Sustainable Transport Sector Research Articles

Transport sustainability – a bibliometric, systematic methodological review and future research opportunities

Purpose Over the past decade, achieving sustainability in the transport sector has become a significant concern for governments and stakeholders. In this context, this study aims to comprehensively analyse the existing literature to document contributions and methodological deficiencies and pave the way for future research. Design/methodology/approach The authors used thematic, bibliometric and methodological systematic reviews of 39 articles across 30 sources from 112 authors between 2005 and 2023. Findings Using the Biblioshiny, the bibliometric analysis unveils the top prolific authors, contributing sources, most productive countries, top-cited papers and evolving keywords in advancing transport sustainability literature streams. The analyses revealed two strands of literature (those from the composite perspective and the triple-bottom-line perspective). The authors further consolidated indicators to measure the three pillars of transport sustainability comprehensively. Originality/value This paper uses a holistic approach to provide a state-of-the-art understanding of transport sustainability useful for the net zero or sustainable transport agenda. This paper is among the few attempts to consolidate indicators to measure transport sustainability from the triple bottom line perspective, whilst also offering exciting directions for future studies and inspiring hope for a more sustainable transport sector.

Eco-Friendly Drive: Extending The Theory of Planned Behaviours Towards Electric Vehicle Adoption

Global carbon dioxide emissions have seen a drastic increase, with the United States, European Union, China, and India being the largest contributors. In response to this pressing issue, the United Nations has adopted the Sustainable Development Goals (SDGs) to combat poverty, protect the environment, and ensure global peace and prosperity. Malaysia has also experienced a rise in carbon dioxide emissions, particularly from energy consumption, which is largely attributed to fossil fuel usage. To address these challenges, the integration of electric vehicles (EVs) into the Malaysian economy has emerged as a promising avenue for sustainable development and to support the SDGs. The Malaysian government has committed to promoting sustainability and inclusivity, with a goal of achieving net-zero carbon emissions by 2050. Therefore, this study aims to understand the factors influencing consumer purchase intention towards EVs in Malaysia. The study is grounded in the Theory of Planned Behaviour (TPB), which posits that behavioural intention is influenced by attitude towards the behaviour, subjective norm, and perceived behavioural control. Using a cross-sectional study design with a sample size of 250, the study targets individuals aged 18 and above, holding a driver's license, with driving experience, and currently non-electric vehicle users. The research employs multiple linear regression to test the hypotheses. The findings contribute significantly to knowledge by supporting government policies for improving EV adoption and providing insights for industry players on promoting EVs. Overall, the study aims to pave the way for a more sustainable transportation sector in Malaysia, aligning with global efforts to combat climate change.

Towards greener freight transport networks: An integrated model for location planning and carbon regulation policy evaluation

This paper proposes a mathematical model to assist governmental planning in the transport sector by suggesting optimal locations for logistics integration centers considering intermodality, logistics costs, and carbon costs. Seven scenarios were evaluated considering the assessment of carbon-tax and carbon-cap policies. The findings showed that logistic costs are more significant than carbon costs across the network investigated. Only non-competitive conditions such as considering carbon costs alone or adopting outrageous values for the carbon tax could change this situation. If no facility were opened, the total cost would be 2.8 times higher than the baseline scenario, while intermodality would reduce the baseline emissions by up to 3.753%. Therefore, the government should prioritize greener strategies and modal shifts in addition to implementing carbon policies to ensure a more sustainable and cost-effective transportation sector.

Enhancing Sustainability in Transportation Education: A Multimodal Curriculum Approach

This research critically examines the integration of sustainability principles into transportation education, focusing on multimodal curriculum development. Qualitative research methods are employed to investigate the perspectives of 39 cadets studying multimodal transportation, logistics, transportation safety, and law and road management at a transportation institution. The findings reveal varying levels of awareness and integration of sustainability in education, with participants highlighting the need for a more comprehensive and practical curriculum. Participants also emphasize the importance of industry collaboration, research, and policy advocacy in enhancing sustainability focus. The research underscores the urgency of preparing future professionals for the globalized, environmentally conscious transportation industry. By incorporating participants' suggestions, educational institutions can enhance sustainability education and contribute to a more sustainable and resilient transportation sector.

Assessment of impacts of critical mineral resources on sustainable transport sector

The sustainability of the transportation sector, particularly through the growth of the EV market, has become a critical issue for mineral-rich economies due to the role of key minerals like lithium in EV batteries. This study assesses how expanding lithium production affects the EV market in the top 10 EV markets from 2010 to 2022. Results show a 1% increase in lithium production is linked to a 0.58% rise in EV sales, driven by improved battery supply stability and lower costs. Technological advances in lithium-ion batteries boost efficiency and address range concerns. Additionally, a 1% increase in renewable energy generation leads to a 0.25% rise in EV sales, driven by a preference for eco-friendly transport. However, patent innovation has minimal immediate impact on EV sales, and urbanization negatively affects them due to congestion. Recommended policies include competitive tenders, green procurement, purchase subsidies, and green finance to enhance mineral markets and sustainable transportation.

The impact of the urban traffic on the CO2 intensity: a navigation study using GNSS application in Jakarta city

ABSTRACT Massive traffic congestion is one of the many challenges faced by Jakarta as the capital city of Indonesia with the largest metropolitan area. The overarching goal of the study is to explore a combination of global navigation satellite system (GNSS) with vehicle-based measuring devices to precisely map the impact of the urban traffic on the CO2 emissions in Jakarta city. The research objectives include to examine and understand the CO2 intensity in major cities using state-of-the-art research strategies to correctly map the impact of the urban traffic patterns on urban areas and overall well-being of people in these locations. Urban traffic was studied in selected major urban transportation routes that were selected using PPK GNSS and the HT 2000 environmental sensor. This study reports that there is indeed a correlation between urban traffic and air pollution. The study noted that the macro and micro parameters of urban development and traffic policies are influencing the slowing down of traffic in city centers. The research outcomes could serve as a framework for designing the conceptual smart measure and tool of transportation carbon pricing in achieving the more sustainable transportation sector of Indonesia.

Comparison Of A Molecularly-Controlled Combustion Engine To A DISI Engine

In addition to the increased use of electromobility, significant improvements in the efficiency of internal combustion engines (ICE) to achieve a considerable reduction of emissions is crucial to advance the transition towards a sustainable transport sector. One approach to increase the efficiency of combustion engines is active pre-chamber ignited engines (Molecularly Controlled Combustion Engines, MCC). The traditional spark ignition is replaced by a chamber that ignites a secondary fuel. The burning fuel is emitted from the pre-chamber via multiple holes, igniting the fuel air mixture in the main combustion chamber. To eject the flame jets tangentially to the pent roof, the pre-chamber protrudes into the main chamber in the center of the main chamber’s pent roof. This particular geometry of an MCCengine, however, alters the flow field inside MCC-engines. To facilitate future developments around MCC-engines and to understand the interactions of the flow field with the pre-chamber, a Stereo Particle-Image Velocimetry (SPIV) study is conducted in an optically accessible MCC-engine model. Previous velocity field data, which were acquired using a Direct Injection Spark Ignition (DISI) engine configuration at the same operating point as the MCC-engine, are compared to those of the MCC-engine. Phase-averaged velocity field data of both engines acquired during the intake stroke are compared based on their in-plane velocity fields and the in-plane vorticity. The two engine configurations show significantly different magnitudes of velocity in their combustion chamber flow field. In the MCC-engine, a downwash flow component can be attributed to flow deflection caused by the pre-chamber protruding from the engine’s pent roof. One important flow feature of ICE, the tumble vortex, is analyzed for both engine configurations. An increased absolute vorticity and a different temporal development of the tumble vorticity is noted for the MCC-engine. The tumble flap, an engine component that influences the intake flow distribution, is considered a main contributor to the difference in flow velocity and tumble vorticity.

Prediction of Fuel and Exhaust Emission Costs of Heavy-Duty Vehicles Intended for Gas Transportation

This research focuses on heavy-duty vehicles intended to transport compressed natural gases, i.e., class-2 dangerous goods. The analysis includes heavy-duty vehicles powered by diesel and compressed natural gas and trailers with two body types. The body types used in the research are battery bodies and multiple-element gas containers, with pressure vessels made of composite materials (Type-4) and steel (Type-1). The paper presents the methodological procedure for predicting fuel and exhaust gas emission costs as a function of fuel consumption and transported gas quantities. The effects of different types of bodies and different types of fuel on the transported quantities of gas, vehicle mass utilization, fuel consumption, and exhaust gas emissions are shown. The obtained results show that bodies with Type-4 pressure vessels transport 44% more gas than bodies with Type-1 pressure vessels for one turn. The most cost-effective solution for emission costs is diesel-powered, newer-technology vehicles and Type-4 vessels, requiring EUR 2.82 per ton of gas. Similarly, the most economical choice for fuel costs is compressed natural-gas-powered vehicles with Type-4 bodies and a cost of EUR 19.77 per ton of gas. The research results’ practical application pertains to the selection procedures of vehicles and bodies intended for the transport of gases; they should be considered in the decision-making process, with the aim of attaining a sustainable transport sector with lower costs and less impact on the environment.

A Systematic Review on Recent Advancement in Electric Vehicle Technologies

The automotive industry is undergoing a transformative shift towards electric vehicles (EVs) in response to environmental concerns and sustainability imperatives. This paper provides brief information about emerging technologies that are propelling this transition, shaping the future of sustainable transportation. Charging infrastructure developments have made EVs more practical and accessible to consumers. Artificial intelligence is playing a pivotal role in optimizing electric vehicle performance. The adoption of these emerging technologies not only extends the driving range of EVs but also brings about significant environmental benefits. This paper highlights the incredible potential of electric vehicles to revolutionize the automotive industry and address pressing environmental challenges, offering a promising vision of a more sustainable and eco-friendly transportation sector

A review of electric vehicle hosting capacity quantification and improvement techniques for distribution networks

AbstractThe electrification of the transport sector to control the carbon footprint has been gaining momentum over the last decade with electric vehicles (EVs) seen as the replacement for conventional internal combustion engines. Economic incentives, subsidies, and tax exemptions are also paving the way for rising EV penetration in the power distribution networks. However, the exponential EV adoption requires careful technical and regulatory analysis of traditional networks to satisfy the network reliability constraints. Therefore, it would be vital to find EV hosting capacity (HC) limits of networks from a multifaceted approach involving various market players, mainly distribution system operators and EV owners. This review provides a systematic categorization of EV hosting capacity evaluation and improvement methods, thus enabling researchers and industry personnel to navigate the advancing landscape of EVs. This novel framework extends beyond the theoretical implication of diverse objective functions and HC improvement methods to the actual numerical values of EV HC across varying geographical settings. Therefore, this unique synthesis of varying aspects of EV HC facilitates the in‐depth understanding of the integration of sustainable energy and transport sector.

Analysing individual differences in car use to maintenance and discretionary leisure activities

In order to reach ambitious goals of CO2 reduction, a decrease in fossil-fuelled private transport is important. Research on car use for commuters dominates literature although transport for leisure purposes constitutes a substantial share of the total transported kilometres. This study contributes by its focus on car use to maintenance (e.g. grocery shopping) and discretionary (e.g. social visits) leisure activities. We analyse whether individual perceptions about a personal responsibility to contribute to a sustainable transport sector restricts car use, and we also control for other factors such as type of municipality, residential area and sociodemographic characteristics. The analysis is based on survey data from 1024 car users living in rural, urban or metropolitan municipalities in Sweden. Data is analysed by applying recursive bivariate probit models. The results show that those who feel a personal responsibility to contribute to a sustainable transport sector drive less when travelling, in particular to maintenance activities. As well, those who regularly commute by car are more likely to use the car also for leisure purposes, which indicates that measures aimed at reducing commuting by car may spill over to travel for leisure.

Advancements in hydrogen production, storage, distribution and refuelling for a sustainable transport sector: Hydrogen fuel cell vehicles

Hydrogen is considered as a promising fuel in the 21st century due to zero tailpipe CO2 emissions from hydrogen-powered vehicles. The use of hydrogen as fuel in vehicles can play an important role in decarbonising the transport sector and achieving net-zero emissions targets. However, there exist several issues related to hydrogen production, efficient hydrogen storage system and transport and refuelling infrastructure, where the current research is focussing on. This study critically reviews and analyses the recent technological advancements of hydrogen production, storage and distribution technologies along with their cost and associated greenhouse gas emissions. This paper also comprehensively discusses the hydrogen refuelling methods, identifies issues associated with fast refuelling and explores the control strategies. Additionally, it explains various standard protocols in relation to safe and efficient refuelling, analyses economic aspects and presents the recent technological advancements related to refuelling infrastructure. This study suggests that the production cost of hydrogen significantly varies from one technology to others. The current hydrogen production cost from fossil sources using the most established technologies were estimated at about $0.8–$3.5/kg H2, depending on the country of production. The underground storage technology exhibited the lowest storage cost, followed by compressed hydrogen and liquid hydrogen storage. The levelised cost of the refuelling station was reported to be about $1.5–$8/kg H2, depending on the station's capacity and country. Using portable refuelling stations were identified as a promising option in many countries for small fleet size low-to-medium duty vehicles. Following the current research progresses, this paper in the end identifies knowledge gaps and thereby presents future research directions.

Utilization of renewable and sustainable aviation biofuels from waste tyres for sustainable aviation transport sector

Utilization of renewable and sustainable aviation biofuels from waste tyres for sustainable aviation transport sector

Design and Construction of Hazardous Gas Detection and Control System for Electric Vehicle Cabin

Abstract: Electric vehicles (EVs) are a promising technology for achieving a sustainable transport sector due to their very low to zero carbon emissions, low noise, high efficiency, and flexibility in grid operation and integration. This chapter includes an overview of electric vehicle technologies as well as associated energy storage systems. Different types of electric-drive vehicles are presented. Also, if hazardous gas is detected inside of the cabin such as CO2 gas as a result of occupants of the vehicle, the system will open windows of the vehicle automatically. The advantage of this system is proper detection and faster response time leading to faster diffusion of the situation, compared with the manual methods. The gas sensor used in this project is MQ-7 and MQ-135 which detects the presence of hazardous gases both inside and outside of the vehicle cabin. These sensors will detect the concentration of the gas according to the voltage output of the sensor. To make the sensors operate in the control and data monitoring system, Arduino Uno was used as the microcontroller for the whole system. The circuit also includes Servo motor, buzzer, exhaust fan and LCD screen.

Optimization and analysis of a hydrogen supply chain in terms of cost, CO2 emissions, and risk: the case of Turkey

The transportation sector, which is largely dependent on oil, is faced with many problems such as the danger of depletion of fossil fuels that are harmful to the environment. Moreover, the situations such as epidemics and war cause excessive fluctuations in oil prices. Therefore, there is a need for new solutions based on alternative energy sources for a sustainable transportation sector. Hydrogen fuel cell electric vehicles (HFCEV) are one of the significant alternatives for an efficient, zero emissions and sustainable transportation system. Considering the potential investment in HFCEV technology, the need for a cost effective, green, and low risk Hydrogen Supply Chain (HSC) network infrastructure is inevitable. In this study, the HSC design of the Turkish transportation sector over a 25-year period (2026–2050) is investigated. The problem is modeled using a multi-period mixed integer linear programming (MIP) model. Three objectives are addresses: cost, carbon dioxide (CO2) emissions and safety risk. In order to consider the uncertainty in the hydrogen demand, five different scenarios are analyzed using fuzzy concept. There are four main results. First, unit hydrogen cost is found to be very high due to low demand and high capital cost in the initial period (2026–2031). Second, HSC network is established in a decentralized setting in all scenario solutions. The level of decentralization gets stronger over time and with increasing demand. Third, short-distance road transport is generally preferred for hydrogen transport. Fourth, since the aim is to minimize cost, CO2 emissions, and risk level, a mixed production strategy based on cost-oriented SMR and zero-emissions-oriented Electrolysis (ELE) is observed in all scenarios.

Energy and Environmental National Assessment of Alternative Fuel Buses in Morocco

The heavy reliance on petroleum-based fuels in the road transport industry, especially public transportation, results in substantial emissions of greenhouse gases. A significant obstacle on the path to a more sustainable public transportation sector is the employment of alternative fuels with lower environmental implications. Although there are several in-depth well-to-wheel studies for developed countries, extrapolating those results to gasoline markets in developing countries presents challenges because of significant differences in local fuel conditions and vehicle engine technologies. Notably, this study provides a national-level environmental life cycle assessment of alternative buses in Morocco and compares current diesel buses to potential hybrid diesel-electric buses, battery-electric buses, and fuel-cell buses from a well-to-wheel perspective. The model and approach used in this study applies to other countries with developing economies. Total energy consumption broken out by fuel type, greenhouse gas emissions, and criterion air pollutants is the primary outcome of this investigation. Findings highlight an energy cut of 44.7% from battery-electric buses, 36.3% from fuel-cell buses, and 31.7% from hybrid buses with regard to the current diesel buses. Additionally, alternative fuel buses proved to be less polluting in terms of greenhouse gas emissions with 50.8% less from battery-electric buses, 46.7% less from fuel-cell buses, and 26.8% less from hybrid buses; consequently, this would lead to reduced climate change, air pollution, acidification, and eutrophication, given the Egalitarian Environmental Impact Assessment. Ultimately, Morocco will have to tackle technological, financial, and institutional barriers to fully implement the change by 2030.

Fire safety of interior materials of buses

AbstractThis study provides an analysis on the fire safety of passengers and the fire protection of coaches and buses. A brief review of major bus fire incidents, an overview of current regulations in Europe, and their limitations are presented. The study finds that the current small‐scale fire test methods described in UN ECE Reg No. 118 need to be replaced by test methods that can assess the reaction to fire of materials when exposed to ignition sources of varying sizes. To address these shortcomings, the study proposed an expert recommendation to update the material fire safety requirements and testing for buses. Additional measures are proposed, derived from objectives and strategies applied in other transport sectors, and can be tested through existing European and international standards, which are widely used by several industries. These measures aim to extend the time with tenable conditions for a safe evacuation in case of fire, reduce the degree of damage to buses, reduce the risk for fast and excessive thermal exposure on modern energy carriers needed for a more sustainable transport sector.

Evaluating green productivity of the regional transport sector in South Asia considering environmental and safety constraints: the evolution from static and dynamic perspectives.

The assessment of green productivity not only establishes the production ability but also involves economic, environmental, and social aspects which are the ultimate goals in achieving the sustainability. In this context, unlike the majority of previous literature, we have simultaneously considered the environmental and safety aspects to measure the static and dynamic evolution of green productivity to achieve a safe, eco-friendly, and sustainable development of the regional transport sector in South Asia. First, we proposed the super-efficiency ray-slack-based measure model with undesirable output to assess the static efficiency, which can effectively characterize weak and strong disposability relationship between desirable and undesirable outputs. Second, the biennial Malmquist-Luenberger index has been adopted to examine the dynamic efficiency, which can overcome recalculation issue once an additional time period is included in the data. Therefore, the proposed methodology provides more comprehensive, robust, and reliable insight in comparison to the conventional models. The results indicate (i) both static and dynamic efficiencies decreased during 2000-2019, implying that the transport sector in South Asia follows an unsustainable green development path at the regional level; (ii) dynamic efficiency was primarily held back by green technological innovation whereas green technical efficiency had a modest positive contribution. The policy implications suggest effective ways to improve green productivity of the transport sector in South Asia by promoting coordinated development among the transport structure, environmental and safety aspects, strengthening advance and innovative production technologies, endorsing green transportation practices, and implementing safety regulations and emission standards for the sustainable transport sector.

Evaluating Biofuel Energy Policies for Sustainable Transportation Sector: A System Dynamics Approach

Energy is vital for techno-socio-economic development of global transportation sector. A country’s energy policy will aim to provide an appropriate mix of resources to meet its energy demand. Biofuels have emerged as an alternative to meet the energy requirements. The contribution of this study is the evaluation of sustainable biofuel energy policies to increase the usage of biofuels in the transport sector without affecting the country's food security and to achieve social, economic and environmental benefits. The successful implementation of complex relationship between the factors influencing the production and use of biofuels is also addressed. In the present work, a system dynamics model has been developed to evaluate biofuel production focusing food security and to assess its impact on the economy and the environment. Simulation results have shown that the maximum biodiesel blending between 3.03% to 11.01% is possible without impacting the food security. It has been noted that 20% or less of biodiesel blends can be used as direct replacements for diesel fuel in all heavy-duty diesel vehicles without any alteration or modification of their engines. It has been demonstrated that biofuel blending strategies have a positive impact on the reduction of CO2 emission in the Indian transport sector.

Implementation of COVID-19 measures in railway operation in the Slovak Republic

Rail transport has a crucial role to play not only in the EU’s strategy for a sustainable transport sector, but also in terms of economic and social cohesion. It contributes significantly to the mix of transport modes in the EU, while providing clean mobility and a high degree of efficiency. Following the outbreak of the COVID-19 pandemic, the volume of passenger and freight rail transport has fallen sharply due to constraints and lower demand for transport. Several players in the rail market had to close down. Rail operators had to face a sharp decline in transport services. In 2020, the demand for passenger transport was significantly lower than in the previous year. Thus, railway undertakings were not able to pay the charges for access to the railway infrastructure during the emergency caused by the COVID-19 pandemic. Infrastructure managers had the opportunity to temporarily reduce, waive or defer these charges. The negative economic consequences of the COVID-19 pandemic could reduce or significantly endanger their financial viability for market stakeholders. Reducing charges for access to railway infrastructure is just one of the few measures that will help railway undertakings to function better. The paper focuses on the analysis of the impact of the pandemic and the implemented measures on the passenger rail sector in the Slovak Republic and on the development of rail passenger and freight transport during the pandemic. It summarizes the proposed measures against the spread of the COVID-19 pandemic in rail transport in Slovakia.