<rss version="2.0" xmlns:atom="https://www.w3.org/2005/Atom">
  <channel>
    <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" />
    <description></description>
    <language>en-us</language>
    <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>
    </image>
    <item>
      <title>Profiling of the Environmental Conditions for High-Altitude Pseudo Satellites Operations</title>
      <link>https://trid.trb.org/View/2627801</link>
      <description><![CDATA[High-Altitude Pseudo-Satellites (HAPS) represent a rapidly evolving segment of aerospace technology, with the majority of initiatives currently situated within a conceptual framework, designs, prototypes development or experimental stages. Given these developmental constraints combined with scenarios where direct empirical undertaking of HAPS operations is either impractical or infeasible, simulation-based approaches and advanced modelling techniques stand out as crucial segments enabling insights required for the evaluation of both endogenous system behaviours and exogenous environmental influences. Accurate representation of the environmental conditions is critical for these methodologies to yield valid and operationally relevant results. This paper, therefore, undertakes a review of profiling the environmental conditions in the context of HAPS operations, employing aircrack.io, a novel solution developed to anticipate and assess key meteorological, insolation and atmospheric conditions pertinent to the planning, operational assessment and performance evaluation of HAPS operations.]]></description>
      <pubDate>Tue, 27 Jan 2026 16:16:17 GMT</pubDate>
      <guid>https://trid.trb.org/View/2627801</guid>
    </item>
    <item>
      <title>Corrosion behavior and mechanical property degradation of Al-Zn-Mg-Cu alloy in tropical marine atmosphere</title>
      <link>https://trid.trb.org/View/2594624</link>
      <description><![CDATA[The corrosion of aluminum alloys severely impacts the long-term performance of marine infrastructure. This study aims to establish a stochastic pitting corrosion model for finite element analysis, simulating the mechanical properties under different exposure times, and to establish the correlation between corrosion behavior and mechanical property degradation of Al-Zn-Mg-Cu alloys in marine environments. Initially, a 24 months field exposure experiment was conducted in a representative marine atmospheric environment. By integrating macroscopic and microscopic corrosion morphology observations, corrosion product analysis, electrochemical testing, and mechanical property evaluations, the corrosion evolution process and underlying performance degradation mechanisms were elucidated. The results indicate that the corrosion progression of Al-Zn-Mg-Cu alloy can be categorized into three distinct stages: the initial stage (1–6 months), the intermediate stage (6–12 months), and the advanced stage (12–24 months). During the early phase, pitting corrosion is predominant, which progressively evolves into intergranular and exfoliation corrosion over time. The primary corrosion products identified are AlO(OH) and Al(OH)₃. Mechanical property tests revealed that after 24 months of corrosion, the alloy's yield strength decreased from 332.45 MPa to 307.84 MPa, tensile strength dropped from 455.60 MPa to 375.05 MPa, and elongation after fracture reduced from 18.34 % to 5.64 %. Finite element models based on corrosion pit characteristics suggest that both pit density and depth have a direct influence on the material's mechanical integrity. The simulation outcomes are consistent with experimental trends, offering theoretical insights for predicting the service performance of aluminum alloys in marine environments.]]></description>
      <pubDate>Wed, 24 Sep 2025 15:31:05 GMT</pubDate>
      <guid>https://trid.trb.org/View/2594624</guid>
    </item>
    <item>
      <title>Analysis of the aircraft performance at cruise altitude within the tropopause layer</title>
      <link>https://trid.trb.org/View/2563681</link>
      <description><![CDATA[The purpose of the current study is to examine a comprehensive analysis of aircraft performance within the tropopause layer, considering temperature anomaly occurrences at cruise flights between FL300 and FL430. Hereafter, 24 flight scenarios were analysed using 93 recorded flight data obtained from the Boeing 777F enhanced airborne flight recorder (EAFR). The methodology integrates General Electric (GE) Aviation diagnostic systems, TrueChoice and TRUEngine, and International Standard Atmosphere (ISA) data to establish relationships between temperature and altitude variations. The findings reveal significant temperature increases below the average tropopause level at 36,000 feet, resulting in elevated fuel consumption exceeding 9,000 lbs per hour. Despite moderate changes in exhaust gas temperature at 748°C, carbon dioxide emissions remain a major concern. Flights conducted above-average tropopause levels at altitudes between 390 and 430 FL indicate stability in engine parameters, ensuring optimal fuel efficiency.]]></description>
      <pubDate>Fri, 18 Jul 2025 09:06:53 GMT</pubDate>
      <guid>https://trid.trb.org/View/2563681</guid>
    </item>
    <item>
      <title>Time-dependent seismic safety assessment of aging steel bridge piers in varied atmospheric conditions</title>
      <link>https://trid.trb.org/View/2528632</link>
      <description><![CDATA[Steel bridge piers are typically considered to have good seismic performance and ductility. However, long-term exposure to atmospheric environment can lead to corrosion of the steel bridge piers, which may lead to different performance and failure modes throughout life-cycle stages. This study aims to explore the time-varying seismic performance evolution of steel bridge piers in different atmospheric environments and propose a time-varying seismic evaluation method based on performance requirements. First, a numerical simulation method for aging steel bridge piers is developed by considering the time-varying model of corrosion characteristic parameters. The degradation patterns and failure modes of steel bridge piers with varying parameters throughout their entire life-cycle in industrial and marine atmospheric environments are then analyzed. The concept of time-varying degradation ratio and aging damage index is used to quantify the effects of time-varying factors on seismic performance. Finally, formulas for predicting critical displacement values based on performance requirements are established, and a time-varying seismic performance evaluation method and process are presented. The results show that the seismic performance degradation of aging steel bridge piers caused by different service environments can reach up to 23.7 %. In addition, in the early stages of service, seismic performance of aging steel piers may be significantly reduced, with the displacement ratio for safety performance points decreasing by up to 28.6 %. Corrosion leads to more pronounced plastic deformation and stress concentration in the failure mode of aging steel piers. The aging damage index is affected by the coupling of corrosion parameters and geometric parameters. As service time progresses, the value and variability of aging damage index of steel piers increase. The accuracy of the formula for predicting time-varying critical displacement values, considering performance requirements, is validated through supplementary models and previous test results. The results underscore the importance of considering aging effect and environmental factors in the seismic performance evaluation. The proposed time-varying seismic performance evaluation method can provide reference for the life-cycle seismic design and verification of aging steel bridges.]]></description>
      <pubDate>Mon, 14 Apr 2025 17:08:11 GMT</pubDate>
      <guid>https://trid.trb.org/View/2528632</guid>
    </item>
    <item>
      <title>Calculation of X-ray Emission of Gigantic Upward Atmospheric Discharges Governed by Relativistic Runaway Electrons</title>
      <link>https://trid.trb.org/View/1784692</link>
      <description><![CDATA[On the basis of observation data on space - time characteristics of gigantic upward atmospheric discharges (UAD) there were carried out calculations of X-ray emission produced by UAD, with employing the idea of relativistic runaway electron avalanche. The results are consistent with measurements of X-ray pulses of terrestrial origin detected from satellite above mesoscale thundercloud formations.]]></description>
      <pubDate>Fri, 31 Jan 2025 17:00:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/1784692</guid>
    </item>
    <item>
      <title>EPQ-GAN: Evolutionary Perceptual Quality Assessment Generative Adversarial Network for Image Dehazing</title>
      <link>https://trid.trb.org/View/2441974</link>
      <description><![CDATA[Single image dehazing is a challenging issue with the goal to improve the quality of hazy images for computer vision applications and surveillance systems. The majority of current techniques aim to restore clear images from hazy images by approximating the transmission map and global atmospheric light. However, inaccurate estimation of these factors results in unrealistic outcomes. To overcome these challenges and to produce realistic images, the authors implemented a new approach called the Evolutionary Perceptual Quality Assessment Generative Adversarial Network (EPQ-GAN). The EPQ-GAN comprises a novel Evolutionary Generator and Discriminator. The Evolutionary training of the Generator can improve generative performance; hence, to train the Evolutionary Generator, the proposed method adopted the Differential evolution (DE) algorithm and the entire GAN network is trained with Perceptual loss from the discriminator, quality assessment loss (PSNR Loss) and adversarial loss. The proposed EPQ-GAN has superior performance compared to other state-of-the-art approaches, as evidenced by both qualitative and quantitative examination of several benchmark datasets.]]></description>
      <pubDate>Mon, 13 Jan 2025 11:12:02 GMT</pubDate>
      <guid>https://trid.trb.org/View/2441974</guid>
    </item>
    <item>
      <title>Evidence of Near-Surface Density Stratification as a Factor in Extreme Seiche Events at Ciutadella Harbor, Menorca Island</title>
      <link>https://trid.trb.org/View/2213392</link>
      <description><![CDATA[Large-amplitude harbor seiches at Ciutadella on Menorca Island in the western Mediterranean are related to local atmospheric conditions and it has been suggested that the seiche forcing mechanism involves the transfer of atmospheric energy to baroclinic modes in offshore waters. To explore this concept the authors examined the relationship between seasonal patterns of harbor seiche activity and water temperature. Results indicate that during the season of harbor water cooling, the probability of large harbor seiche activity varies linearly with water temperature. During the season of water warming, however, the probability of large seiche activity varies exponentially with the rate of water warming which is maximum at the summer solstice. These patterns in large seiche activity are in accord with published accounts and may result from seasonal changes in near-surface density stratification of the water offshore of Ciutadella.]]></description>
      <pubDate>Sat, 07 Dec 2024 10:42:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/2213392</guid>
    </item>
    <item>
      <title>Multi-Agent Reinforcement Learning for Cooperative Air Transportation Services in City-Wide Autonomous Urban Air Mobility</title>
      <link>https://trid.trb.org/View/2292401</link>
      <description><![CDATA[The development of urban-air-mobility (UAM) is rapidly progressing with spurs, and the demand for efficient transportation management systems is a rising need due to the multifaceted environmental uncertainties. Thus, this article proposes a novel air transportation service management algorithm based on multi-agent deep reinforcement learning (MADRL) to address the challenges of multi-UAM cooperation. Specifically, the proposed algorithm in this article is based on communication network (CommNet) method utilizing centralized training and distributed execution (CTDE) in multiple UAMs for providing efficient air transportation services to passengers collaboratively. Furthermore, this article adopts actual vertiport maps and UAM specifications for constructing realistic air transportation networks. By evaluating the performance of the proposed algorithm in data-intensive simulations, the results show that the proposed algorithm outperforms existing approaches in terms of air transportation service quality. Furthermore, there are no inferior UAMs by utilizing parameter sharing in CommNet and a centralized critic network in CTDE. Therefore, it can be confirmed that the research results in this article can provide a promising solution for autonomous air transportation management systems in city-wide urban areas.]]></description>
      <pubDate>Mon, 20 Nov 2023 16:25:05 GMT</pubDate>
      <guid>https://trid.trb.org/View/2292401</guid>
    </item>
    <item>
      <title>A Spatiotemporal Hybrid Model for Airspace Complexity Prediction</title>
      <link>https://trid.trb.org/View/2173254</link>
      <description><![CDATA[Airspace complexity is a key indicator that reflects the safety of airspace operations in air traffic management systems. Furthermore, to achieve efficient air traffic control, it is necessary to accurately predict the airspace complexity. In this article, the authors propose a novel spatiotemporal hybrid deep learning model for airspace complexity prediction to efficiently capture spatial correlations as well as temporal dependencies pertaining to the airspace complexity data. Specifically, the authors apply convolutional networks to discover the short-term temporal patterns and skip long short-term memory networks to model the long-term temporal patterns of airspace complexity data. Furthermore, it is observed that the graph attention network in the authors' proposed model, which emphasizes capturing the spatial correlations of the airspace sectors, can significantly improve the prediction accuracy. Extensive experiments are conducted on the real data of six airspace sectors in Southwest China. The experimental results show that the authors' spatiotemporal deep learning approach is superior to state-of-the-art methods.]]></description>
      <pubDate>Mon, 30 Oct 2023 08:53:01 GMT</pubDate>
      <guid>https://trid.trb.org/View/2173254</guid>
    </item>
    <item>
      <title>A Mooring Development and Implementation Case Study of a Government/Private Partnership</title>
      <link>https://trid.trb.org/View/2090746</link>
      <description><![CDATA[In today's world where there is an increasing need to monitor and understand the changing oceans, under flat or shrinking budgets, it is challenging for a single organization to tackle problems of this scale and magnitude alone. Engineers and scientists from the National Oceantic and Atmospheric Administration's National Data Buoy Center (NDBC) and the Monterey Bay Aquarium Research Institute (MBARI) began a collaboration with this challenge in mind. The collaboration took advantage of each organization's strengths: MBARI has the capability to rapidly develop new instrument systems, and NDBC has the infrastructure on which to test their capabilities in the field. Here, the authors present development efforts that led to the deployment of a small partial pressure of carbon dioxide (pCO₂) sensor system developed by MBARI on an NDBC buoy. The overarching goal was to demonstrate the utility of NDBC's new Auxiliary (Aux) module and determine the ease of adding third-party instrumentation to NDBC buoys. The Aux module is part of NDBC's latest generation of weather buoy data acquisition and reporting system, which provides more modularity and flexibility over previous systems. Given the large number of NDBC buoys currently in service, this capability opens up the possibility of a dense array of low-cost sensors to complement more highly specialized expensive mooring systems that are sparsely distributed. The partnership process led to the successful deployment of the pCO₂ system on NDBC buoy 46013 off Bodega Bay, California, about 48 nautical miles northwest of San Francisco, for over a year of unattended operation. The technical and scientific results are described.]]></description>
      <pubDate>Fri, 10 Feb 2023 09:02:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/2090746</guid>
    </item>
    <item>
      <title>Fine particulate pollution driven by nitrate in the moisture urban atmospheric environment in the Pearl River Delta region of south China</title>
      <link>https://trid.trb.org/View/2065230</link>
      <description><![CDATA[To identify potential sources of fine particles (PM₂.₅, with aerodynamic diameter (Dₐ) ≤ 2.5 μm) in urban Dongguan of south China, a comprehensive campaign was carried out in the whole 2019. Hourly PM₂.₅ and its dominant chemical components including organic carbon (OC), elemental carbon (EC), water-soluble inorganic ions (WSIIs) and thirteen elements were measured using online instruments. Gaseous pollutants including NH₃, HNO₃, NO₂, NO and O₃ and meteorological parameters were also synchronously measured. PM₂.₅ was dominated by carbonaceous aerosols in summer and by WSIIs in the other seasons. PM₂.₅ and its dominant chemical components mostly peaked around noon (10:00–14:00 LST). Furthermore, high PM₂.₅ levels during the daytime were closely related with the increased NO₃− levels. The high mass concentrations of NO₃− in urban Dongguan during the daytime were likely related with regional transport of NO₃− from suburban Dongguan, which was originated from the reaction between NO₂ and O₃ under the moisture condition during the nighttime. Seven major source factors for PM₂.₅ including secondary sulfate, ship emission, traffic emission, secondary nitrate, industrial processes, soil dust and coal combustion were identified by positive matrix factorization (PMF) analysis, which contributed 26 ± 14%, 16 ± 16%, 16 ± 10%, 14 ± 11%, 12 ± 11%, 8 ± 6% and 8 ± 6%, respectively, to annual PM₂.₅ mass concentration. Although secondary sulfate contributed much more than secondary nitrate to PM₂.₅ on annual basis, the latter exceeded the former source factor when daily PM₂.₅ mass concentration was higher than 60 μg m⁻³, indicating the critical role nitrate played in PM₂.₅ episode events.]]></description>
      <pubDate>Fri, 16 Dec 2022 09:41:07 GMT</pubDate>
      <guid>https://trid.trb.org/View/2065230</guid>
    </item>
    <item>
      <title>Investigating detection probability of mobile survey solutions for natural gas pipeline leaks under different atmospheric conditions</title>
      <link>https://trid.trb.org/View/2031241</link>
      <description><![CDATA[The 2015 Paris agreement aims to cut greenhouse gas emissions and keep global temperature rise below 2 °C above pre-industrial levels. Reducing CH4 emissions from leaking pipelines presents a relatively achievable objective. While walking and driving surveys are commonly used to detect leaks, the detection probability (DP) is poorly characterized. This study aims to investigate how leak rates, survey distance and speed, and atmospheric conditions affect the DP in controlled below ground conditions with release rates of 0.5–8.5 g min−1. Results show that DP is highly influenced by survey speed, atmospheric stability, and wind speed. The average DP in Pasquill–Gifford stability (PG) class A is 85% at a low survey speed (2–11 mph) and decreases to 68%, 63%, 65%, and 60% in PGSC B/C, D, E/F, and G respectively. It is generally less than 25% at a high survey speed (22–34 mph), regardless of stability conditions and leak rates. Using the measurement data, a validated DP model was further constructed and showed good performance (R2: 0.76). The options of modeled favorable weather conditions (i.e., PG stability class and wind speed) to have a high DP (e.g., >50%) are rapidly decreased with the increase in survey speed. Walking survey is applicable over a wider range of weather conditions, including PG stability class A to E/F and calm to medium winds (0–5 m s−1). A driving survey at a low speed (11 mph) can only be conducted under calm to low wind speed conditions (0–3 m s−1) to have an equivalent DP to a walking survey. Only calm wind conditions in PG A (0–1 m s−1) are appropriate for a high driving speed (34 mph). These findings showed that driving survey providers need to optimize the survey schemes to achieve a DP equivalence to the traditional walking survey.]]></description>
      <pubDate>Mon, 31 Oct 2022 10:21:47 GMT</pubDate>
      <guid>https://trid.trb.org/View/2031241</guid>
    </item>
    <item>
      <title>A Trajectory Evaluation Platform for Urban Air Mobility (UAM)</title>
      <link>https://trid.trb.org/View/1994088</link>
      <description><![CDATA[Nowadays, there is an increase in the demand for optimized services in urban environments. However, ground transportation in big urban centers has been facing challenges for many years (e.g., resilience and congestion) and new paradigms have been proposed, such as the Urban Air Mobility (UAM) concept. UAM aims to enhance the urban transportation system using manned and unmanned aerial vehicles (i.e., Electric Vertical Takeoff and Landing - eVTOL - vehicles). Although UAM offers many benefits (e.g., cost reduction and increase in transportation capacity), many challenges need to be faced to enable safe and efficient operations. Furthermore, trajectory planning is challenging in the National Airspace System (NAS) and UAM operations due to several factors. Finally, new initiatives concerning UAM trajectory planning can be accelerated with the support of an automatic what-if platform capable of evaluating trajectories feasibility and efficiency. This research aims to propose a simulation platform for enabling trajectory evaluation in UAM operations. This platform, named Trajectory-Based Urban Air Mobility Simulator (TUS), focuses on simulating trajectories in the urban aerial environment. TUS enables users to test new UAM algorithms (e.g., flow management strategies, real-time evaluation of maneuvers effectiveness, airspace configurations) and simulate both manned and unmanned vehicles. Furthermore, TUS operation relies on a set of inputs and evaluates the trajectories generated from efficiency and safety perspectives. This process is performed using a Discrete Event Simulation (DES) approach. The experiments performed showed that TUS can perform a realistic evaluation of UAM trajectories and can be effortlessly used to simulate hundreds of scenarios.]]></description>
      <pubDate>Mon, 25 Jul 2022 11:50:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/1994088</guid>
    </item>
    <item>
      <title>A Safety-Aware Real-Time Air Traffic Flow Management Model Under Demand and Capacity Uncertainties</title>
      <link>https://trid.trb.org/View/1994045</link>
      <description><![CDATA[Inherent uncertainties of the air transportation system (ATS) can induce unexpected anomalies in its operations such as deviations in flight schedules, sudden imbalances of demands and capacities, etc.. Current air traffic flow management (ATFM) models rarely consider both demand and capacity uncertainties in their algorithms, and generally focus on minimizing the flight delays under deterministic constraints. Thus, to bridge this gap, the authors propose a framework for en-route ATFM while scrutinizing uncertainties in en-route capacity and demand and their imbalance, via a chance constraint based probabilistic approach. The proposed framework plays a key role in ensuring the safety of the overall ATS in terms of maintaining the safety separation between flights and constraining the capacity of the sectors as well. Moreover, flight level assignments scheme is proposed based on the Base of Aircraft Data (BADA) of the European Organization for the Safety of Air Navigation (EUROCONTROL) with the objective of minimizing the fuel consumption. The model further minimizes the overall expected delay of the system using the control actions of ground holding, speed control, rerouting, and flight cancellations. At the implementation stage, two phases of ATFM as pre-tactical and tactical are considered, in which the former focuses on generating optimal trajectories and the latter focuses on real-time updates of flight plans. The computational complexity is reduced by shrinking the feasibility region and decomposing the problem into maximum weighted independent sets. The experimental results of realistic large-scale problems demonstrate the effectiveness and computational feasibility of the authors' ATFM framework.]]></description>
      <pubDate>Mon, 25 Jul 2022 11:50:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/1994045</guid>
    </item>
    <item>
      <title>Capacitated Air/Rail Hub Location Problem With Uncertainty: A Model, Efficient Solution Algorithm, and Case Study</title>
      <link>https://trid.trb.org/View/1994032</link>
      <description><![CDATA[Well-designed multi-modal transportation networks are crucial for our connected world. For instance, the excessive construction of railway tracks in China, at speeds up to 350 km/h, makes it necessary to consider the interaction of rail with air transportation for network design. In this study, the authors propose a model for an air/rail multi-modal, multiple allocation hub location problem with uncertainty on travel demands. Their model is unique in that it integrates features from the existing literature on multi-modal hub location problem (including hub-level capacities, link capacities, direct links, travel cost and time, transit costs and uncertainty), which have not been considered simultaneously, given its high computational complexity. They formulate this model with <inline-formula> <tex-math notation="LaTeX">$O(n^{4})$ </tex-math></inline-formula> variables and show that the implementation of a Benders decomposition algorithm is inherently hard, because of the cubic number of variables in the master problem. Furthermore, they derive an iterative network design algorithm and additional improvement strategies: MMHUBBI which resolves a restricted problem by the solver CPLEX and MMHUBBI-DIRECT which re-designs the transportation network by a heuristic. Their evaluation on real-world dataset for Chinese domestic transportation shows that MMHUBBI provides a significant speed-up on all instances, compared to using CPLEX, while obtaining near-optimal solutions. MMHUBBI-DIRECT further reduces the runtime/memory usage but provides solutions with worse quality. The authors believe that their study contributes towards the design of more realistic multi-modal hub location problems.]]></description>
      <pubDate>Mon, 25 Jul 2022 11:50:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/1994032</guid>
    </item>
  </channel>
</rss>