Search Results (4,174)

The social potential of Urban Air Mobility (UAM) as a greener and faster transportation system in and around urban environments is indisputable. Nevertheless, the success of UAM introduction and its wide use will strongly depend on acceptance by the citizens and future UAM users. The impact on overall quality of life, as a multidimensional concept that encompasses physical health, mental and emotional well-being, economic status, education, and the environment, is becoming a significant issue. This paper aims to describe the performance framework for the assessment of the social and environmental impact of UAM. The specific objectives are to identify the full range of UAM’s impacts on citizens’ quality of life and to propose a set of indicators that enables the quantification and assessment of the identified impacts. Firstly, the main issues (focus areas) were identified, namely, noise, visual pollution, and privacy concerns, followed by access and equity, economic aspect, emissions, public safety, and impact on wildlife. In the next step, for each identified focus area, performance indicators were defined along with the several cross-cutting areas for a geographical, temporal, demographic, socioeconomic, and behavioral resolution. The proposed performance framework could enable more efficient mitigation measures and possibly contribute to wider adoption of the UAM operations. Full article

In the urban public transport network, the transfer of buses and subways provides convenience for residents to travel efficiently. But in actual operation, it is found that accidents, natural disasters, and other damage are inevitable. These sudden events may lead to route suspensions and service delays, ultimately resulting in network paralysis. In this paper, complex network theory is used to construct a weighted double-layer network model. Carrying capacity is considered the edge weight. The model analyzes the impact of these sudden events on network performance. It also conducts in-depth research on network structure and node importance. A collective influence (CI) algorithm is proposed as a centrality index to evaluate node importance. Based on the dynamic nature of the attacks, the network state is divided into initial network and current network. Taking Hohhot as an example, the results show that the network based on a CI algorithm node attack has the worst invulnerability. The network invulnerability based on an edge weight attack is better than that of edge betweenness. Compared with the current network, the invulnerability of the initial network is stronger. This indicates that ongoing changes and adaptations in the network may accelerate the decline in overall performance. At the same time, targeted interventions on key nodes and edges can enhance the network’s invulnerability. Planners can continuously monitor network performance to provide a basis for dynamic management and real-time adjustments. Additionally, effective information about critical routes to the public helps ensure the sustainable operation of the public transportation network. Full article

Background: Manganese is an essential micronutrient that plays a pivotal role in environmental systems, plant physiology, and human health. This review comprehensively examines the manganese cycle in the environment, its absorption and transport mechanisms in plants, and the implications of manganese exposure to human health. Objectives: The objectives of this review are to (i) analyze the environmental cycling of manganese and its bioavailability, (ii) evaluate the role of manganese in plant metabolism and disease resistance, and (iii) assess the impact of manganese toxicity and deficiency on human health. Conclusion: This review highlights that while manganese is crucial for photosynthesis, enzyme activation, and resistance to plant diseases, both its deficiency and toxicity can have severe consequences. In plants, manganese deficiency can lead to impaired growth and reduced crop yields, while toxicity, particularly in acidic soils, can inhibit photosynthesis and stunt development. In humans, manganese is necessary for various physiological processes, but overexposure, especially in occupational settings, can result in neurodegenerative conditions such as manganism. The conclusion emphasizes the importance of managing manganese levels in agriculture and industry to optimize its benefits while minimizing health risks. A multidisciplinary approach is advocated to enhance agricultural productivity and ensure public health safety. Full article

In addition to addressing the labor shortage due to an aging population, the transition to autonomous vehicle (AV)-based mobility services offers enhanced efficiency and operational flexibility for public transportation. However, much of the existing focus has been on improving AV safety without fully considering road conditions and real-world service demand. This study contributes to the literature by proposing a comprehensive framework for efficiently integrating AV-based mobility services at the network level, addressing these gaps. The framework analyzes and optimizes service networks by incorporating actual demand patterns, quantifying road segment difficulty from an AV perspective, and developing an optimization model based on these factors. The framework begins by quantifying the operational difficulty of road segments through an evaluation of Operational Design Domains (ODDs), providing a precise measure of AV suitability under varying road conditions. It then introduces a quantitative metric to assess operational feasibility, considering factors such as the service margin, costs, and safety risks. Using these metrics alongside Genetic Algorithms (GAs), the framework identifies an optimal service network that balances safety, efficiency, and profitability. By analyzing real-world data from different mobility services, such as taxis, Demand-Responsive Transport (DRT), and Special Transportation Services (STSs), this study highlights the need for service-specific strategies to optimize AV deployment. The findings show that optimal networks vary with demand patterns and road difficulty, demonstrating the importance of tailored network designs. This research provides a scalable, data-driven approach for integrating AV services into public transportation systems and lays the foundation for further improvements by incorporating dynamic factors and broader urban contexts. Full article

The concept of the “x-minute city” emphasises connected, mixed-use, and functionally dense urban areas where residents can access most daily necessities within a short walk or bike ride. By promoting proximity to essential destinations and sustainable transport options, this approach reduces the need for extensive travel and minimises environmental impact. This paper analyses the readiness of cities to function as x-minute cities and identifies necessary interventions. Using a reproducible and scalable methodology based on open data and software, the study assesses the accessibility of key urban amenities within specified timeframes. Cumulative accessibility metrics are calculated for different destination categories, considering both walking and cycling. In the case of Seville, accessibility requirements outlined in policy documents are already met for many essential services, particularly public facilities. The study identifies neighbourhoods that excel in accessibility and others that require improvement in adhering to x-minute city principles. The methodology and findings can inform planning and policy decisions in other cities, guiding efforts to enhance amenity provision, test accessibility scenarios, and target intervention areas. Full article

The connected and automated vehicles (CAVs) that are expected to be increasingly common on U.S. roads in the coming decades offer potential benefits in safety, efficiency, and mobility; they also raise concerns related to equity, access, and impacts on land use and travel behavior, as well as questions about extensive data requirements for CAVs to communicate with other vehicles and the environment in order to operate safely and efficiently. We report on interviews with North Carolina transportation experts about CAVs and their implications for sustainable transportation that serves all travelers with affordable, safe, and dignified mobility that also produces fewer environment impacts (emissions to air, water, and land; resource consumption; land use changes). The data reveal great interest among transportation professionals about a CAV transition, but a lack of consensus on the state of play and necessary next steps. Concerns include impacts on planning practice; implications for land use, equity, and safety; and data security and privacy. The findings suggest that local, regional, and state agencies would benefit from clear technical guidance on how to prepare for CAVs and to engage with the public, given high interest about a coming CAV transition. Intense data requirements for CAVs and associated infrastructure, as well as the regulatory and policy tools that will be required, raise concerns about threats to data safety and security and argue for proactive action. Full article

The increasing frequency and severity of climate variability poses substantial challenges to the sustainability and reliability of transportation infrastructure worldwide. Transportation systems, vital to economic and social activities, are highly vulnerable to extreme weather, sea-level rise, and temperature fluctuations, which can disrupt their structural integrity, operational efficiency, and maintenance needs. The aim of this study is to explore the scholarly landscape concerning the effects of climate variability on transportation systems, analyzing 23 years of scientific publications to assess research trends. Utilizing bibliometric methods, this analysis synthesizes data from numerous scientific publications to identify key trends, research hotspots, influential authors, and collaborative networks within this domain. This study highlights the growing acknowledgment of climate variability as a crucial factor affecting the design, maintenance, and operational resilience of transportation infrastructure. Key findings indicate a notable increase in research over the last decade, with a strong focus on the effects of extreme weather events, sea-level rise, and temperature changes. The analysis also shows a multidisciplinary approach, incorporating perspectives from civil engineering, environmental science, and policy studies. This comprehensive overview serves as a foundational resource for researchers and policymakers, aiming to enhance the adaptive capacity of transportation systems to climate variability through informed decision-making and strategic planning. Full article

(1) Background: Public transport has a vital role to play in creating sustainable, accessible societies. Accessible and inclusive, door-to-door public transport systems with low barriers to use benefit everyone, increasing the mobility of citizens and improving independence. As the industry strives towards multi-modal and Mobility as a Service (MaaS) concepts, there is a need to delve deep into the needs and perceptions of transport user’s door-to-door journeys to find ways to improve. Accordingly, in order to increase the sustainability of MaaS, improving accessibility and understanding service user perceptions are of utmost importance. However, there is a scarcity of research within national transport services to determine unmet user needs to increase the accessibility and autonomy of door-to-door journeys. This research aims to investigate if it is possible to improve the door-to-door journey experience for public transport travellers, increasing the accessibility and the perception of autonomy via technology, and by doing so, providing a more sustainable alternative to road transport. It focuses on understanding service users of Ireland’s National Rail service, Irish Rail, to create key improvements in interactive systems. (2) Methods: The study applies a user-centred mixed-methods methodology using surveys (N = 316) and co-design workshops (four workshops N = 15). The research collected deep insights into the mindsets and needs of service users, showing the potential to improve this door-to-the-door customer journey. Key improvements for interactive systems were outlined. Experience maps were designed, leading to a Conceptual Design for a travel assistant to aid the service user throughout the door-to-door journey. (3) Results: Travellers’ autonomy and the sense of freedom they experience can be improved, mainly if their needs across the complete door-to-door customer journey are supported. Highlighted areas for action include information, accessibility, personal security, ticketing, comfort, facilities, and anxiety. (4) Conclusions: This research reiterates the need for national transport and MaaS providers to prioritise service users’ perspectives when developing sustainable services. Co-designing is recommended as a means of achieving this. Full article

Durban Port in South Africa is the largest container port and the busiest shipping terminal in sub-Saharan Africa. Approximately 60% of the country’s containerised cargo and 40% of break-bulk cargo transit through Durban. The port is near the central business district, which has a positive spin-off in terms of tourism, recreation, and accessibility to transport and other business activities. The juxtaposition of industry, the port, and the community has resulted in sustained public health implications, a relic of the apartheid era. Like most ports in Africa, Durban Port lacks proper quantification of emissions from marine mobile sources. This study is aimed at estimating atmospheric emissions from ocean-going vessels (OGVs) in and around Durban Port for a period of one year from 1 January 2018 to 31 December 2018 using a mid-tier (activity-based) approach to supplement existing understandings of emissions from local industries. Emission estimates were then inputted to the AERMOD atmospheric dispersion model to allow for a comparison between ambient concentrations and national ambient air quality standards to assess potential health impacts. The study is an advancement in understanding the impact of mobile sources, particularly shipping, on air quality and health, and offers an example for other African ports to follow. Full article

With nearly 40% of the total plastics produced being used for packaging, up to five trillion plastic bags are consumed in the world annually. The inadequate disposal of plastic waste and its persistence has become a serious challenge/risk to the environment, health, and well-being of living creatures, including humans. The natural degradation of plastics is extremely slow; large pieces of plastic may break down into microplastics (MPs) (1 μm–5 mm) or nanoplastics (NPs) (<1000 nm) after protracted physical, chemical, and/or biological degradations. A brief overview of the transport of micro- and nanoplastics in the aquatic, terrestrial, and atmospheric environments is presented. Details are provided on the exposure routes for these waste materials and their entry into humans and other biota through ingestion, inhalation, and dermal contact. The greatest concern is the cumulative impact of the heterogeneous secondary MPs and NPs on planetary and human health. Inhaled MPs and NPs have been shown to affect the upper respiratory tract, lower respiratory tract, and alveoli; prolonged exposure can lead to chronic inflammatory changes and systemic disease. These can also lead to autoimmune diseases and other chronic health conditions, including atherosclerosis and malignancy. Sustainable mitigation strategies to reduce the impact of MPs/NPs include source reduction, material substitution, filtration and purification, transformation of plastic waste into value-added materials, technological innovations, etc. Multidisciplinary collaborations across the fields of medicine, public health, environmental science, economics, and policy are required to help limit the detrimental effects of widespread MPs and NPs in the environment. Full article

(1) Background: The aim of this study was to understand the factors associated with vaccine hesitancy and refusal in Indonesia using the Social–Ecological Model (SEM). (2) Methods: Data on demographics, religiosity, family dynamics, and perceptions of public health efforts were collected through an online survey and compared to the rates of vaccine hesitancy and refusal. (3) Results: Income and sex were significantly associated with vaccine hesitancy. Based on a vaccine passport policy to enter public spaces, people who felt inhibited to enter public spaces or perceived privacy threats were twice as likely to exhibit vaccine hesitancy. Participants who believed that religious groups had a difficult time getting vaccinated were nearly twice as likely to exhibit vaccine hesitancy and three times more likely to exhibit vaccine refusal. However, participants who believed in a higher religious power were 58% less likely to exhibit vaccine hesitancy. Religious leaders significantly influenced participants to make the decision regarding vaccination. Individuals with vaccine refusal were more than twice as likely to share information with others without fact-checking. Notably, structural barriers such as distance and transportation were most strongly associated with vaccine hesitancy and refusal. (4) Conclusion: Cultural factors play a significant role in vaccine hesitancy and refusal. The SEM can be used to propose multi-level interventions with collaboration and communication among stakeholders to improve community health. Full article

Container transportation has the advantages of standardization, high efficiency, and high safety, which are essential for promoting the development of the world economy and trade. Emergencies such as severe weather, public health incidents, and social security incidents can negatively affect the operational reliability of the container shipping network. To ensure the network security and high-quality operation of container shipping, a double-layer coupled container transportation network is first described to analyze the evolution of the container shipping network and the risk propagation dynamics of operation participants. On this basis, a cascade failure model of the container shipping network considering risk level is constructed. To evaluate the vulnerability of the container shipping network, the transmission mechanism of cascade failure effects of the container shipping network under different emergency development trends and the evolution law and influence path of the container shipping network structure are both analyzed. Finally, we empirically studied the container shipping network in China and the United States, and characteristic parameters of the China–U.S. container shipping network are calculated and analyzed. The model’s validity is verified through practical cases and model simulation results, and the cascading failure process of the container shipping network in China and the United States under three types of attacks is simulated. Suggestions are provided for effective improvement in the vulnerability of the container shipping network under every kind of contingency. Full article

William H. Whyte took on the challenge of assessing the amount of public space in a city based on its carrying capacity, pointing out that popular public spaces offer more room for social activities. However, the absence of qualitative characteristics makes this assessment even more challenging to implement. This study aims to find a method to gauge the carrying capacity of urban public spaces by calculating the social space ratio for pedestrian-only streets in Karlstad, Sweden, and quantifying this relationship. The social space ratio represents the proportion of public spaces that foster social interaction throughout their entire area. The method began by selecting the most relevant conceptual framework for social public spaces and then sought theory-based characteristics to assign to seven social activities on Karlstad’s pedestrian-only streets. The authors performed a comprehensive search of the literature utilizing the PRISMA approach, gathering information from credible references, placemaking toolkits, transportation toolkits, and academic sources. This was performed to determine the weighting factors and effective social areas by evaluating these activities in terms of nine categories of the chosen framework: accessibility, traffic, social infrastructure, security, places to meet, senses and experience, architecture and aesthetics, development and maintenance, and control and programming. We devised a method to calculate the carrying capacity and social space ratio of Karlstad’s pedestrian-only streets, resulting in a ratio of 0.38. The research led to the development of eight quality-control tools to analyze the seven social activities in public places. This innovative approach helps researchers and municipal planners evaluate the benefits and drawbacks of these spaces, contributing significantly to Swedish urban planning and enabling future studies to create a social area factor. Full article

Public transportation has been identified as a viable solution to mitigate traffic congestion. Transit signal priority (TSP) control, which is widely used at signalized intersections, has been recognized as a practical strategy to improve the efficiency and reliability of bus operations. However, traditional TSP control may fall short of efficiency and is facing several challenges of negative externalities for non-transit users and the need to handle conflicting priority requests. Recent studies have proposed the use of reinforcement learning (RL) methods to identify efficient traffic signal control (TSC). Some of these studies on RL-based TSC have incorporated the concept of max-pressure (MP), which is a maximal weight-matching algorithm to minimize queue sizes. Nevertheless, the existing RL-based TSC methods focus on private vehicles and cannot adequately distinguish between buses and private vehicles. In prior research, RL-based control has been implemented within the context of bus rapid transit (BRT) systems. This study proposes a novel RL-based TSC strategy that leverages the MP concept and extends it to incorporate TSP control. This is the first implementation of RL-based TSP control within the mixed-traffic road network. A significant innovation of this research is the introduction of the priority factor (PF), which is designed to prioritize bus movements at signalized intersections. The proposed RL-based TSP with PF control seeks to balance the competing objectives of enhancing bus operations while mitigating adverse impacts on non-transit users. To evaluate the performance of the proposed TSP method with the PF mechanism, simulations were conducted on an arterial and a grid network under dynamic traffic conditions. The simulation results demonstrated that the proposed TSP with PF not only reduces bus travel times and resolves conflicts between priority requests but also does not make a significant negative impact on passenger car operations. Furthermore, the PF can be dynamically assigned according to the number of passengers on each bus, suggesting the potential for the proposed approach to be applied in various traffic management scenarios. Full article

Groundwater contamination by dense nonaqueous phase liquids (DNAPLs) poses a severe environmental threat due to their persistence and toxicity. Modeling DNAPL contamination is essential for understanding their distribution, predicting contaminant spread, and developing effective remediation strategies, but it is also challenging due to their complex multiphase behavior. Over the past few decades, researchers have developed various models, including multiphase flow, mass transfer, and solute transport models, to simulate the distribution of DNAPLs. To understand the research trends in DNAPL modeling in groundwater, a bibliometric analysis was conducted using CiteSpace based on 614 publications from the WoS Core Collection database (1993–2023). The publications were statistically analyzed, and the research hotspots and trends were summarized. The statistical analysis of the publications indicates that the United States is leading the international research on DNAPL models, followed by China and Canada; the collaboration between countries and disciplines in this field needs to be strengthened. Keyword clustering and burst detection reveal that the current research hotspots focus on multiphase flow models, mass transfer models, back diffusion, and practical applications of the models; the research trends are centered on back diffusion mechanisms, the characterization of contamination source zones, and prediction of the contaminant distribution at real-world sites, as well as optimization of the remediation strategies. Full article