Purpose Environmental impacts are typically considered in transportation decisions through planning and environmental review processes. Recent state-level legislation in the USA institutes requirements to track environmental performance of construction materials in bidding on public projects. To support this new initiative, this study aims to identify specific life cycle assessment (LCA) frameworks that can effectively impact the decisions on every level in the planning and project delivery process and evaluate the implementation readiness level. Methods The objective of this study was pursued through literature review and discussions facilitated at a workshop with representatives of six State Departments of Transportation (DOTs). Through the dialog with stakeholders, the details of the current planning and project delivery process were identified. After the participants were provided with background on LCA, LCA methodology, the most suitable to impact decisions at every decision-making level, was investigated considering key decisions (Why?), type of the analysis (How?), available data (What?), and the involved decision-makers (Who?) pertinent to each phase. The potential to develop tools to inform the decisions, the readiness level, and obstacles to LCA implementation was evaluated subsequently by authors and informed by a literature review. Results and discussion A consequential LCA was identified as the effective method to inform long-range planning. Attributional LCAs for a network and project level were regarded as suitable in programming and project development, respectively. Environmental product declatations (EPDs) were found applicable in bidding, while the construction phase was found best suited for data collection that can feed back into the upstream decision-making phases. The lack of a feedback loop between the quantified environmental impacts and the decision-making was identified as a major obstacle by stakeholders. A lack of clarity on progress toward environmental goals was specified as another hindrance. The development of tools and systems for communication and data transfer among the key stakeholders is expected to facilitate LCA use, close a feedback loop, and provide for progress tracking. Conclusions The relatively high readiness level of LCA implementation was identified in the pavement design phase (parallel to life cycle cost analysis (LCCA)) and in the construction phase (as-built environmental impact tracking and data collection). Initiating data collection in these two phases can provide an impetus for improving environmental performance and meaningfully inform other decision-making phases. Additionally, the importance of education and cross-collaboration is recognized by all stakeholders.

中文翻译：

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将生命周期评估整合到美国路面的规划和项目交付中

目的 在运输决策中通常会通过规划和环境审查过程来考虑环境影响。美国最近的州级立法要求在公共项目投标中跟踪建筑材料的环境性能。为支持这一新举措，本研究旨在确定特定的生命周期评估 (LCA) 框架，这些框架可以有效影响规划和项目交付过程中各个层面的决策，并评估实施准备水平。方法 本研究的目标是通过文献回顾和在与六个州交通部 (DOT) 代表的研讨会上进行的讨论来实现的。通过与利益相关者的对话，确定了当前规划和项目交付过程的细节。在向参与者提供 LCA 的背景知识后，对 LCA 方法（最适合影响每个决策级别的决策）进行了调查，考虑了关键决策（为什么？）、分析类型（如何？）、可用数据（什么？ ），以及与每个阶段相关的决策者（谁？）。作者随后评估了开发工具以告知决策、准备水平和 LCA 实施障碍的潜力，并通过文献综述提供信息。结果和讨论 一个相应的 LCA 被确定为通知长期规划的有效方法。网络和项目级别的归因 LCA 被认为分别适用于编程和项目开发。发现环境产品声明 (EPD) 适用于投标，而施工阶段被发现最适合数据收集，可以反馈到上游决策阶段。量化环境影响与决策之间缺乏反馈循环被利益相关者视为主要障碍。环境目标进展不明确被指定为另一个障碍。主要利益相关者之间通信和数据传输的工具和系统的开发有望促进 LCA 的使用、关闭反馈循环并提供进度跟踪。结论 在路面设计阶段（与生命周期成本分析 (LCCA) 并行）和施工阶段（竣工环境影响跟踪和数据收集）确定了 LCA 实施的相对较高的准备水平。在这两个阶段启动数据收集可以推动改善环境绩效并为其他决策阶段提供有意义的信息。此外，所有利益相关者都认识到教育和交叉协作的重要性。