## 2 Theoretical Framework: Definitions and Classifications
### Assumptions of Sustainable Transport Development  
In analyzing the literature on transport solutions, it is essential to consider the concept of sustainable transport development and its key principles. According to the Organization for Economic Co-operation and Development (OECD), sustainable transport is one that does not endanger public health and meets the needs for access consistent with the use of renewable resources below their rates of generation, and use of non-renewable resources below the rates of development of renewable substitutes [85]. The Centre for Sustainable Transportation (CST) provides a more detailed explanation. It states that a sustainable transportation system is one that: \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Type of Crisis** & \multicolumn{2}{c}{**Distinguishing Symptoms**} & \multicolumn{2}{c}{**Impact on the Transport Sector**} \\ \hline Economic crisis & \(\bullet\) & Sharp decline in market values and asset prices, and an increase in unemployment and inflation & \(\bullet\) & Lower demand for travel due to costs [66] \\  & \(\bullet\) & Reduction in production and decline in investment and consumption & \(\bullet\) & Decrease in freight transport volumes [67] \\  & \(\bullet\) & Bankruptcies, financial problems, and falling incomes at the corporate and individual levels & \(\bullet\) & Society’s shift toward public transport [68] \\ \hline Environmental (ecological) crisis & \(\bullet\) & Includes degradation of natural resources (air, water, and soil) & \(\bullet\) & Limitations on the availability of raw materials for vehicle production [70] \\ Environmental (ecological) crisis & \(\bullet\) & Visible in the form of damage to the natural environment (forest fires and species extinction) & \(\bullet\) & Growing demand for more ecological forms of transport [71] \\  & \(\bullet\) & Related to natural processes (e.g., global warming). & \(\bullet\) & Rising prices of conventional fuels [72] \\ \hline Health crisis & \(\bullet\) & Directly affects the health of the population & \(\bullet\) & Decrease in demand for passenger transport, especially public transport [15] \\  & \(\bullet\) & Sharp increase in demand for medical services & \(\bullet\) & Declining interest in tourist trips [13] \\  & \(\bullet\) & Rapid spread of diseases (epidemics and pandemics) & \(\bullet\) & Change of preferences regarding the choice of means of transport [73] \\  & \(\bullet\) & The need to apply preventive measures & \(\bullet\) & Disruptions in global supply chains and changes in the structures of transported goods [74] \\  & \(\bullet\) & (quarantine and personal protective equipment) & \(\bullet\) & Inequality in access to transportation [77] \\ \hline Social crisis & \(\bullet\) & Destabilizes basic social structures & \(\bullet\) & Declining demand for travel due to safety concerns [75] \\  & \(\bullet\) & Weakens the sense of collective identity and social ties & \(\bullet\) & Problems with ensuring the safety of transport infrastructure [76] \\  & \(\bullet\) & Provokes mass reactions (protests, strikes, and social movements) & \(\bullet\) & Inequality in access to transportation [77] \\  & \(\bullet\) & Causes social transformation, often influencing subsequent generations & \(\bullet\) & Inequality in access to transportation [77] \\ \hline Military crisis & \(\bullet\) & Direct threat to the lives of the population as a result of military operations & \(\bullet\) & Destruction of transport infrastructure [78] \\  & \(\bullet\) & Includes the use of armed forces (troops, weapons, and equipment) & \(\bullet\) & Air and sea space restrictions [79; 80] \\  & \(\bullet\) & Causes physical destruction of infrastructure & \(\bullet\) & Suspension of international connections [81] \\  & \(\bullet\) & Results in the declaration of martial law and mobilization and in taking action at the state level & \(\bullet\) & Threat of attack on transports [82] \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Comparison of crisis types and their impact on transport.