Decisions on transport plans and projects involve relevant public investments and may also determine radical changes in users’ costs. Unfortunately, it is not rare that—especially at the strategic planning stage—decisions on alternative projects or scenarios are made on a qualitative basis or, at best, by setting some indicators and verifying how much they reach the politically decided targets (e.g., “increasing the use of bicycles by 10%”). In order to reduce subjectivity, a more quantitative and comprehensive approach to the evaluation is needed. A Cost-Benefit Analysis is a tool commonly used to assess public expenditure, but its application to mobility plans introduces further practical and theoretical complexities. In this paper, we will thus try to contribute to the topic of the assessment of both sustainable mobility transport plans and infrastructure projects by presenting the operative application of a CBA methodology that is, at the same time, theoretically coherent and rich in outputs to support the decision-maker. Moreover, we will discuss the possible use of GIS software in order to provide to the decision-makers a clear and immediate “picture” of the effects on the network linked to different scenarios. The structure is as follows. Firstly, we discuss the complexities involved in the evaluation of plans with respect to a single infrastructure. Secondly, we introduce the available approaches for the assessment of consumer surplus, namely, the Rule of Half and the logsum function method, which allow the perfect integration between CBA and transport models. Thirdly, we present, through some operative case studies, the methodologies applied to the assessment and the network effects visualization of the urban mobility plan and new infrastructures. Finally, we underline how we can make the results more understandable to politicians, policy-makers, stakeholders, and citizens and in general improve the transparency and the awareness of the choices.

中文翻译：

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运输模型与成本效益分析之间的集成以支持决策实践：意大利北部的两个应用

有关运输计划和项目的决定涉及相关的公共投资，也可能决定用户成本的根本变化。不幸的是，尤其是在战略规划阶段，对替代项目或方案的决策是定性的，或者最好是通过设置一些指标并验证其达到政治确定的目标的程度来做出决定（例如，“将自行车的使用量增加10％”）。为了减少主观性，需要一种更加定量和全面的评估方法。成本效益分析是通常用于评估公共支出的工具，但是将其应用于流动性计划会带来进一步的实践和理论复杂性。在本文中，因此，我们将通过介绍CBA方法的有效应用来努力为可持续交通运输计划和基础设施项目的评估主题做出贡献，而CBA方法在理论上是连贯的，并且产出丰富，可为决策者提供支持。此外，我们将讨论GIS软件的可能用途，以便为决策者提供清晰，直接的“图片”，以了解与不同情况相关的网络影响。结构如下。首先，我们讨论有关单个基础结构的计划评估所涉及的复杂性。其次，我们介绍了可用的评估消费者剩余的方法，即半数法则和对数函数法，它们使CBA和运输模型之间能够完美地融合。第三，我们通过一些实际的案例研究，介绍了应用于城市交通规划和新基础设施评估以及网络效果可视化的方法。最后，我们强调如何使政治家，决策者，利益相关者和公民更容易理解结果，并总体上提高选择的透明度和意识。