针对道路建养运碳排放边界复杂、主体多元、排放活动数据时空分散等问题，本文从交通领域碳管理需求出发，提出了一种适用于多主体前期碳管理核算布局、建养运多阶段核算优化以及现场与供应链计量一体化的通用核算方法。围绕核算边界界定、核算主体与核算单元映射、排放活动因子采集与排放因子匹配、工程/运输多层级融合碳排放核算、车辆运输环节碳核算、碳排放结构分析与热点识别，以及减碳路径筛选、效果评价与治理等环节，系统分析并论证了面向道路建养运多阶段、多主体、多目标的通用碳核算、减碳与治理方法的构建基础和实施要点，并通过两个案例说明了该方法的通用性。研究发现，复杂公路工程在施工图设计阶段注重减碳技术应用，可使碳排放降低10%以上，但不同分部工程的减碳效果并不稳定；施工阶段的材料循环利用和工艺工法优化同样具有显著的减碳潜力。对于城市交通碳排放核算及未来情景推断，研究表明，只有推进能源替代与综合交通体系全面优化，才能实现2030年交通碳达峰目标。本文方法可为交通运输行业的转型升级提供机理解析、技术寻优与治理提升等多方面的支撑。

To address the challenges of complex carbon emission boundaries, multiple responsible entities, and spatiotemporally dispersed emission activity data in road construction, maintenance, and operation, this study proposes a general accounting method based on the carbon management needs of the transportation sector. The method is applicable to preliminary carbon accounting arrangements for multiple entities, multi-stage accounting optimization for road construction, maintenance, and operation, and the integrated measurement of on-site and supply-chain emissions. Focusing on accounting boundary definition, mapping between accounting entities and accounting units, emission activity data collection, and emission factor matching, multi-level integrated carbon emission accounting for engineering and transportation activities, vehicle transportation carbon accounting, carbon emission structure analysis and hotspot identification, as well as carbon reduction pathway screening, effect evaluation, and governance, this study systematically analyzes and demonstrates the theoretical basis and implementation points of a general carbon accounting, reduction, and governance method for multi-stage, multi-entity, and multi-objective road construction, maintenance, and operation. The general applicability of the method is further illustrated through two case studies. The results show that, for complex highway projects, emphasizing the application of carbon reduction technologies at the construction drawing design stage can reduce carbon emissions by more than 10%. However, the reduction effects vary across different sub-projects. During the construction stage, material recycling and process optimization also show significant carbon reduction potential. For urban transportation carbon emission accounting and future scenario projection, the results indicate that the 2030 carbon peaking target for urban transportation can only be achieved through the combined advancement of energy substitution and comprehensive optimization of the integrated transportation system. Overall, the proposed method can provide support for mechanism analysis, technology optimization and governance improvement in the transformation and upgrading of the transportation sector.