Assessing the Sustainability of Transport Systems through Indexes: A State-of-the-Art Review

Abstract

The transportation sector significantly impacts economic development; however, its sustainability is challenged, particularly due to the increase in urban vehicle numbers and the associated negative consequences. In response, diverse evaluation methods have been introduced to assist decision-makers in assessing sustainability, accompanied by the development of numerous indicators to monitor the progress of sustainable transport systems. Consequently, the evaluation of the transport system has become crucial. This study conducts a comprehensive literature review on existing approaches used to assess transport sustainability through composite indicators. The analysis began by selecting articles using keywords like “sustainable transport”, “sustainability indicators”, “composite index”, and “assessment”. Subsequently, 61 relevant articles were identified, and only 47 studies from the period 2002–2022 were selected. The analysis was completed by synthesizing the literature and presenting the findings. The examination of literature trends revealed a limited focus on freight transport, with most studies concentrating solely on traditional sustainability dimensions. Additionally, the analysis highlighted the significant impact of various normalization, weighting, and aggregation methods on composite indicator results. Finally, recommendations for precise sustainability assessments are provided to guide future research endeavors.

Sustainable Transport in the European Union: Exploring the Net-Zero Transition through Confirmatory Factor Analysis and Gaussian Graphical Modeling

“…Net-zero transition of the transport sector is an intensely debated issue among scholars, its achievement being appreciated as a growing challenge, in the context of increasing the need for mobility, its significant impact on economic development and the associated negative environmental consequences [29]. In fact, the gap between the importance of transport system development and its negative consequences is rapidly widening [36], with scholars working to identify solutions to limiting the environmental degradation and threat to human health.…”

“…Moving further in the assessment of transport sustainability, refs. [24,25,29] have proposed an extension of the classical dimensions (economic, social, environmental) by including additional categories related to political and spatial aspects of the transport system [29] and, in particular, urban freight transport [24,25]. The same approach was followed by [26] in assessing the sustainability of rail transport.…”

“…To address this challenge, many studies have approached the sustainability of transport modes in relation to its economic, environmental and social dimensions [3,23]; other papers have included additional dimensions of sustainability, related to political and spatial issues [24,25] or technology aspects [26]; meanwhile, some studies have focused exclusively on its social and environmental pillars [22,27]. With the concept of sustainable development at its core, most commonly in line with the definition of the Brundland Commission report in 1987 [28], a "special attention has been paid to sustainable transport" [29] (p. 1).…”

“…Taking into consideration its different dimensions, the progress of transport sustainability has been assessed, from a systemic perspective, through a collection of indicators [3,23] or a composite index [22,29], while another part of the literature has focused on transport emissions as the core of sustainability and investigated the influence exerted on gas emissions by different determinants, such as policies, environmental technologies, value-added and infrastructure investments [30], energy efficiency and decarbonization policies [7], innovations in transport, green taxes and trade globalization [31], GDP, environmental technologies and renewable energy [32]; and economic growth, energy consumption and urbanization [33]. It should be noted that previous studies have approached transport sustainability in a predominantly classical manner, with investigations aimed at identifying appropriate measures for monitoring and improving transport performance [3,22,23,29] or at quantifying the isolated influence of different factors on transport emissions [7,[30][31][32][33].…”