Industrial Ecology Programme, Department of Energy and Process Engineering, NTNU - Norwegian University of Science and Technology, Høgskoleringen 5, 7034 Trondheim, Norway.
Department of Civil & Mineral Engineering, University of Toronto, 35 St. George Street, Toronto, OntarioM5S 1A4, Canada.
Environ Sci Technol. 2022 Dec 20;56(24):18050-18059. doi: 10.1021/acs.est.2c05255. Epub 2022 Dec 1.
Roads play a key role in movements of goods and people but require large amounts of materials emitting greenhouse gases to be produced. This study assesses the global road material stock and the emissions associated with materials' production. Our bottom-up approach combines georeferenced paved road segments with road length statistics and archetypical geometric characteristics of roads. We estimate road material stock to be of 254 Gt. If we were to build these roads anew, raw material production would emit 8.4 GtCO-eq. Per capita stocks range from 0.2 t/cap in Chad to 283 t/cap in Iceland, with a median of 20.6 t/cap. If the average per capita stock in Africa was to reach the current European level, 166 Gt of road materials, equivalent to the road material stock in North America and in East and South Asia, would be consumed. At the urban scale, road material stock increases with the urban area, population density, and GDP per capita, emphasizing the need for containing urban expansion. Our study highlights the challenges in estimating road material stock and serves as a basis for further research into infrastructure resource management.
道路在货物和人员的流动中起着关键作用，但需要大量生产排放温室气体的材料。本研究评估了全球道路材料存量以及与材料生产相关的排放。我们的自下而上方法将地理参考的铺砌道路段与道路长度统计数据和道路典型几何特征相结合。我们估计道路材料存量为 254 吉吨。如果我们要重新建造这些道路，原材料生产将排放 8.4 吉吨二氧化碳当量。人均存量从乍得的 0.2 吨/人到冰岛的 283 吨/人不等，中位数为 20.6 吨/人。如果非洲的人均存量平均达到目前欧洲的水平，将消耗 166 吉吨的道路材料，相当于北美以及东亚和南亚的道路材料存量。在城市规模上，道路材料存量随着城市面积、人口密度和人均国内生产总值的增加而增加，这强调了控制城市扩张的必要性。我们的研究强调了估计道路材料存量的挑战，并为基础设施资源管理的进一步研究提供了基础。
