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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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    <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>
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      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>Hybrid real-time bus bridging optimization tactic for a disrupted railway: fine-tuning routing and temporary-adding routing</title>
      <link>https://trid.trb.org/View/2643257</link>
      <description><![CDATA[The bus bridging method (BBM) is a promising approach to handle disrupted railway operations. Traditional BBMs usually lead to unfairness for passengers who use existing normal bus service. Different from previous studies, this study proposes a hybrid BBM that combines the fine-tuning bus bridging method (F-BBM) with the temporary-adding bus bridging method (T-BBM). This new BBM not only contributes to timely connecting the stranded passenger flow (efficiency), but also ensures the serviceability for original bus passengers (fairness). This paper develops a multinomial logit-based passenger travel choice model to capture heterogeneous impacts on stranded passengers. Additionally, a rolling-horizon approach is used to track the passenger flow dynamics. A case study of the Shanghai Jinshan commuter railway shows that the proposed new hybrid BBM can achieve a 26.33% and 40.57% reduction in total delays, in comparison with using a non-dynamic schedule and a scenario without using the BBM, respectively.]]></description>
      <pubDate>Wed, 22 Apr 2026 16:15:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/2643257</guid>
    </item>
    <item>
      <title>Feasibility of Engineered Cementitious Composites (ECC) as Joint Material for Accelerated Bridge Construction (ABC)</title>
      <link>https://trid.trb.org/View/2694442</link>
      <description><![CDATA[Advancements in manufacturing methods and the growing demand for high-strength materials in reinforced concrete have led to the development of steel reinforcing bars with strengths exceeding 100 ksi. These ultra-high-strength bars hold significant promise for bridge construction, as they could extend feasible span lengths beyond those achievable with conventional reinforcement while still meeting strength and serviceability requirements. Their use can also reduce girder depth, leading to material savings and lower overall construction costs. However, successful implementation requires addressing key concerns regarding serviceability and durability. Critical factors include corrosion resistance, structural behavior, and ductility of beams reinforced with these high-strength bars. 
The primary objective of the proposed work is to investigate the durability (corrosion resistance) and serviceability of concrete girders reinforced with very high-strength reinforcement, by testing bond-slip relationship between corroded and non-corroded steel rebars and concrete. 12 medium-span (8 in x 12 in x 10 ft) concrete beams will be cast and tested for strength and ductility. Six of the 12 beams will be subjected to accelerated corrosion. Under controlled conditions, the research team will test the strength and ductility characteristics of the beams reinforced with these bars. 
This study directly supports the mission of the Center for Healthy and Durable Transportation (CHDT), a University Transportation Center (UTC), whose primary research focus is enhancing the durability and service life of transportation infrastructure through innovative construction materials and techniques. By addressing the performance of very high-strength reinforcing bars in reinforced concrete girders and their behavior under corrosive conditions, this project advances the application of durable, next-generation materials for transportation infrastructure.

]]></description>
      <pubDate>Tue, 21 Apr 2026 13:16:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/2694442</guid>
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    <item>
      <title>Development of Adjustment Factors and Load Ratings via Statistical Analyses of the National Bridge Inventory Database</title>
      <link>https://trid.trb.org/View/2662988</link>
      <description><![CDATA[This study developed a new approach to establish baseline load ratings for bridges in Kansas without plans using data from the National Bridge Inventory (NBI). The approach is comprised of linear regression models to estimate load ratings for bridges with a condition rating of 8 or higher and adjustment factors to lower the estimated load rating to account for bridge condition ratings of 7 or lower. This approach beneficially establishes baseline load rating estimates for structures without prior ratings and secondary load ratings for bridges with prior load ratings to identify outliers and potential errors. The adjustment factors can be used to adjust load ratings obtained by any method to account for bridge condition if the condition was not specifically integrated into the analyses. Both the linear regression models and condition adjustment factors are designed to reflect trends among Kansas bridges within the NBI, not engineering judgment. This approach answers the following question for a given bridge: Knowing nothing more about the structure than what is available within the NBI, what is the expected rating based on similar bridges in similar condition within Kansas? The proposed linear regression models include bridge age, modeled design load, structure kind (construction material), structure type (truss, girder, etc.) and deck width because, among variables reported in the NBI, these were most closely correlated with load rating. The adjustment factors were developed based on the median reported load rating for bridges with various condition ratings, and uncertainty was estimated using a bootstrapping simulation. The proposed models demonstrated satisfactory performance, capturing approximately half the variance observed in the data for the Inventory (R2 = 0.50) and Operating (R² = 0.49) Ratings. Further validation and refinement, inclusion of additional predictors, and exploration of alternative methods are suggested to improve accuracy and applicability.]]></description>
      <pubDate>Thu, 05 Feb 2026 11:56:06 GMT</pubDate>
      <guid>https://trid.trb.org/View/2662988</guid>
    </item>
    <item>
      <title>Towards an integrated, explainable, and computationally efficient metamodel-based optimization framework for seismic rehabilitation planning of gas pipeline networks</title>
      <link>https://trid.trb.org/View/2618387</link>
      <description><![CDATA[Gas pipeline networks (GPNs) are essential infrastructure systems that face significant risks during seismic events, leading to disruptions in energy supply and cascading societal impacts. Optimizing seismic rehabilitation plans for GPNs under resource constraints is challenging due to the high computational costs and black-box nature of conventional simulation-based optimization techniques. This study addresses these challenges by introducing an integrated, explainable, and computationally efficient framework for optimizing seismic rehabilitation plans of GPNs. This framework creates physics-based metamodels to approximate complex simulation models, ensuring computational cost reduction, and then integrates those metamodels with exact mathematical optimization, ensuring solution optimality and transparency. This study developed two metamodels for maximizing the expected post-earthquake serviceability index (EPSI), a flow-based metric that evaluates a network's ability to meet gas demand after an earthquake. EPSI is evaluated as the ratio of post to the pre-earthquake demand across the network. Metamodel 1 approximates EPSI based solely on individual pipe rehabilitation status, while Metamodel 2 enhances accuracy by incorporating interactions between spatially connected pipes. Results indicate that Metamodel 2 outperforms Metamodel 1 in predictive accuracy, achieving higher R² and lower RMSE and MAE values, making it a more robust model for estimating EPSI. Because of its complex nature, Metamodel 2 requires slightly more computational time for optimization. However, both metamodels significantly reduce computational effort compared to using simulated annealing (SA), achieving a computational time reduction of up to 70.81 %. This research offers a robust and explainable framework that supports effective seismic rehabilitation planning, enhancing GPN reliability under resource constraints.]]></description>
      <pubDate>Mon, 26 Jan 2026 14:44:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/2618387</guid>
    </item>
    <item>
      <title>Quantifying the counteracting impacts of climate change on large-scale pavement infrastructure serviceability</title>
      <link>https://trid.trb.org/View/2652512</link>
      <description><![CDATA[This study quantifies competing climate-change effects, temperature rise versus reduced freezing, on pavement networks using over 35 years of records from more than 1,100 sections. We combine explainable machine learning (ML) with Monte Carlo simulation to propagate global climate model (GCM) projections to future infrastructure impacts, considering the two-layer uncertainty from climate ensemble and ML residuals. Results reveal substantial inter-GCM model differences and occasional opposing trends, underscoring climate projection uncertainty. Trained ML models accurately predict long-term pavement performance; the freezing index and air temperature are the two dominant drivers. Reduced future freezing tends to extend service life, partially offsetting warming’s negative effects. Thus, climate change does not always accelerate pavement deterioration: in some regions (notably wet, freeze-prone zones) and for some time horizons or scenarios, net effects can be neutral or beneficial. In wet, freeze zones, pavement service life is being extended in nearly 65 % simulations under SSP585 by 2050–2060, whereas dry, freeze counterparts only show a figure of around 35 %. These findings indicate that pavement resilience assessments should consider both warming and changing freeze–thaw regimes rather than temperature alone under climate uncertainty and inform local adaptation decisions practically.]]></description>
      <pubDate>Mon, 26 Jan 2026 08:41:41 GMT</pubDate>
      <guid>https://trid.trb.org/View/2652512</guid>
    </item>
    <item>
      <title>Optimization of reinforced concrete bridge girders using reliability-based design and active learning to ensure long-term serviceability</title>
      <link>https://trid.trb.org/View/2625252</link>
      <description><![CDATA[Bridges play a critical role in ensuring the safe and continuous movement of people and goods, making their structural integrity over time a key concern in civil engineering. This study introduces a novel two-stage Reliability-Based Design Optimization (RBDO) approach for optimizing the cross-sectional dimensions of reinforced concrete bridge girders at the end of their service life. The method explicitly accounts for key time-dependent degradation mechanisms-creep, shrinkage, corrosion, and traffic growth-often neglected or treated in isolation in prior research. The first stage involves a deterministic optimization to provide a cost-effective initial design. The second stage applies an active learning-based RBDO using a hybrid surrogate model that combines artificial neural networks (ANN), radial basis functions (RBF), and support vector regression (SVR). This adaptive strategy significantly reduces the number of full-model evaluations required to estimate failure probabilities, ensuring both computational efficiency and accuracy. Validation against benchmark problems confirms the robustness of the proposed framework in terms of both reliability estimation and optimization. When applied to a real bridge case, the method achieved convergence in only 11 deterministic and 15 RBDO iterations, resulting in a 47% reduction in computational cost compared to a standard Adaptive Kriging Monte Carlo Simulation (AK-MCS)-based approach. Overall, the proposed methodology enables a more realistic, economical, and computationally efficient design of bridge structures over their entire lifespan.]]></description>
      <pubDate>Mon, 29 Dec 2025 09:35:56 GMT</pubDate>
      <guid>https://trid.trb.org/View/2625252</guid>
    </item>
    <item>
      <title>WinPRES User Manual Version 1.0</title>
      <link>https://trid.trb.org/View/2582730</link>
      <description><![CDATA[This manual is a guide to using WinPRES, which is the developed Windows® version of the program PRES. The Appendix of this manual includes some examples to show the user how to input data and how to get output answers. A simple model was developed to estimate the vertical movement at any point in a pavement in order to correlate the vertical movement to the roughness measurements made in different wheel paths of the pavement sections. Another model was developed to predict the pavement roughness in terms of serviceability index (SI) and international roughness index (IRI) by correlating regression constants obtained from the roughness analysis to the vertical movement estimated from the vertical movement model. The vertical movement model and the roughness model developed were then assembled in the program PRES written in the Fortran language. The input data are entered to the program through a Windows® graphical user interface developed using a Visual Basic tool. PRES is a model to estimate the development of pavement roughness on expansive soil subgrades, including the effects of the depth of a vertical moisture barrier and the thickness of inert and stabilized soil, if desired.]]></description>
      <pubDate>Sun, 30 Nov 2025 16:39:38 GMT</pubDate>
      <guid>https://trid.trb.org/View/2582730</guid>
    </item>
    <item>
      <title>Development of Statistical Deterioration Model for Low Volume Roads in Indian Scenario</title>
      <link>https://trid.trb.org/View/2407382</link>
      <description><![CDATA[Pavement serviceability is the concept representing the level of service that pavement structure offers to the road users. International Roughness Index (IRI) and Present Serviceability index (PSI) are the parameters which are used to represent the performance of pavement. Road roughness is considered to be the most important parameter affecting vehicle operating costs which account for a large proportion of total transport costs. Roughness is concerned with vehicle vibration, operating speed and wear & tear of the wheels. It affects the road user cost to a significant extent. Therefore, roughness of the pavement plays the decisive role in exercising the option of implementing the optimum maintenance and rehabilitation strategies of the road network at appropriate time. Four study stretches, which include conventional and treated, each of 400 m long were selected. The pavement distresses are collected, processed and analysed for developing a deterioration model. Pavement distress viz cracking, rutting, ravelling, potholes, patching were measured. Rating (both visual and ride rating) studies were also carried. An attempt is made to develop International Roughness Index equation for the selected study stretches. A model is developed to correlate International Roughness Index (IRI) with different types of pavement distresses.]]></description>
      <pubDate>Mon, 22 Sep 2025 08:49:32 GMT</pubDate>
      <guid>https://trid.trb.org/View/2407382</guid>
    </item>
    <item>
      <title>Highway Signing Research Phase II. Characterization of Sign-Facing Materials</title>
      <link>https://trid.trb.org/View/2560872</link>
      <description><![CDATA[A program was conducted to develop, through laboratory and related field studies, sufficient information on which to judge the adequacy of current performance specifications for sign-facing materials. Employing materials in common use in highway signing, studies were carried out to characterize them with respect to qualities identifiable with optimum sign performance and serviceability. Portions of the work were concerned with defining objective criteria for specifying those qualities and examining test procedures and requirements to evaluate the materials with respect to the criteria. The general technical areas of work were: 1) durability, including mechanisms of deterioration; 2) photometric properties; 3) cleanability; 4) methods and ease of fabrication; 5) physical and mechanical properties; 6) selection and development of photometric instruments; and 7) others -- including sign monitoring, review of Texas Highway Department data on signing materials, and accelerated tests.]]></description>
      <pubDate>Sat, 02 Aug 2025 15:40:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/2560872</guid>
    </item>
    <item>
      <title>Mathematical Model for Assessing the Reliability of Water Supply Networks</title>
      <link>https://trid.trb.org/View/2407893</link>
      <description><![CDATA[A mathematical model for assessing the reliability of water supply networks, based on Markov random processes with a discrete set of states and continuous time (continuous Markov chains), is proposed in this paper. A marked-up graph of the states of the water supply network is constructed to analyze the model. Cauchy problem solution for a system of Kolmogorov differential equations with initial conditions is given. The application of this model to a real water supply network is demonstrated in this paper. The proposed modeling algorithm makes it possible to objectively assess the reliability of any water supply networks for the purpose of long-term prediction of their reliable condition and ensuring their serviceability for the entire period of their operation.]]></description>
      <pubDate>Mon, 28 Jul 2025 13:51:29 GMT</pubDate>
      <guid>https://trid.trb.org/View/2407893</guid>
    </item>
    <item>
      <title>Spectral Analysis of Vertical Vibration Response of Footbridges under Crowd Loads Using Lyapunov Equations</title>
      <link>https://trid.trb.org/View/2563684</link>
      <description><![CDATA[Over the years, various methodologies have emerged for assessing the effect of crowds on footbridges. Given the stochastic nature of such excitations and the desired linear behavior of the structure, employing tools rooted in random-vibration theory is encouraged. This paper presents an analytical approach for evaluating the root-mean-square of vertical vibrations. The approach involves solving the Lyapunov equations for a structural system in the state-space, subjected to a filtered white-noise input. A serviceability evaluation procedure based on the presented analysis approach is presented as well. For the proposed procedure, commodifiable filters which articulate the excitation in the state-space, are developed. These filters express the mean spectral densities of crowd excitations, and account for various distributions of a crowd along a footbridge. A single analysis of a footbridge, subjected to such loads, results with the mean of the root-mean-square response of interest. Hence, the approach may appeal to engineers for implementation in design practice. Furthermore, by using the Lyapunov equations, the suggested procedure significantly surpasses the traditional spectral density analysis in terms of computational efficiency. Therefore, this approach may be preferred in cases when many analyses are required.]]></description>
      <pubDate>Fri, 25 Jul 2025 17:16:59 GMT</pubDate>
      <guid>https://trid.trb.org/View/2563684</guid>
    </item>
    <item>
      <title>Raft Foundations Under Combined Vertical-Moment-Horizontal Loading: A Numerical Study on Design-Adaptive Serviceability</title>
      <link>https://trid.trb.org/View/2488247</link>
      <description><![CDATA[The effect of combined vertical (V), moment (M), and horizontal (H) loading generated by wind, earth pressure, earthquake, and gravity loading is not realized in conventional foundation design. Despite the advantages of VMH failure envelopes, there is a lack of consideration of the serviceability, resulting in a new prospect recognized as design envelopes. It involves triple displacement metrics of vertical displacement, rotation angle, and horizontal displacement. The present research delves into the effect of combined load interaction on the behavior of rafts in loose and medium mixed deposits. The performance of the raft foundation under combined loading is evaluated using a 3D finite element analysis. Failure and design envelopes for the validated raft system are developed considering combined loading associated with dominant system parameters comprising the raft breadth, embedment depth, and subsoil strength. Eventually, a dataset of ten case studies comprising various geomaterials and foundation types and documented settlement and tilt values is applied to conform to the proposed prospect. Three efficacy scenarios are defined based on minor, major, and severe damage levels. Design and failure surface boundaries distinguish the efficacies. Realizing serviceability and failure aspects in a coupled form leads to a more reliable foundation design.]]></description>
      <pubDate>Fri, 18 Jul 2025 09:05:44 GMT</pubDate>
      <guid>https://trid.trb.org/View/2488247</guid>
    </item>
    <item>
      <title>Project 187-1 Texas Transportation Institute Serviceability Index Values, Moisture Barrier Sites</title>
      <link>https://trid.trb.org/View/2560888</link>
      <description><![CDATA[This is Appendix 1-4 to a report for Project 187-1 conducted by the Texas Transportation Institute. It shows Serviceability Index Values at moisture barrier sites of flexible pavements in San Antonio, Texas.]]></description>
      <pubDate>Mon, 14 Jul 2025 14:20:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/2560888</guid>
    </item>
    <item>
      <title>Probabilistic corrosion initiation assessment of marine concrete bridge components via exposure tests and numerical simulations</title>
      <link>https://trid.trb.org/View/2568576</link>
      <description><![CDATA[Durability performance is crucial for the premaintenance of marine concrete bridges. To assess the probability of corrosion initiation, long-term exposure tests are conducted first to obtain the chloride diffusion properties. The chloride binding coefficients, surface chloride concentrations and age reduction factors are analyzed on the basis of the test results. A stochastic chloride diffusion model and a numerical simulation method for chloride diffusion are established. The influences of the actual aggregate morphology on chloride diffusion are investigated via numerical simulations. Finally, a method for assessing the probability of corrosion initiation is developed, and a case study is completed. The results show that in the atmosphere zone, the chloride binding coefficient increases with depth, whereas the growth rate decreases. In the splash zone, the binding coefficient first decreases but then increases when the depth is less than 10 mm. After that, the binding coefficient increases rapidly to approximately 0.90 and remains stable. With increasing exposure period, the surface chloride concentration increases logarithmically. The age reduction factor is 0.6129 for the reported exposure tests. The incorporation of actual aggregate leads to randomness in the chloride concentration at the same depth. There is a critical depth in concrete component, before which the blocking effect of aggregate increases the chloride concentration and after which the blocking effect decreases the chloride concentration. The critical depth increases with increasing exposure period. Through the proposed method for assessing the probability of corrosion initiation, the residual durability life, which incorporates the randomness of chloride diffusion behavior and the critical chloride concentration, can be obtained, which is crucial for maintenance decision-making. According to the case study, the tensile stress level of the concrete has a significant influence on the residual durability life, and the residual durability life of the corner rebar is obviously lower than that of the noncorner rebar.]]></description>
      <pubDate>Thu, 26 Jun 2025 16:12:28 GMT</pubDate>
      <guid>https://trid.trb.org/View/2568576</guid>
    </item>
    <item>
      <title>Determinants of school bus service satisfaction in private schools in Ghana: Managerial implications</title>
      <link>https://trid.trb.org/View/2548230</link>
      <description><![CDATA[Although School Bus Transportation Services (SBTS) enhance safe and supervised travel that impacts educational outcomes, there is a growing service decline in some private schools in Ghana. Given the dearth of research on SBTS satisfaction in Africa's private schools, policymakers and education administrators are unable to find managerial solutions. This study investigates the determinants of school bus service satisfaction in the Sunyani Municipality, Ghana, using a survey of 403 schoolchildren and 40 staff members from twenty private schools. Multivariate analyses showed that the frequency of bus breakdowns is a critical determinant of ridership, whereas cost is insignificant. Satisfaction depends on bus service information, serviceability, drivers' empathy towards riders, safety/security, the physical appearance of crew and buses, and responsiveness/reliability of services. Notably, there is no transport policy or department regulating SBTS management in Ghana's private schools. Stakeholders can use the findings of this study to create a policy framework to improve the management of SBTS.]]></description>
      <pubDate>Thu, 26 Jun 2025 11:42:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/2548230</guid>
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