## 2 Literature Review
### Cost-Benefit Analysis
The authors identify problems with quantifying non-market impacts and monetizing the total costs and benefits of transportation policies. They conclude that a CEA and CBA are useful for estimating costs and benefits but are limited in evaluating policies with marginal costs or multiple benefits. [PERSON] and [PERSON] [15] claim that the application of a quantitative assessment of the various impacts of complex transport projects can only be partial in a cost-benefit analysis. The analysis may overlook impacts on society, human life, the environment, and the built environment. According to [PERSON] et al. [16], in terms of public transport decision-making, the recommended method for selecting the optimal investment scenario is the multi-criteria analysis (MCA). It allows the inclusion of various differentiated impacts that cannot be easily valued, which is its advantage over the CBA. However, the CBA is also recommended as a complementary method for the optimal investment scenario compared to the reference scenario. [PERSON] et al. [17] address the challenges in estimating the effects of disruptions in freight transport and propose a model to estimate the value of transport time variability (VTTV). They identify four main types of disruptions and investigate methods to measure transport time variability, specifically VTTV. They propose a mathematical method for estimating VTTV for freight transport and conclude that the chosen VTTV measure should capture the properties of the transport time probability distribution. [PERSON] et al. [18] combined a retrospective CBA with a qualitative analysis. Their research, carried out in nine European countries, highlights positive economic effects such as time and operational cost savings, while also demonstrating the importance of considering social exclusion (SE) and wider economic impacts when evaluating projects. A CBA of traffic and transport projects also includes their environmental impacts and financial implications. Different approaches to calculating GHG emissions, emission patterns, and unit costs of GHGs lead to divergent results in assessing road transport developments in individual countries, which are often transnational in character and part of an international transport network. The varying approaches of countries and the results of the CBA affect prioritization, as well as the approval of the construction of transport structures. In the case of international transport corridors running through several countries, this disparity can compromise their integrity. In EU countries, the _Guide to Cost-Benefit Analysis of Investment Projects_, the latest version from 2014, is used to assess transport infrastructure projects. The Guide is an operational manual that supports the Evaluation Unit and the geographical units of DG Regional Policy, other Commission services, and Member States in need to assess and check the completeness and adequacy of applications for EU funds received by the applicant. The guide is mandatory for all major projects submitted under the 2014-2020 ESIF. The Economic Appraisal Vademecum (EAV) was published in 2021. The EAV aims to support and simplify economic appraisal for EU co-funded investments in the programming period of 2021-2027. The EAV in Annex I provides an overview of existing CBA manuals at the national level; specifically, in 16 EU countries, there are 22 manuals focusing on transport. To date, no research has been conducted in the Slovak Republic on comparing CBA procedures for assessing transport projects with an emphasis on GHG emissions and climate change costs, including the identification of disparities and an assessment of the adequacy of calculations. It is precisely the issues of climate change and transport that have received considerable attention recently.