State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESPC), School of Environment, Tsinghua University, Beijing, 100084, China; Yale School of the Environment, Yale University, 195 Prospect St., New Haven, 06511, USA.
Yale School of the Environment, Yale University, 195 Prospect St., New Haven, 06511, USA; Joint Global Change Research Institute, Pacific Northwest National Laboratory, College Park, MD, USA.
J Environ Manage. 2022 Oct 1;319:115512. doi: 10.1016/j.jenvman.2022.115512. Epub 2022 Jul 8.
The expansion of road networks in emerging economies such as China causes significant greenhouse gas (GHG) emissions. This development is conflicting with China's commitment to achieve carbon neutrality. Thus, there is a need to better understand life cycle emissions of road infrastructure and opportunities to mitigate these emissions. Existing impact studies of roads in developing countries do not address recycled materials, improved pavement maintenance, or pavement-vehicle interaction and electric vehicle (EV) adoption. Combining firsthand information from Chinese road construction engineers with publicly available data, this paper estimates a comprehensive account of GHG emissions of the road pavement network to be constructed in the next ten years in the Shandong province in Northern China. Further, we estimate the potential of GHG emission reductions achievable under three scenario sets: maintenance optimization, alternative pavement material replacement, and EV adoption. Results show that the life cycle GHG emissions of highways and Class 1-4 roads to be constructed in the next 10 years amount to 147 Mt CO2-eq. Considering the use phase in our model reveals that it is the dominant stage in terms of emissions, largely due to pavement-vehicle interaction. Vehicle electrification can only moderately mitigate these emissions. Other stages, such as materials production and road maintenance and rehabilitation, contribute substantially to GHG emissions as well, highlighting the importance of optimizing the management of these stages. Surprisingly, longer, not shorter maintenance intervals, yield significant emission reductions. Another counter-intuitive finding is that thicker and more material-intensive pavement surfaces cause lower emissions overall. Taken together, optimal maintenance and rehabilitation schedules, alternative material use, and vehicle electrification provide GHG reduction potentials of 11%, 4%-16% and 2%-6%, respectively.
在新兴经济体（如中国），道路网络的扩展导致了大量的温室气体（GHG）排放。这一发展与中国实现碳中和的承诺相冲突。因此，需要更好地了解道路基础设施的生命周期排放及其减排机会。现有的发展中国家道路影响研究并未涉及回收材料、改善路面维护或路面-车辆相互作用以及电动汽车（EV）的采用。本文结合中国道路建设工程师的第一手信息和公开可用数据，估算了中国北方山东省未来十年将要建设的道路路面网络的温室气体排放综合情况。此外，我们还根据三种情景集估算了 GHG 减排的潜力：维护优化、替代路面材料的替代和电动汽车的采用。结果表明，未来 10 年山东省将要建设的高速公路和 1-4 级道路的生命周期 GHG 排放量达到 147 Mt CO2-eq。考虑到模型中的使用阶段，发现它在排放方面是主要阶段，主要是由于路面-车辆相互作用。电动汽车的采用只能适度减少这些排放。其他阶段，如材料生产和道路维护和修复，也对 GHG 排放做出了重大贡献，突出了优化这些阶段管理的重要性。令人惊讶的是，较长的而不是较短的维护间隔可以显著减少排放。另一个违反直觉的发现是，较厚和更密集的材料路面表面总体上会导致较低的排放。总的来说，最佳的维护和修复计划、替代材料的使用以及电动汽车的采用分别提供了 11%、4%-16%和 2%-6%的 GHG 减排潜力。
