## 3 Materials and Methods
### Overview of the Applicable Methods  
Decision-making is a key aspect of managing transport systems, which usually involves identifying and defining existing problems, generating alternative solutions (such as renovating or building new infrastructure), evaluating these solutions and selecting the optimal one. In the past, cost-effectiveness analysis was the most common assessment method in transport decision-making. However, cost-benefit analysis is widely used today. Both methods allow for analytical comparison of different inputs and outputs. It is important to point out that both methods have certain limitations, which primarily relate to the adequate and objective evaluation of all costs and effects of the examined alternatives in terms of monetary resources. For example, the unavailability of relevant data or the inability to objectively quantify certain effects (e.g., fatalities) in monetary terms. In transport projects, there is often disagreement between the participants involved, regarding the project objectives, or the relative importance of criteria or the procedure to be followed, which complicates and prolongs the entire process. Multi-criteria decision-making (MCDM) is a branch of operational research that deals with the consideration of multiple quantitative and qualitative criteria when making decisions among different solutions. The use of MCDM techniques provides a flexible and transparent approach to solving complex problems. A key part of the MCDM process is the establishment of a hierarchy of objectives (goals), criteria, and alternatives of the decision problem. The objective (goal) of the decision problem represents a general statement of the desired improvement. Some analysts prefer to structure the decision problem into several levels of objectives, where the second-level objectives correspond to the criteria, and the third-level objectives correspond to the alternatives [44]. According to [PERSON] in 2005 [45], the set of objectives in a decision problem should have the following properties: relevant, controllable, complete, measurable, operational, disaggregated, non-redundant, concise, and understandable. Objectives direct towards improvements but do not specify the means for achieving them, so it is important to avoid suggesting preferred solutions (e.g., improving the environment through better public transportation) when setting objectives, in order to prevent neglecting other, possibly better options [46]. Since the impacts of transport infrastructure projects or transport policies are wide and diverse, the spectrum of common objectives in transport sector decision-making problems is also very wide. According to [46; 47; 48; 49], the objectives commonly found in transport sector decision-making problems are economic efficiency, transport system efficiency, environmental protection, safety, equity and social inclusion, and contribution to economic growth. Objectives are abstract concepts and therefore it is difficult to measure performance against them. Criteria and alternatives are ways of measuring objectives. For example, under the objective of \"protection of the airport environment\", a possible criterion would be \"minimization of air pollution in the immediate vicinity of the airport\", and a relevant indicator could be expected CO\({}_{2}\) emissions. Possible criteria related to the above objectives in decision-making problems in the transport sector, according to the authors [46; 47; 48; 49], are economic efficiency, transport system efficiency, environmental protection, safety, and contribution to economic growth. Economic efficiency refers to the minimization of construction/implementation costs, maintenance costs, operating costs, etc. Transport system efficiency refers to the minimization of travel time, maximization of travel time reliability, minimization of congestion, maximization of quality of service, maximization of transport network capacity, maximization of passenger numbers, minimization of construction periods, etc.