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    <title>Transport Research International Documentation (TRID)</title>
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    <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>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>A systematic numerical framework to predict welding residual stress distributions in curved steel plates for shipbuilding and offshore applications</title>
      <link>https://trid.trb.org/View/2704250</link>
      <description><![CDATA[This study develops an empirical formula to predict the residual stress distribution (RSD) in curved welded plates, a common structural component in ships and offshore structures. Most existing empirical models rely on limited point-based data for calculating RSD. However, the RSDs vary with geometrical location and thickness layer, reflecting geometric non-uniformity caused by different thermal effects. To address this limitation, 120 three-dimensional thermo-elasto-plastic finite element (FE) analyses were conducted, covering a wide range of thicknesses (t = 8–40 mm) and flank angles (θ = 5°– 45°). Through the proposed method by the full-field averaged model, the effects of the geometrical characteristics (i.e., flank angle and thickness) on the width and stress of the RSD were analysed. Based on the flank angle analysis results, idealised stress profiles (such as rectangles and triangles) were adopted to develop an empirical formula for predicting RSD. The accuracy was verified against FEA results with low dispersion as indicated by a mean close to 1.0 and a coefficient of variation (COV) approaching 0.0. The proposed formula can be considered a curvature-related geometric effect, based on a full-field averaged model of RSD in curved plates under reliable scenarios. Moreover, the variation trends of tensile and compressive stress regions (i.e., width and stress) were quantitatively analysed with respect to thickness and flank angle. Therefore, it provides a distinct advancement over existing methods by enabling a physically consistent and geometry-sensitive evaluation of welding-induced residual stresses. This framework provides a practical, efficient tool for the preliminary structural assessment of marine and offshore curved plates.]]></description>
      <pubDate>Thu, 13 Aug 2026 17:07:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/2704250</guid>
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    <item>
      <title>Establishment of Break Point Model for Railway Wireless Communication System in Curved Tunnels</title>
      <link>https://trid.trb.org/View/2731661</link>
      <description><![CDATA[Accurate prediction of radio wave propagation in tunnels is fundamental to designing reliable high-speed railway (HSR) wireless communication systems, especially under complex propagation conditions like curved tunnels. The propagation characteristics of radio waves in curved tunnels are very complex, and explaining radio wave propagation with only one mechanism and the corresponding model limits the accuracy of path loss prediction. Therefore, delineating propagation mechanisms and establishing break point (BP) prediction models in curved tunnels are crucial for designing reliable railway wireless communication systems. In this study, a BP prediction model is developed between different propagation mechanisms in a curved tunnel based on Fresnel theory for the first time. The method delineates the different propagation mechanisms in line-of-sight (LOS) and non-line-of-sight (NLOS) transmissions in curved tunnels. The model provides a fast prediction expression for the BP of curved tunnels, while integrating the effects of the radius of curvature (ROC), operating frequency, tunnel parameters, and antenna location. We found the optimal location for placing antennas along the curved tunnel cross-section, which maximizes the Fresnel zone clearance and ensures good radio wave coverage. Finally, the electromagnetic distribution of the curved tunnel was simulated by a simulation platform based on the finite element method (FEM) and the simulation results verify the accuracy of the BP prediction model. Compared with the baseline path loss model, the predicted BP in this paper significantly improves the accuracy of the two-slope path loss model. The results help guide the layout of transmitting antennas in curved tunnels and reliable parameters for HSR wireless communication systems.]]></description>
      <pubDate>Wed, 12 Aug 2026 15:14:55 GMT</pubDate>
      <guid>https://trid.trb.org/View/2731661</guid>
    </item>
    <item>
      <title>Influence of Urban Underground Spiral Ramp Curve Design on Vehicle Running Performance</title>
      <link>https://trid.trb.org/View/2691510</link>
      <description><![CDATA[Urban underground spiral ramps’ continuous curves and the monotonous tunnel environment increase driving safety risks and reduce vehicle stability. To clarify the influence of road geometric alignment parameters on vehicle acceleration in urban underground spiral ramp curves, a real vehicle test was conducted on the Jiefangbei Underground Ring Road - Hongyamen Underground Road in Yuzhong District, Chongqing, China. On-board instruments collected acceleration data from 20 drivers to analyse how curve radius and angle affect the vehicle’s three-axis acceleration. The results show that: (1) The exit acceleration of the spiral ramp curve is positively correlated with the curve radius and negatively correlated with the turning angle, while entrance deceleration exhibits the opposite trend. (2) Lateral acceleration is negatively correlated with curve radius but positively correlated with turning angle. (3) Vertical acceleration increases with curve radius on upward curves and decreases on downward ones; the opposite occurs with turning angle. (4) Vehicle acceleration differs significantly under varying radii and turning angles. The average exit acceleration is higher for ordinary-radius (or small turning angle) curves than for small-radius (or large turning angle) curves, while the average lateral acceleration exhibits the opposite trend. These findings reveal passenger car driving behaviour characteristics on urban underground spiral ramps, supporting future curve geometric design and safety studies.]]></description>
      <pubDate>Mon, 13 Jul 2026 10:45:19 GMT</pubDate>
      <guid>https://trid.trb.org/View/2691510</guid>
    </item>
    <item>
      <title>Parametric comparative analysis of curved and straight submerged floating tunnels under wave loading</title>
      <link>https://trid.trb.org/View/2653033</link>
      <description><![CDATA[To date, most research on submerged floating tunnels (SFTs) has been limited to straight geometries, whereas horizontally curved geometries remain insufficiently investigated in terms of both theoretical aspects and structural behavior, despite their potential benefits in improving stiffness through arch action. To address this research gap, this study derives the equations of motion and natural boundary conditions accounting for mooring lines. Subsequently, a comparative investigation of the structural behavior of curved and straight tunnels is carried out through finite element simulations. The structural responses of a 1 km-span tunnel were evaluated under two mooring configurations—vertical (Type 1) and inclined (Type 2)—with particular focus on maximum responses and arching effects, in order to identify the most rational mooring configuration. Additional analyses under Type 2 were performed to evaluate the effects of span length (1000 m, 2000 m, and 4000 m) and rise-to-span ratio on natural frequencies, bending moments, axial forces, and von Mises stresses. The results revealed that curvature induced an arching effect, redistributing internal forces induced by waves into axial forces and thereby significantly reducing structural responses. For the 4000 m span case, the maximum von Mises stress was reduced by as much as 87 %, remaining only 13 % of that observed in the straight tunnel. These findings demonstrate the structural efficiency of curved SFTs, particularly in long-span applications.]]></description>
      <pubDate>Mon, 06 Apr 2026 08:50:03 GMT</pubDate>
      <guid>https://trid.trb.org/View/2653033</guid>
    </item>
    <item>
      <title>Continuous path smoothing for deep-sea mining vehicles using B-spline curves</title>
      <link>https://trid.trb.org/View/2625500</link>
      <description><![CDATA[The original path produced by the path planning algorithm has many sharp points, and the deep-sea mining vehicles (DSMV) need to accelerate and decelerate frequently or even turn in place, which is not conducive to saving energy. The smoothness and continuity of paths are more suitable for DSMV traveling on the seabed, and this paper proposes a path smoothing algorithm based on cubic B-spline curves. According to the motion characteristics of the DSMV, the force analysis of its steering process is conducted to derive the constraint of the minimum turning radius under the skidding condition. It is applied as a curvature constraint in the proposed smoothing algorithm, and simulation experiments are carried out in 2D terrain and 3D terrain, respectively. The results show that the smoothed path satisfies the maximum curvature constraint and guarantees C² continuity, which better matches the requirements for mining vehicles on the seabed.]]></description>
      <pubDate>Tue, 02 Dec 2025 09:58:27 GMT</pubDate>
      <guid>https://trid.trb.org/View/2625500</guid>
    </item>
    <item>
      <title>Modified circular curve-based impact angle control guidance</title>
      <link>https://trid.trb.org/View/2593790</link>
      <description><![CDATA[To plan the path for unmanned aerial vehicles (UAVs) considering the impact angle and acceleration constraints, a novel geometric rule is proposed in this paper. Firstly, under the nonlinear engagement kinematics, the geometric rule is derived from the modified circular curve including two parameters, one for the convergence of the acceleration, the other for extending the flight envelope. Furthermore, the convergence of the nominal guidance law developed from the geometric rule is rigorously proved. Secondly, to eliminate the angle tracking error regardless of the initial error size, a fixed-time convergent controller is adopted to formulate the impact angle control guidance law. Moreover, the implementation of the proposed guidance law only requires angle information, which can be readily obtained by the on-board device. The proposed guidance law is also applicable for varying-speed UAVs and moving targets. The simulation results and the comparative studies demonstrate the validity and superiority of the proposed guidance law.]]></description>
      <pubDate>Wed, 29 Oct 2025 09:13:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/2593790</guid>
    </item>
    <item>
      <title>Typology of Bike Lane Users Motion on Horizontal Curves: A Surrogate Safety Approach</title>
      <link>https://trid.trb.org/View/2604620</link>
      <description><![CDATA[This study examines the safety implications of horizontal curves in bike lanes, focusing on cyclists’ and e-scooter riders’ behavior. As cities transition from autocentric to sustainable transportation systems, bike lanes are increasingly integrated into urban infrastructure, particularly in Europe. Despite the benefits of active transportation, safety concerns for bike lane users persist. Horizontal curves can pose significant safety risks as a rest of lower radii, higher curvature degrees, and reduced surface friction. This study has shown that cyclists and e-scooter riders are significantly affected by sudden changes in geometry, reacting by aggressive maneuvers and increased risks of conflict and fall. To address this, a motion analysis methodology is proposed to identify risky maneuvers in bike lanes, using microscopic analysis of trajectory and speed, revealing naturalistic reactions of bike lane users to various curve geometries. The study employs previous track typology and density-based spatial clustering algorithms to cluster distinct trajectory patterns. Additionally, a decision tree regression model finds the degree of curvature as the most effective variable in user motion behavior. Findings indicate that horizontal curve geometry significantly influencing user behavior. Generally, left-turn maneuvers on curves show greater diversity and higher risks, especially in sharp curves on a bidirectional bike lane. Speed analysis reveals that reducing curve radii increases speeding behaviors and variance. The proposed method is scalable and can help in the development of mitigation strategies such as geometric treatments, surface skid resistance improvements, enhanced signage, and enforcement in high-risk curves identified after using this approach.]]></description>
      <pubDate>Fri, 03 Oct 2025 10:20:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/2604620</guid>
    </item>
    <item>
      <title>SAR Research: How lateral range curves improve rescues</title>
      <link>https://trid.trb.org/View/2595476</link>
      <description><![CDATA[The United States Coast Guard conducts search and rescue (SAR) operations over 3.4 million nautical square miles, responding to an average of 45 cases per day. For some cases, there is uncertainty about the exact location or condition of the people in distress, which could require a search across an expansive area. To aid in successful searches, the Coast Guard uses the Search and Rescue Optimal Planning System (SAROPS). SAROPS utilizes the lateral range curve (LRC) to quantify the probability of detecting a search object as a function of the range between the search asset and the object. The Coast Guard Research and Development Center (RDC) has developed LRCs and associated sweep widths that have been used by the service and international maritime SAR community since the late 1970s. In recent years, the RDC has examined means of reducing the demand for empirical data when computing LRCs. It has defined a new process that uses physics-based models to predict the LRCs of human-in-the-loop sensors, and leverages small, targeted field experiments to validate the predictions. The RDC’s Data, Modeling, & Decision Support Research Program is continuing to evaluate this new approach to calculating LRCs, with plans to validate the physics-based models against empirical data collected in accordance with the historical approach.]]></description>
      <pubDate>Fri, 26 Sep 2025 13:39:59 GMT</pubDate>
      <guid>https://trid.trb.org/View/2595476</guid>
    </item>
    <item>
      <title>Nonlinear Thermomechanical Transient Response of Initially Stressed FGM Shallow Shell Panels Including Porosity and Geometric Imperfection</title>
      <link>https://trid.trb.org/View/2560838</link>
      <description><![CDATA[This paper aims to investigate the simultaneous effects of initial stresses, porosities, geometrical imperfections, elastic foundations, and high temperatures on the nonlinear transient response of spherical and cylindrical shell panels made up of functionally graded material (FGM) and that have undergone suddenly applied uniform transverse loads. Initial thermomechanical stresses are caused by reactive forces produced at tangentially restrained edges or active axial compressive loads applied at movable curved edges of cylindrical panels. The pores are distributed in FGM via even and uneven distribution patterns. Due to the presence of pores, the effective properties of porous FGM are evaluated by employing a modified mixture rule. Mathematical derivations governing the dynamic behavior of shallow shell panels are performed on the basis of first-order shear deformation theory incorporating von Kármán–Donnell nonlinearity, initial geometric imperfection, and interactive pressure from two-parameter foundations. Analytical solutions are adopted to satisfy simply supported boundary conditions and the Galerkin method is utilized to obtain a time-variable ordinary differential equation of quadratic and cubic nonlinearities. This differential equation is solved using the fourth-order Runge–Kutta integration method to trace temporal response paths. Through parametric studies, numerous effects on the nonlinear temporal response and findings are analyzed and discussed.]]></description>
      <pubDate>Fri, 18 Jul 2025 09:06:52 GMT</pubDate>
      <guid>https://trid.trb.org/View/2560838</guid>
    </item>
    <item>
      <title>Automated extraction of geometric information from LiDAR point clouds on curved ramps</title>
      <link>https://trid.trb.org/View/2570512</link>
      <description><![CDATA[Several approaches have been implemented to extract road geometric information from point clouds originating from different LiDAR systems. However, they are unsuitable for scenarios lacking trajectory data and involving road widening and complex alignment combinations, particularly in the case of curved ramps. This article proposes an automated framework to process discrete LiDAR point clouds and extract geometric information for these ramps. The framework primarily contributes in three key areas: 1) A node identification method is proposed to accurately segment the horizontal and vertical alignments, especially for fluctuating curvature and varying longitudinal grade; 2) By determining road axis points using road markings and boundaries, the framework supports road widening and all types of ramp cross sections; 3) Cross sections are extracted without slicing and rotating, allowing width calculation within each section. Test results show that the framework achieves geometric extraction accuracies between 90.79 % and 100 %, demonstrating its effectiveness for curved ramps.]]></description>
      <pubDate>Fri, 18 Jul 2025 09:05:42 GMT</pubDate>
      <guid>https://trid.trb.org/View/2570512</guid>
    </item>
    <item>
      <title>Mechanical properties of irregularly curved offshore pipelines in sinking process</title>
      <link>https://trid.trb.org/View/2564527</link>
      <description><![CDATA[An analytical method for effectively evaluating the mechanical properties of the offshore pipelines with irregularly curved shapes during sinking process is presented. Based on the tubular spatial Euler-Bernoulli beam model, the static equilibrium equations of the irregularly curved offshore pipelines are established by the finite element method (FEM), and the stresses and strains of the pipelines and the tensions of the slings are obtained. By comparing with the strains obtained from the OrcaFlex software and experiment, the validity and correctness of the analytical calculation model are verified. The mechanical performances of the irregularly curved offshore pipelines in the air stage and passing the splash zone stage are calculated by the present method, and the stress conditions of the pipe for sinking schemes with 3 and 4 ropes are compared. The influences of pipeline diameter, wall thickness, thickness of concrete coating, and strut on the mechanical characteristics of the irregularly curved offshore pipelines are explored. The analytical model can provide theoretical guidance for offshore pipeline installation operations.]]></description>
      <pubDate>Tue, 24 Jun 2025 15:24:48 GMT</pubDate>
      <guid>https://trid.trb.org/View/2564527</guid>
    </item>
    <item>
      <title>Design Curves for Time-Dependent Preloading Consolidation with PVDs Considering the Effects of Parabolic Permeability in the Smear Zone and Overlapping Smear Zones</title>
      <link>https://trid.trb.org/View/2516445</link>
      <description><![CDATA[The present research provides the design curves for preloading consolidation with prefabricated vertical drains that account for the effects of parabolic horizontal permeability distribution in the smear zone and the overlapping smear zones created by closely spaced drain systems. Additionally, the time-dependent application of surcharge preloading is also taken into consideration. When examining the overlapping of smear zones that result from the small spacing between drains, the results showed that in a triangular pattern, the ratios of the minimum center-to-center spacing between drains to the drain diameter are 1.52 and 10.85 for the smear zone size ratios of 2 and 20, respectively. The same ratios are 1.42 and 10.09 for a square pattern. The paper also outlines the design steps with an example. Ultimately, the implemented design curves are applied to the test embankments of the reclaimed Port of Brisbane to determine the design spacing. The results demonstrate that the predicted drain spacing, derived from the proposed design curves, closely aligns with the drain spacing used in the existing test embankments.]]></description>
      <pubDate>Tue, 27 May 2025 09:33:56 GMT</pubDate>
      <guid>https://trid.trb.org/View/2516445</guid>
    </item>
    <item>
      <title>Study of Asymmetric Failure Patterns for Curved Tunnels Using Visualized Transparent Soil Tests</title>
      <link>https://trid.trb.org/View/2534147</link>
      <description><![CDATA[With increasing urbanization, many of the current structures in the underground severely limited the space below ground. Shield tunnels need to be built in curved lines to bypass already established tunnels, pilings, and other buildings. Considering that a curve tunnel is overexcavated on the inner side (overexcavated side) during the excavation process and the difference in the jacking forces on the inside and outside of the tunnel, the study of the curved tunnel working face stability is more complicated. In this paper, a curved tunnel excavation model is designed independently, and the visualized transparent soil model test of the curved tunnel is carried out by combining with particle image velocimetry software to investigate the soil progressive damage process during curved tunnel excavation. On basis of designed modeling tests, a three-dimensional asymmetric spatial pattern of the soil arch was further given by using the numerical simulation method, and a detailed analysis of the internal friction angle and the curvature radius on the arch effect of sandy soil was performed. It is indicated that the soil ahead of the curved tunnel shows the shape of a crescent in the cross section, which is offset toward the inner side, and a bubble shape in the longitudinal section. In addition, the maximum value of the settlement tank during tunneling is located on the inner side of the curved tunnel, and there is an asymmetric distribution of the settlement curve along the central axis. The soil ahead of the curved tunnel’s working face will have an increased offset to the inside.]]></description>
      <pubDate>Wed, 23 Apr 2025 11:54:10 GMT</pubDate>
      <guid>https://trid.trb.org/View/2534147</guid>
    </item>
    <item>
      <title>Driving safety evaluation of longitudinal slope and curve combination of extra-long underwater tunnels</title>
      <link>https://trid.trb.org/View/2449007</link>
      <description><![CDATA[Extra-long underwater tunnels are important channels for realising cross-water traffic and play a crucial role in urban traffic. To study the influence of longitudinal slope, curve and combination of both on the driving safety of extra-long underwater tunnels, the physiological changes of drivers under the effect of different combinations of longitudinal slope and curve are analyzed. A driving risk evaluation model is established by introducing the coupling coordination degree, quantifying the relationship between the longitudinal slope, curve radius, and driving risk, and a reasonable combination of the longitudinal slope and curve is selected. The results indicate that there are significant differences in the physiological load of drivers between each longitudinal slope and curve. More specifically, the smaller the longitudinal slope and the larger the curve radius, the smaller the coupling coordination degree and better the driving safety. For a small longitudinal slope area (− 1.5% < longitudinal slope < 1.5%), the minimum curve radius is 400 m, and the ideal curve radius is ≥ 1700 m. For a small radius curve area (curve radius < 1000 m), the maximum longitudinal slope is − 1.5% (downhill area) and 2% (uphill area), respectively.]]></description>
      <pubDate>Mon, 13 Jan 2025 10:24:41 GMT</pubDate>
      <guid>https://trid.trb.org/View/2449007</guid>
    </item>
    <item>
      <title>Rollover Stability Analysis of Trucks-Effect of Curve Geometry and Operating Speed</title>
      <link>https://trid.trb.org/View/2407371</link>
      <description><![CDATA[Road crashes have become a major concern worldwide. Rural highways account for more than 66% of total road fatalities as the speed of vehicles on these highways are very high. Rollover crashes at curved roads in these areas are mostly serious and cause severe damage and injury than other kinds of vehicle crashes. The relatively low rollover stability of heavy commercial vehicles promotes rollover and contributes to the number of heavy vehicle crashes. Inconsistency in geometric design of rural curves can present an unpredictable road profile before the driver resulting in erroneous and dangerous maneuvers. A way to improve safety on curves is improving its geometric design. Research has been conducted to evaluate the dynamic behavior of vehicles on curves and their relation with highway geometry. But uniformity was not observed in the geometric parameters identified to affect rollover stability. So, this research evaluated the influence of geometry of horizontal curves on rollover stability of vehicles with focus on two-axle trucks loaded up to its Gross Vehicle Weight (GVW). The lateral behavior of a cornering truck under varying curve geometry was examined using vehicle dynamics simulation software IPG TruckMaker and lateral acceleration experienced by the truck while cornering was used as a measure of its stability against rollover. It was observed that the most significant geometric variable affecting rollover stability of trucks is radius of the horizontal curve. Length of the curve and superelevation also affect truck stability. Models which predict lateral acceleration experienced by a truck at point of curvature, midpoint of curve, and point of tangency were developed. Maximum lateral acceleration prediction models were also developed. The outputs of this research can be used as road safety audit tools to identify potential stability issues on curves and to design safe curves.]]></description>
      <pubDate>Tue, 17 Dec 2024 17:09:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/2407371</guid>
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