64][65][66][67]. Typically, it included forecasting future demand, similar to the general methodology described in the previous category.…”

Global urban subway development, construction material stocks, and embodied carbon emissions

“…The past years have seen several studies on characterizing the quantity, quality, and composition of urban infrastructure stocks such as roads (Nguyen et al, 2019), highways (Guo et al, 2017), railways (Wang et al, 2016), and water pipes (Pauliuk et al, 2014). However, only a few of these studies have specifically addressed subway system for a handful case cities, e.g., Vienna (Lederer et al, 2016b;Gassner et al, 2020), Toronto (Saxe et al, 2017), Beijing (Mao et al, 2020), and Shanghai (Han et al, 2018). Furthermore, a few knowledge gaps remain unaddressed in these case studies on subway stocks:…”

“…The subway stock results are often derived from statistics in aggregated values (Gassner et al, 2020;Saxe et al, 2017), thus the spatial patterns and material stocks distribution are not analyzed, which would be essential for practical urban mining and waste management (e.g., for spatial planning and optimization of waste supply and demand).…”

“…• Previous studies often address individual cities, so cannot benchmark subway material stocks results across cities and reveal spatiotemporal variations and growth patterns in the long run. For example, the subway material stocks contributed to 13.9% of materials in Vienna's transport sector (Gassner et al, 2020), while only accounted for 2.6% and 0.5% in the urban built-environment stocks of Beijing (Mao et al, 2020) and Shanghai (Han et al, 2018), respectively. Moreover, the quantity, composition, location, and embodied GHG emissions of the global subway material stocks are hitherto poorly understood at the global level.…”