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    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
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    <item>
      <title>Assessing public receptivity and preference formation in the transition to fully autonomous vehicles</title>
      <link>https://trid.trb.org/View/2635962</link>
      <description><![CDATA[Fully autonomous vehicles (FAVs) are expected to reshape transportation systems and benefit society in several ways, but their advantages do not guarantee that the public will embrace them, a factor that is critical to their widespread deployment. This local pilot case study in Arlington, Texas (N = 295) aimed to supplement the existing literature on the adoption of autonomous vehicles (AVs) by investigating how the public’s perceptions shift as the level of autonomy increases. A survey questionnaire was developed to examine how demographic and attitudinal factors influence automation preference rankings and non-parametric statistical tests were used to evaluate the responses. The findings indicated significant variations in ranking preferences, with an overall preference for manual vehicles, followed by partially autonomous vehicles and FAVs. Among different demographic groups, age, gender, race, and prior exposure to AVs were found to be significant for ranking manual vehicles and FAVs. Spearman’s rank correlation analysis revealed a mirrored and opposite trend across attitudinal factors for rankings of manual vehicles and FAVs, but preferences for partial automation were not strongly influenced by them. This study highlights the importance of public receptivity to FAVs and may benefit policymakers by providing insight into the factors that affect the perceptions of prospective users, thereby facilitating their integration onto existing roadways.]]></description>
      <pubDate>Wed, 11 Mar 2026 14:45:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/2635962</guid>
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    <item>
      <title>Hydrogen as an aviation fuel: Safety concerns and mitigation strategies</title>
      <link>https://trid.trb.org/View/2628244</link>
      <description><![CDATA[The aviation industry is gradually transitioning towards net zero carbon emissions by addressing its primary source of emissions: aircraft fuel. Among alternative fuels, hydrogen has emerged as a promising solution, offering strong potential to support net zero targets while remaining viable for use in aircraft engines. However, it is imperative to understand its safety challenges and mitigation strategies to ensure this transition occurs safely. Despite growing research on hydrogen in aviation, few studies have focused specifically on hydrogen safety. This study addresses that gap by systematically synthesising both risks and mitigation strategies from publications spanning 2015, when hydrogen safety research began to accelerate, through to 2025, providing a comprehensive overview of current knowledge on hydrogen fuel safety in aviation. Our findings highlight key risks associated with hydrogen storage, leakage, flammability, and material compatibility, while also noting emerging strategies in hydrogen storage and handling. This includes advanced leak detection systems to manage leakage risks, boil off recovery technologies to address hydrogen loss during refuelling, improved insulation for cryogenic tanks to reduce heat transfer, and pressure build up. Reviewing these areas clarifies what is known, identifies where further work is needed, and provides practical recommendations for academics and industry stakeholders. We recommend future research to refine risk assessment models to account for hazards such as boil off gas venting, leakage during refuelling, and the spatial and operational interactions that arise with hydrogen and kerosene fuelled aircraft operate in proximity, including their implications for safety exclusion zones and ground handling.]]></description>
      <pubDate>Thu, 26 Feb 2026 14:51:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/2628244</guid>
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    <item>
      <title>Investments in local public transport: A systematic literature review on evaluation methods with a focus on the role of uncertainty</title>
      <link>https://trid.trb.org/View/2628243</link>
      <description><![CDATA[This paper presents a systematic literature review for Local Public Transport (LPT) investment evaluation, with a particular focus on how uncertainty is addressed. It identifies the main methodological approaches – such as classic Discounted Cash Flows (DCF) methods, Cost-Benefit Analysis (CBA), Total Cost of Ownership (TCO), Life Cycle Costing (LCC), and constrained optimization models – and examines their underlying assumptions, cost structures, and degrees of complexity. The review also maps the most frequently adopted evaluation variables across economic, environmental, technical, and infrastructural domains. Particular attention is devoted to how recent studies incorporate uncertainty, through tools such as scenario analysis, sensitivity testing, Monte Carlo simulation, and Real Option Analysis (ROA). Beyond methods and variables, the paper analyses the evolving objectives of LPT investment studies, tracing the shift from a narrow focus on financial efficiency toward broader goals such as decarbonization, social inclusion, and infrastructure resilience. By combining methodological classification with thematic analysis, this work provides a comprehensive overview of the analytical evolution in LPT appraisal and highlights areas for future research. The review highlights that, despite the LPT sector undergoing ecological transition, digitalization, and broader technological evolution in a context of high uncertainty, most studies still rely on static and deterministic methods. This gap limits the ability of current evaluations to address volatility and guide effective investment decisions under uncertainty.]]></description>
      <pubDate>Thu, 26 Feb 2026 14:51:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/2628243</guid>
    </item>
    <item>
      <title>The impact of airport openings on corporate innovation: Evidence from China</title>
      <link>https://trid.trb.org/View/2628242</link>
      <description><![CDATA[The establishment of airports injects economic vitality into regions and catalyzes for corporate innovation. Drawing on panel data on corporate patent acquisitions in China from 2010 to 2022, this study employs a time-varying difference-in-differences (DID) approach to empirically assess the impact of airport openings on corporate innovation and its underlying mechanisms. The results reveal that the opening of airports significantly enhances the patent output of local firms, primarily through attracting high-skilled talent and facilitating industrial upgrading. Furthermore, the effects exhibit notable heterogeneity across regions and firm characteristics. These findings highlight the pivotal role of airport infrastructure in fostering innovation-driven regional economic development.]]></description>
      <pubDate>Thu, 26 Feb 2026 14:51:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/2628242</guid>
    </item>
    <item>
      <title>Maritime service network design with oil-fueled and LNG-fueled mixed vessel fleet under uncertainty: Overview and future research directions</title>
      <link>https://trid.trb.org/View/2612940</link>
      <description><![CDATA[The adoption of Liquefied Natural Gas (LNG) as an alternative fuel for vessels is a critical path to realizing the strategy of shipping decarbonization. Against the backdrop of the increasing promotion of LNG-fueled vessels, the maritime fleet of the shipping company will comprise a mixed fleet of conventional oil-fueled and LNG-fueled vessels in the mid- and long-term. Due to unpredictable trade fluctuations (e.g., the financial crisis), war, global public health emergencies (e.g., the COVID-19 pandemic), and the inherent characteristics of LNG evaporation, the maritime service network design for a mixed vessel fleet typically faces high uncertainty. This paper aims to review the literature on maritime service network design for mixed vessel fleet under uncertainty, including the problems of LNG fleet renewal, LNG bunkering station location, LNG maritime inventory routing, and the collaborative optimization of bunkering location and vessel deployment. The results remark that the following research gaps have not been well addressed: (1) The traditional fleet renewal problem has not considered the impact of government involvement on the fleet renewal decisions, and they have not measured the effects of deferring or implementing earlier of the renewal decision on shipping companies’ revenues; (2) Few studies have addressed the LNG bunkering location and vessel routing problem under uncertainty; (3) There is a lack of research on the dynamic inventory-routing problem, and the existing model formulation and solving techniques are not suitable for large-scale instances; (4) The existing collaborative optimization problems for the location-inventory and vessel deployment are mainly concentrated on the homogeneous vehicle fleet or vessel fleet, and they have not introduced uncertainty into the optimization problems. Finally, we discuss the future directions that we believe are especially important for addressing the aforementioned research gaps. Our research outcomes can help expand the theoretical research of maritime service network design and offer essential research directions for promoting the sustainable development of the port and maritime industries.]]></description>
      <pubDate>Wed, 14 Jan 2026 17:40:22 GMT</pubDate>
      <guid>https://trid.trb.org/View/2612940</guid>
    </item>
    <item>
      <title>Exploring the effects of space weather-caused satellite navigation failure on fuel consumption and aircraft emissions: A simulated study</title>
      <link>https://trid.trb.org/View/2612939</link>
      <description><![CDATA[Satellite navigation provides aircraft with precise positioning and navigation services. However, space weather can induce ionospheric irregularities and elevate the total electron content in the ionosphere, causing satellite navigation failure. Consequently, aircraft will navigate using ground aids and be disabled to fly along Great Circle Routes, increasing flight distance, fuel consumption, and aircraft emissions. To explore the effects of satellite navigation failure on flight operation, this study simulates satellite navigation failure scenarios and proposes Air Traffic Management (ATM) solutions. Specifically, the first step designs the ground aid-based shortest path using the Dijkstra algorithm, followed by the calculations of fuel consumption and aircraft emissions using the Base of Aircraft Data (BADA) and the aircraft Engine Emissions Databank (EEDB), respectively. Based on the collected 11,037 U.S. flight plans on 5 February 2024 (UTC), simulations show that a single-day satellite navigation failure can result in an increase of flight distances by 2,371,777 km, fuel consumption of 7176 tons, and CO₂ emission of 22,604 tons. While this study focuses on simulations in the U.S., the findings have a broad implication and can serve as a framework to address space weather effects on aviation in other regions of the world.]]></description>
      <pubDate>Wed, 14 Jan 2026 17:40:22 GMT</pubDate>
      <guid>https://trid.trb.org/View/2612939</guid>
    </item>
    <item>
      <title>Mapping reverse logistics: Research insights, environmental impacts, and pathways to sustainability</title>
      <link>https://trid.trb.org/View/2612938</link>
      <description><![CDATA[Reverse logistics, involving the return, recycling, and repurposing of products, is increasingly recognized not only as an environmental imperative but also as a critical field within economics and management. This study conducts a bibliometric analysis of 3085 documents from Scopus to investigate how reverse logistics has evolved in business, management, and economics research. By employing performance analysis and science mapping, the study identifies key publication trends, influential authors and institutions, and thematic clusters with a particular focus on cost efficiency, supply chain decision-making, and strategic management. The findings highlight the growing role of reverse logistics in achieving competitive advantage, enhancing ESG performance, and supporting circular economy models. By narrowing its lens to the economics and management perspective, this review provides a roadmap for scholars and practitioners to integrate reverse logistics into sustainable business strategies, thereby aligning with the journal’s scope and contributing to the advancement of management research.]]></description>
      <pubDate>Wed, 14 Jan 2026 17:40:22 GMT</pubDate>
      <guid>https://trid.trb.org/View/2612938</guid>
    </item>
    <item>
      <title>Econometric modeling of route-level market share dynamics in Nigeria’s domestic airline sector</title>
      <link>https://trid.trb.org/View/2611064</link>
      <description><![CDATA[This study investigates the determinants of route-level market share dynamics in Nigeria’s domestic airline sector using quarterly panel data from 2005 to 2023. Employing cointegration and error correction models (ECM), supported by robustness checks with VAR and VECM, the analysis evaluates the long- and short-run impacts of fare levels, competition, flight frequency, and passenger volumes on airline market share. The results show that fare has limited explanatory power, while frequency, passenger demand, and competitive intensity are the primary drivers of market share. Short-run fluctuations are rapidly corrected, with approximately 60 % of deviations from equilibrium adjusted each period. These findings align with Nigeria's aviation history, where fare undercutting strategies contributed to the collapse of carriers such as Arik and Bellview. At the same time, service frequency and reliability underpinned the rise of dominant airlines like Air Peace and Ibom Air. Comparative evidence from India, Brazil, and Indonesia further confirms that in deregulated but infrastructure-constrained markets, frequency and network expansion consistently outweigh fare competition. The study contributes empirically by offering one of the few route-level econometric analyses of Africa's domestic airline markets, theoretically by situating frequency effects and demand theory, and practically by providing policy guidance. Findings include prioritizing operational reliability over fare wars, strengthening financial oversight to reduce unsustainable competition, and leveraging the Single African Air Transport Market (SAATM) to scale Nigerian carriers regionally. Overall, the results underscore that market share alone is insufficient for sustainability; profitability, efficiency, and strategic expansion must complement market presence to ensure the long-term viability of Nigerian airlines.]]></description>
      <pubDate>Wed, 14 Jan 2026 17:40:22 GMT</pubDate>
      <guid>https://trid.trb.org/View/2611064</guid>
    </item>
    <item>
      <title>A hybrid cost model for light and heavy metro services</title>
      <link>https://trid.trb.org/View/2608034</link>
      <description><![CDATA[We develop a hybrid cost model to estimate the standard cost of light metro (LM) and heavy metro (HM) services, incorporating key technological factors such as degree of automation, wheel technology, and peak hourly capacity. The analysis draws on economic and transport data covering the entire universe of metro revenue kilometers operated in Italian cities in 2017. Our results show that cost structures vary substantially with the underlying technology. HM services are more capital-intensive due to higher train depreciation and associated capital costs compared to LM services. As a result, while HM services exhibit higher costs per kilometer, they are more cost-efficient on a per seat-km basis due to greater capacity. This implies that significant investments in high-capacity metro systems are economically justified only when demand levels are sufficiently high. A sensitivity analysis shows that standard unit costs decrease with improvements in train and driver productivity, and that gains in infrastructure maintenance efficiency have a stronger impact than those in train maintenance. Also scale economies play a role, as unit costs decline with increasing service size. Additionally, extending station opening hours results in higher costs that local authorities may choose to bear to enhance service quality. These findings can inform the definition of maximum economic compensation (i.e., the auction base) in competitive tendering procedures, or serve as a benchmark in negotiations with local monopolistic operators.]]></description>
      <pubDate>Mon, 29 Dec 2025 09:33:39 GMT</pubDate>
      <guid>https://trid.trb.org/View/2608034</guid>
    </item>
    <item>
      <title>Harnessing digital twin technology for enhanced aircraft turnaround efficiency</title>
      <link>https://trid.trb.org/View/2601477</link>
      <description><![CDATA[The aircraft turnaround operation is a critical component of air transportation, traditionally carried out using manually coordinated devices. Consequently, the operational efficiency is often constrained by the volume of labor and individual capabilities. To address this, some airports are exploring the potential of automated turnaround operations, where flights are serviced by newly designed smart devices. This study proposes a unique method for predicting the efficiency of automated turnaround operations using a digital-twin model. First, we designed a sandbox-based apron to simulate the physical environment, as no automated apron currently exists. Next, we applied network planning technique to establish coordinated operation rules among the smart devices, creating an optimized procedure for aircraft automated turnaround operation. Our results indicate that, compared to the statistical efficiency of manual-device coordinated operations, the time required for an automated turnaround operation for a single flight can be reduced by approximately 24.53 %.]]></description>
      <pubDate>Mon, 22 Dec 2025 16:07:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/2601477</guid>
    </item>
    <item>
      <title>Meteorological impacts on aviation carbon emissions during takeoff and landing at 25 major global airports</title>
      <link>https://trid.trb.org/View/2603871</link>
      <description><![CDATA[Aviation plays a pivotal role in facilitating global economic integration, yet its associated greenhouse gas emissions and climate impacts have garnered increasing scrutiny. This study examined how meteorological conditions affect aircraft carbon emissions during the landing and takeoff (LTO) cycle, focusing on the world’s 25 busiest international airports in 2019. We integrated flight level emissions with high-resolution ERA5 reanalysis data and estimated a fixed effects panel model to quantify the effects of temperature, wind speed, atmospheric pressure, cloud base height, low-level cloud cover, precipitation, and snow cover on emissions intensity. The results indicate that meteorological factors exert statistically significant and heterogeneous impacts across flight phases. Specifically, higher temperatures, lower atmospheric pressure, reduced cloud base height, and intense precipitation or snow cover are associated with increased per-flight carbon emissions, with particularly pronounced effects during taxiing operations. Sensitivity also varied across climate zones, airport infrastructure, and operating procedures, underscoring substantial spatial heterogeneity. These findings support the design of weather adaptive operating strategies and decarbonization pathways in aviation and provide a more nuanced understanding of weather driven variability in emissions.]]></description>
      <pubDate>Mon, 22 Dec 2025 16:07:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/2603871</guid>
    </item>
    <item>
      <title>The Service Network Fleet Transition Problem</title>
      <link>https://trid.trb.org/View/2596737</link>
      <description><![CDATA[The road freight sector is a large source of carbon emissions yet notoriously hard to decarbonize. Logistics service providers and fleet operators face increasing pressure to adopt and implement carbon emissions reduction targets over the next years and decades. However, they lack appropriate tools to design and evaluate fleet transition strategies amidst competing technology alternatives, and the complexity of spatial and temporal cost differentials, along with intermediate emissions reduction goals. To address this, we introduce the Service Network Fleet Transition Problem to guide and facilitate companies’ transitions towards low-carbon vehicle fleets and operations. We propose an efficient integer linear programming formulation to model and solve the problem, capturing critical real-world constraints such as fueling and charging infrastructure requirements and the geo-spatial characteristics of service networks. We demonstrate the applicability of our formulation to real-world fleet and network data of a large U.S. consumer packaged goods company and provide extensive analyses and managerial insights for varying cost parameters and decarbonization strategies.]]></description>
      <pubDate>Mon, 24 Nov 2025 10:22:53 GMT</pubDate>
      <guid>https://trid.trb.org/View/2596737</guid>
    </item>
    <item>
      <title>On the packaging of infrastructure projects in a competitive bidding environment</title>
      <link>https://trid.trb.org/View/2593979</link>
      <description><![CDATA[Theory predicts that bundling should dominate unbundling in transportation infrastructure procurement contracts, yet in practice unbundling is common. We present a model with equilibria where unbundling is superior to bundling, with competitive bidding between many firms to obtain the different contracts, and two layers of private information: Firms have low or high building costs, and builders have private information on infrastructure quality. When this information cannot be inferred by other firms, good builders can outbid others during the operation auction and anticipate positive expected payoffs. Bidding for a bundled project, however, may erase the winner’s profit, yielding a worse outcome than under unbundling.]]></description>
      <pubDate>Tue, 18 Nov 2025 11:04:19 GMT</pubDate>
      <guid>https://trid.trb.org/View/2593979</guid>
    </item>
    <item>
      <title>Effect of privatizing Japanese expressway companies on maintenance and management efficiency</title>
      <link>https://trid.trb.org/View/2583082</link>
      <description><![CDATA[In 2005, Japan privatized its four public highway corporations, resulting in the establishment of three NEXCO companies. Although these entities remain fully government-owned, future stock exchange listing is envisioned. To inform discussions on this transition, it is essential to analyze the effects of privatization on management efficiency and identify factors influencing efficiency changes. While a certain degree of progress has been observed in achieving the three objectives articulated by the Japanese government at the time of privatization—namely, the steady repayment of interest-bearing debt, the early and inexpensive construction of expressways, and the provision of various services—these initial goals did not encompass maintenance and operation, which have become increasingly important over time. As a result, the impact of privatization on these aspects remains insufficiently examined. This study therefore focuses on existing expressway segments and investigates changes in maintenance and operational efficiency before and after privatization. Using data envelopment analysis (DEA), the authors evaluate efficiency based on indicators such as management costs and toll revenue, comparing performance in the pre-privatization period, immediately after privatization, and 14 years later. The results indicate that network-wide efficiency showed little change immediately after privatization. However, route-level analysis reveals a decline in efficiency over time. These findings suggest that privatization, even in the form of a joint stock company, may have limited capacity to enhance long-term management efficiency in expressway operations.]]></description>
      <pubDate>Mon, 22 Sep 2025 08:49:24 GMT</pubDate>
      <guid>https://trid.trb.org/View/2583082</guid>
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    <item>
      <title>Measuring airports’ ability to sustain the COVID-19 disruption in the Chinese domestic market: Considering the effect of low-cost carriers and high-speed rails</title>
      <link>https://trid.trb.org/View/2583043</link>
      <description><![CDATA[Air transportation continues to gain focus and grow rapidly to meet the demand for social development. Meanwhile, the risk of unpredictable disruptive events like the COVID-19 pandemic must be addressed to ensure stable air transportation. The Chinese domestic market was experiencing unique challenges during the pandemic, considering strict pandemic control measures, limited deregulation, and significant competition from high-speed rail (HSR). This study evaluates the determinants of Chinese airports' performance from 2020 to 2022 based on a weighted connectivity index and an interactive fixed effect (IFE) model. The authors highlight the critical role of low-cost carriers (LCCs) in mitigating the pandemic's impact, with LCC route entry demonstrating a more pronounced positive effect on airport performance than increased flight frequency. Contrary to conventional expectations, HSR availability did not significantly undermine airport performance, suggesting a more complex air-HSR relationship shaped by intermodal cooperation and regional travel behaviour. Geographical heterogeneity also played a significant role: while LCC entry was vital in the less-developed western regions, increased frequency of LCC flights contributed more to the stable and mature eastern markets. These findings underscore the importance of fostering LCC development and promoting air-HSR coordination. Overall, this study provides valuable insights for policymakers and industry stakeholders to enhance the resilience of the aviation sector in the post-COVID-19 era.]]></description>
      <pubDate>Fri, 19 Sep 2025 16:58:07 GMT</pubDate>
      <guid>https://trid.trb.org/View/2583043</guid>
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