Pub Date : 2025-05-03DOI: 10.1016/j.treng.2025.100335
Jose Matute , Sarah Searcy , Ali Karimoddini
This paper explores the viability of automated shuttles for urban and suburban transportation through the Aggie Auto Shuttles pilot project conducted by researchers at North Carolina A&T State University in Greensboro, North Carolina, USA. While the long-term goal is high-driving automation operation, this study focuses on conditional driving automation with human drivers ready to take control. The design of the shuttles, including their sensor suite for navigating complex suburban environments, is detailed. This paper discusses the testing procedures conducted in a controlled environment that replicated driving conditions expected in the public road demonstration with passenger service to evaluate core functionalities like mapping, localization, object recognition, and motion planning and tracking. Then, the real-world pilot project is detailed, and the results are analyzed employing objective and subjective measures and approaches, highlighting the challenges and opportunities encountered. By examining findings from both controlled and real-world settings, a comprehensive assessment of the feasibility of deploying automated shuttles as part of an integrated public transportation system is offered, contributing to the discussion on the practicality and limitations of automated shuttles in urban and suburban environments.
本文通过位于美国北卡罗来纳州格林斯博罗的北卡罗来纳农工州立大学的研究人员开展的Aggie Auto shuttle试点项目，探讨了自动班车在城市和郊区交通中的可行性。虽然长期目标是高驾驶自动化操作，但本研究侧重于人类驾驶员准备控制的有条件驾驶自动化。穿梭车的设计，包括用于在复杂的郊区环境中导航的传感器套件，都是详细的。本文讨论了在受控环境中进行的测试过程，该环境复制了公共道路演示中预期的驾驶条件，并提供了客运服务，以评估地图、定位、目标识别、运动规划和跟踪等核心功能。然后，详细介绍了现实世界的试点项目，并采用客观和主观的测量和方法对结果进行了分析，突出了遇到的挑战和机遇。通过研究受控环境和现实环境的研究结果，本文对自动穿梭巴士作为综合公共交通系统的一部分部署的可行性进行了全面评估，并对自动穿梭巴士在城市和郊区环境中的实用性和局限性进行了讨论。
{"title":"Aggie Auto Shuttles: Technical Insights from the Public Road Demonstration","authors":"Jose Matute , Sarah Searcy , Ali Karimoddini","doi":"10.1016/j.treng.2025.100335","DOIUrl":"10.1016/j.treng.2025.100335","url":null,"abstract":"<div><div>This paper explores the viability of automated shuttles for urban and suburban transportation through the Aggie Auto Shuttles pilot project conducted by researchers at North Carolina A&T State University in Greensboro, North Carolina, USA. While the long-term goal is high-driving automation operation, this study focuses on conditional driving automation with human drivers ready to take control. The design of the shuttles, including their sensor suite for navigating complex suburban environments, is detailed. This paper discusses the testing procedures conducted in a controlled environment that replicated driving conditions expected in the public road demonstration with passenger service to evaluate core functionalities like mapping, localization, object recognition, and motion planning and tracking. Then, the real-world pilot project is detailed, and the results are analyzed employing objective and subjective measures and approaches, highlighting the challenges and opportunities encountered. By examining findings from both controlled and real-world settings, a comprehensive assessment of the feasibility of deploying automated shuttles as part of an integrated public transportation system is offered, contributing to the discussion on the practicality and limitations of automated shuttles in urban and suburban environments.</div></div>","PeriodicalId":34480,"journal":{"name":"Transportation Engineering","volume":"20 ","pages":"Article 100335"},"PeriodicalIF":0.0,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143936019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Physical Internet (PI) paradigm, which has gained attention in research and academia in recent years, leverages advanced logistics and interconnected networks to revolutionise the way goods are transported and delivered, thereby enhancing efficiency, reducing costs and delays, and minimising environmental impact. Within this system, PI-hubs function similarly to cross-docks, enabling the splitting of PI-containers into smaller modules for delivery through a network of interconnected hubs. This allows dynamic routing optimisation and efficient consolidation of PI-containers. However, the impact of system parameters and relevant uncertainties on the performance of this innovative logistics framework is still unclear. For this reason, this work proposes a robustness analysis to understand how the PI logistics framework is affected by the handling, consolidation, and processing of PI-containers at PI-hubs. To this end, the considered PI logistics system is represented via a mathematical programming model that determines the best allocation of PI-containers in an intermodal setting with different transportation modes. In doing so, four Key Performance Indicators (KPIs) are separately considered to investigate different aspects of the PI system’s performance, and the relevant robustness is assessed with respect to the PI-hub processing times and the number of modules per PI-container. In particular, a Global Sensitivity Analysis (GSA) is performed to evaluate, through a case study, the individual relevance of each input parameter on the resulting performance.
{"title":"Robustness evaluation of a physical internet-based intermodal logistic network","authors":"Federico Gallo , Alireza Shahedi , Angela Di Febbraro , Mahnam Saeednia , Nicola Sacco","doi":"10.1016/j.treng.2025.100333","DOIUrl":"10.1016/j.treng.2025.100333","url":null,"abstract":"<div><div>The Physical Internet (PI) paradigm, which has gained attention in research and academia in recent years, leverages advanced logistics and interconnected networks to revolutionise the way goods are transported and delivered, thereby enhancing efficiency, reducing costs and delays, and minimising environmental impact. Within this system, <em>PI-hubs</em> function similarly to cross-docks, enabling the splitting of PI-containers into smaller <em>modules</em> for delivery through a network of interconnected hubs. This allows dynamic routing optimisation and efficient consolidation of PI-containers. However, the impact of system parameters and relevant uncertainties on the performance of this innovative logistics framework is still unclear. For this reason, this work proposes a robustness analysis to understand how the PI logistics framework is affected by the handling, consolidation, and processing of PI-containers at PI-hubs. To this end, the considered PI logistics system is represented via a mathematical programming model that determines the best allocation of PI-containers in an intermodal setting with different transportation modes. In doing so, four Key Performance Indicators (KPIs) are separately considered to investigate different aspects of the PI system’s performance, and the relevant robustness is assessed with respect to the PI-hub processing times and the number of modules per PI-container. In particular, a Global Sensitivity Analysis (GSA) is performed to evaluate, through a case study, the individual relevance of each input parameter on the resulting performance.</div></div>","PeriodicalId":34480,"journal":{"name":"Transportation Engineering","volume":"20 ","pages":"Article 100333"},"PeriodicalIF":0.0,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143932094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-29DOI: 10.1016/j.treng.2025.100338
Federico Orsini , Giulia De Cet , Francesca Freuli , Leandro L. Di Stasi , Mariaelena Tagliabue , Massimiliano Gastaldi , Riccardo Rossi
Manage-How-You-Drive (MHYD) is an innovative usage-based insurance scheme where drivers are charged premiums based on their safety performance, incorporating real-time coaching programs to provide drivers with contingent feedback, nudging them to drive more safely. As limited research exists on these novel schemes, this study aims to confirm their effectiveness, by expanding the sample size and the scope of analysis from a previous study by the authors, and to specifically focus on the retention of improved behavior and the impact of driver characteristics and feedback types on retention.
A driving simulator experiment involving 100 drivers was used to test four feedback systems, with different modality (auditory vs. visual) and valence (i.e., pleasantness of the feedback: positive vs. negative), based on the occurrence of Elevated Gravitational-Force Events (EGFEs, i.e., harsh acceleration/deceleration events). Drivers completed three trials, spaced four weeks apart. The first trial served as a baseline without any feedback, in the second trial one of the feedback systems was presented, and the third trial had no feedback. Program effectiveness and retention were assessed based on EGFE occurrences and mean acceleration/deceleration. Its indirect influence on speeding, tailgating, and lateral control was investigated to assess potential additional enduring effects on safety performance.
Drivers, especially those identified as “aggressive” during the baseline trial, not only significantly benefited from using the coaching program, but were also able to at least partially retain such benefits in terms of acceleration/deceleration, speeding and tailgating, irrespective of feedback type. These findings highlight the potential practical advantages of MHYD real-time coaching systems for road safety.
{"title":"Real-time coaching programs for Manage-How-You-Drive insurance schemes: Analysis of retention after feedback removal","authors":"Federico Orsini , Giulia De Cet , Francesca Freuli , Leandro L. Di Stasi , Mariaelena Tagliabue , Massimiliano Gastaldi , Riccardo Rossi","doi":"10.1016/j.treng.2025.100338","DOIUrl":"10.1016/j.treng.2025.100338","url":null,"abstract":"<div><div>Manage-How-You-Drive (MHYD) is an innovative usage-based insurance scheme where drivers are charged premiums based on their safety performance, incorporating real-time coaching programs to provide drivers with contingent feedback, nudging them to drive more safely. As limited research exists on these novel schemes, this study aims to confirm their effectiveness, by expanding the sample size and the scope of analysis from a previous study by the authors, and to specifically focus on the retention of improved behavior and the impact of driver characteristics and feedback types on retention.</div><div>A driving simulator experiment involving 100 drivers was used to test four feedback systems, with different modality (auditory vs. visual) and valence (i.e., pleasantness of the feedback: positive vs. negative), based on the occurrence of Elevated Gravitational-Force Events (EGFEs, i.e., harsh acceleration/deceleration events). Drivers completed three trials, spaced four weeks apart. The first trial served as a baseline without any feedback, in the second trial one of the feedback systems was presented, and the third trial had no feedback. Program effectiveness and retention were assessed based on EGFE occurrences and mean acceleration/deceleration. Its indirect influence on speeding, tailgating, and lateral control was investigated to assess potential additional enduring effects on safety performance.</div><div>Drivers, especially those identified as “aggressive” during the baseline trial, not only significantly benefited from using the coaching program, but were also able to at least partially retain such benefits in terms of acceleration/deceleration, speeding and tailgating, irrespective of feedback type. These findings highlight the potential practical advantages of MHYD real-time coaching systems for road safety.</div></div>","PeriodicalId":34480,"journal":{"name":"Transportation Engineering","volume":"20 ","pages":"Article 100338"},"PeriodicalIF":0.0,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143935920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-22DOI: 10.1016/j.treng.2025.100336
Hyun-Su Park, Byeong-Su Kim, Seong-Wan Park
The resilient modulus of the aggregate base material is crucial in mechanical pavement design. The resilient modulus is affected not only by the stress state but also by the moisture state, which must be considered during modeling to properly estimate the resilient modulus. Regarding the moisture state, the suction stress as a stress state variable accounts for the effect of suction and saturation can be incorporated into the resilient modulus model. In this study, the effect of suction stress on the resilient modulus was investigated, and the behavior of suction stress was considered based on the concept of average skeletal stress and independent stress state variables to estimate the resilient modulus. The results revealed that the established model appropriately estimates the resilient modulus of the aggregate base materials and that suction stress affects the resilient modulus independently.
{"title":"Influence of suction stress on the resilient modulus model for unsaturated aggregate base","authors":"Hyun-Su Park, Byeong-Su Kim, Seong-Wan Park","doi":"10.1016/j.treng.2025.100336","DOIUrl":"10.1016/j.treng.2025.100336","url":null,"abstract":"<div><div>The resilient modulus of the aggregate base material is crucial in mechanical pavement design. The resilient modulus is affected not only by the stress state but also by the moisture state, which must be considered during modeling to properly estimate the resilient modulus. Regarding the moisture state, the suction stress as a stress state variable accounts for the effect of suction and saturation can be incorporated into the resilient modulus model. In this study, the effect of suction stress on the resilient modulus was investigated, and the behavior of suction stress was considered based on the concept of average skeletal stress and independent stress state variables to estimate the resilient modulus. The results revealed that the established model appropriately estimates the resilient modulus of the aggregate base materials and that suction stress affects the resilient modulus independently.</div></div>","PeriodicalId":34480,"journal":{"name":"Transportation Engineering","volume":"20 ","pages":"Article 100336"},"PeriodicalIF":0.0,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143879263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study focuses on the dynamics of the train-track-bridge interaction system, specifically addressing the challenges posed by saturated ballasted tracks due to insufficient drainage during extreme flooding events. A full-scale sleeper-ballast experiment is first conducted using instrumented impact hammer excitation and a minimization algorithm, which characterizes the dynamic behaviour of sleeper-ballast interaction at varying water levels (0–35 cm). The ballast stiffness and damping are condensed into a single parameter using the Guyan condensation scheme, revealing increased damping and reduced stiffness with rising water levels. The condensed parameters are then used in the two-dimensional Train-Track-Bridge-Dynamic-Interaction-Systems (TTBDIS), which are validated with published literature to carry out the parametric studies. The dynamic response of the interaction system is influenced by a complex interplay of factors, including the inverse relationship between track stiffness and damping, an aspect that has not been previously investigated. Findings indicate that lower water levels are critical for dynamic amplification on longer-span bridges, while higher water levels are critical for shorter spans. Critical speeds emerge when the bridge’s fundamental frequency aligns with higher harmonics of dominant and driving frequencies, causing dynamic responses that exceed safety limits. The general dominance weight analysis further revealed that the bridge’s mass is the most significant factor, followed by track damping, span length, track stiffness, and train speed. The findings are crucial to understanding the behaviour of railway bridges during extreme flooding, helping railway authorities mitigate their adverse impacts, making them more climate resilient, and improving design and maintenance regimes.
{"title":"Dynamics responses of railway bridges influenced by flooded ballasted tracks subjected to high-speed trains","authors":"Naveen Kumar Kedia , Ratabhat Wangtawesap , Chayut Ngamkhanong","doi":"10.1016/j.treng.2025.100334","DOIUrl":"10.1016/j.treng.2025.100334","url":null,"abstract":"<div><div>This study focuses on the dynamics of the train-track-bridge interaction system, specifically addressing the challenges posed by saturated ballasted tracks due to insufficient drainage during extreme flooding events. A full-scale sleeper-ballast experiment is first conducted using instrumented impact hammer excitation and a minimization algorithm, which characterizes the dynamic behaviour of sleeper-ballast interaction at varying water levels (0–35 cm). The ballast stiffness and damping are condensed into a single parameter using the Guyan condensation scheme, revealing increased damping and reduced stiffness with rising water levels. The condensed parameters are then used in the two-dimensional Train-Track-Bridge-Dynamic-Interaction-Systems (TTBDIS), which are validated with published literature to carry out the parametric studies. The dynamic response of the interaction system is influenced by a complex interplay of factors, including the inverse relationship between track stiffness and damping, an aspect that has not been previously investigated. Findings indicate that lower water levels are critical for dynamic amplification on longer-span bridges, while higher water levels are critical for shorter spans. Critical speeds emerge when the bridge’s fundamental frequency aligns with higher harmonics of dominant and driving frequencies, causing dynamic responses that exceed safety limits. The general dominance weight analysis further revealed that the bridge’s mass is the most significant factor, followed by track damping, span length, track stiffness, and train speed. The findings are crucial to understanding the behaviour of railway bridges during extreme flooding, helping railway authorities mitigate their adverse impacts, making them more climate resilient, and improving design and maintenance regimes.</div></div>","PeriodicalId":34480,"journal":{"name":"Transportation Engineering","volume":"20 ","pages":"Article 100334"},"PeriodicalIF":0.0,"publicationDate":"2025-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143873762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The widespread use of asphalt mixtures has increased the need for aggregates. Researchers are exploring alternative materials, such as rubber powder, which is commonly used to modify bitumen. In this research, the fine aggregates were replaced with different contents of rubber powder (1, 3, and 5 % by fine aggregate weight). Also, different contents of Nano-TiO₂ (0.3, 0.6, 0.9, and 1.2 % by bitumen weight) was used to improve the behavior of bitumen. Rutting, Fatigue and moisture susceptibility were investigated in these samples. The test results showed that although the use of rubber powder instead of aggregates has reduced the rutting resistance of the asphalt mixture by about 50 %, fatigue resistance by about 40 %, and moisture susceptibility by about 8 %, the use of Nano-TiO₂ can compensate. The most optimal condition from the technical and economic standpoint is to manufacture an asphalt mixture containing 3 % rubber powder and 0.9 % Nano-TiO2, in which the values of rutting, fatigue, and moisture susceptibility are approximately equal to that of the control specimen. This condition leads to a 3 % reduction in the use of natural aggregates compared to the control mixture.
{"title":"Sustainable Nano-TiO2 modified asphalt with fine aggregate replacement using rubber powder","authors":"Gholamali Shafabakhsh , Mostafa Sadeghnejad , Pouya Mahmoudi , Roya Ebrahimnia","doi":"10.1016/j.treng.2025.100332","DOIUrl":"10.1016/j.treng.2025.100332","url":null,"abstract":"<div><div>The widespread use of asphalt mixtures has increased the need for aggregates. Researchers are exploring alternative materials, such as rubber powder, which is commonly used to modify bitumen. In this research, the fine aggregates were replaced with different contents of rubber powder (1, 3, and 5 % by fine aggregate weight). Also, different contents of Nano-TiO₂ (0.3, 0.6, 0.9, and 1.2 % by bitumen weight) was used to improve the behavior of bitumen. Rutting, Fatigue and moisture susceptibility were investigated in these samples. The test results showed that although the use of rubber powder instead of aggregates has reduced the rutting resistance of the asphalt mixture by about 50 %, fatigue resistance by about 40 %, and moisture susceptibility by about 8 %, the use of Nano-TiO₂ can compensate. The most optimal condition from the technical and economic standpoint is to manufacture an asphalt mixture containing 3 % rubber powder and 0.9 % Nano-TiO<sub>2</sub>, in which the values of rutting, fatigue, and moisture susceptibility are approximately equal to that of the control specimen. This condition leads to a 3 % reduction in the use of natural aggregates compared to the control mixture.</div></div>","PeriodicalId":34480,"journal":{"name":"Transportation Engineering","volume":"20 ","pages":"Article 100332"},"PeriodicalIF":0.0,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study introduces an innovative battery thermal management system (BTMS) that integrates liquid cooling, U-type heat pipes, and composite phase change materials (CPCM) to enhance thermal efficiency. Utilizing a transient thermo-fluid simulation model, the thermal performance of the proposed advanced BTMS for lithium-ion batteries (LIBs) is evaluated under various operational conditions. The model's predictions are validated against experimental data, ensuring reliability and robustness. The study examines two BTMS configurations: liquid cooling and a hybrid system combining active liquid cooling with passive CPCM and heat pipes. These configurations are examined under different thermal loads to assess their effectiveness. The study investigates the influence of liquid inlet velocity and ambient temperature on the maximum temperature () and maximum temperature difference () within the battery module, critical metrics affecting battery efficiency and lifespan. Additionally, the study evaluates the driving cycle and pumping power requirements, comparing the BTMS with alternative designs, demonstrating that the proposed system efficiently dissipates heat while requiring lower pumping power. Key findings include the superior performance of hybrid cooling, which reduces by 9.32 K at 293 K and maintains below 5 K. The hybrid BTMS achieves similar thermal performance with 53 % less power than liquid cooling. During active cooling failures, passive cooling with CPCM and heat pipes effectively removes heat, maintaining an optimal temperature range with passive BTMS peaking at 308.79 K and hybrid BTMS below 302 K. Under real-world driving conditions, the hybrid BTMS lowers by 8.2 K and stabilizes temperature fluctuations.
{"title":"Efficient BTMS for lithium-ion batteries: A study on PCM/Metal foam, heat pipe, and microchannel integration","authors":"Soheil Saeedipour , Ayat Gharehghani , Moeed Rabiei , Amin Mahmoudzadeh Andwari , Sadegh Mehranfar , Carlos Mico Reche , Navid Rabiei","doi":"10.1016/j.treng.2025.100330","DOIUrl":"10.1016/j.treng.2025.100330","url":null,"abstract":"<div><div>This study introduces an innovative battery thermal management system (BTMS) that integrates liquid cooling, U-type heat pipes, and composite phase change materials (CPCM) to enhance thermal efficiency. Utilizing a transient thermo-fluid simulation model, the thermal performance of the proposed advanced BTMS for lithium-ion batteries (LIBs) is evaluated under various operational conditions. The model's predictions are validated against experimental data, ensuring reliability and robustness. The study examines two BTMS configurations: liquid cooling and a hybrid system combining active liquid cooling with passive CPCM and heat pipes. These configurations are examined under different thermal loads to assess their effectiveness. The study investigates the influence of liquid inlet velocity and ambient temperature on the maximum temperature (<span><math><msub><mi>T</mi><mrow><mi>m</mi><mi>a</mi><mi>x</mi></mrow></msub></math></span>) and maximum temperature difference (<span><math><mrow><mstyle><mi>Δ</mi></mstyle><msub><mi>T</mi><mrow><mi>m</mi><mi>a</mi><mi>x</mi></mrow></msub></mrow></math></span>) within the battery module, critical metrics affecting battery efficiency and lifespan. Additionally, the study evaluates the driving cycle and pumping power requirements, comparing the BTMS with alternative designs, demonstrating that the proposed system efficiently dissipates heat while requiring lower pumping power. Key findings include the superior performance of hybrid cooling, which reduces <span><math><msub><mi>T</mi><mrow><mi>m</mi><mi>a</mi><mi>x</mi></mrow></msub></math></span> by 9.32 K at 293 K and maintains <span><math><mrow><mstyle><mi>Δ</mi></mstyle><msub><mi>T</mi><mrow><mi>m</mi><mi>a</mi><mi>x</mi></mrow></msub></mrow></math></span> below 5 K. The hybrid BTMS achieves similar thermal performance with 53 % less power than liquid cooling. During active cooling failures, passive cooling with CPCM and heat pipes effectively removes heat, maintaining an optimal temperature range with passive BTMS peaking at 308.79 K and hybrid BTMS below 302 K. Under real-world driving conditions, the hybrid BTMS lowers <span><math><msub><mi>T</mi><mrow><mi>m</mi><mi>a</mi><mi>x</mi></mrow></msub></math></span> by 8.2 K and stabilizes temperature fluctuations.</div></div>","PeriodicalId":34480,"journal":{"name":"Transportation Engineering","volume":"20 ","pages":"Article 100330"},"PeriodicalIF":0.0,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143835009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-11DOI: 10.1016/j.treng.2025.100331
Ionuţ Dragoş Moldovan , Mohammad Jawed Roshan , Miguel Azenha , António Gomes Correia
The bender element (BE) test is widely employed in geotechnical engineering for measuring the shear wave velocity () and, consequently, the small-strain shear modulus (), due to its ease of application, integration into geotechnical devices, and effectiveness in real-world projects. However, signal distortion, primarily caused by shear and compression wave interference, remains a significant challenge, leading to unreliable measurements. This study, conducted as part of the CEN-DynaGeo and INTENT projects, introduces 3D-printed dissipation boundaries designed to mitigate compression wave interference and enhance signal clarity. Three dissipation boundary shapes including rings, spikes, and vertical strips were evaluated in a custom-designed vertical compression acrylic cell equipped with bender elements. The shapes were designed based on the numerical modeling of the BE experiment, conducted using the FreeHyTE software, which employs hybrid-Trefftz finite elements. Experimental results demonstrated that all dissipation boundaries effectively attenuated the compression wave peaks, with efficiencies depending on their shapes. Under vertical stress of 50 kPa and input frequency of 2 kHz in specimens with a void ratio of 0.85, compression wave peak reductions of 60 %, 46 %, and 19.9 % were observed for the ring, spike, and vertical strip boundaries, respectively. The proposed dissipation boundary technique offers a novel solution to improve the reliability of bender element testing in geotechnical applications.
{"title":"Dissipation boundaries for bender element experiments on geomaterials based on experimental and computational models","authors":"Ionuţ Dragoş Moldovan , Mohammad Jawed Roshan , Miguel Azenha , António Gomes Correia","doi":"10.1016/j.treng.2025.100331","DOIUrl":"10.1016/j.treng.2025.100331","url":null,"abstract":"<div><div>The bender element (BE) test is widely employed in geotechnical engineering for measuring the shear wave velocity (<span><math><msub><mi>V</mi><mi>s</mi></msub></math></span>) and, consequently, the small-strain shear modulus (<span><math><msub><mi>G</mi><mn>0</mn></msub></math></span>), due to its ease of application, integration into geotechnical devices, and effectiveness in real-world projects. However, signal distortion, primarily caused by shear and compression wave interference, remains a significant challenge, leading to unreliable measurements. This study, conducted as part of the CEN-DynaGeo and INTENT projects, introduces 3D-printed dissipation boundaries designed to mitigate compression wave interference and enhance signal clarity. Three dissipation boundary shapes including rings, spikes, and vertical strips were evaluated in a custom-designed vertical compression acrylic cell equipped with bender elements. The shapes were designed based on the numerical modeling of the BE experiment, conducted using the FreeHyTE software, which employs hybrid-Trefftz finite elements. Experimental results demonstrated that all dissipation boundaries effectively attenuated the compression wave peaks, with efficiencies depending on their shapes. Under vertical stress of 50 kPa and input frequency of 2 kHz in specimens with a void ratio of 0.85, compression wave peak reductions of 60 %, 46 %, and 19.9 % were observed for the ring, spike, and vertical strip boundaries, respectively. The proposed dissipation boundary technique offers a novel solution to improve the reliability of bender element testing in geotechnical applications.</div></div>","PeriodicalId":34480,"journal":{"name":"Transportation Engineering","volume":"20 ","pages":"Article 100331"},"PeriodicalIF":0.0,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143839184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Advancements in computing power over recent decades have facilitated the widespread adoption of computationally intensive traffic simulation models, driving a notable increase in the use of large-scale dynamic traffic assignment (DTA) models. These models rely on time-dependent origin-destination (TDOD) traffic demands, commonly referred to as profiled traffic demands, which capture both the spatial distribution of traffic at the origin-destination (OD) level and its temporal variation. While optimisation solutions are commonly employed to estimate profiled origin-destination (OD) traffic demand for small networks by reconciling observed and simulated traffic counts at selected locations, their application to large networks poses significant challenges. Using the Greater Adelaide area as a case study, this paper examines these challenges and demonstrates the successful implementation of a customised OD traffic demand profiling approach, based on zone-aggregate traffic profiles at the departure and arrival zones.
{"title":"A heuristic approach to time-dependent origin-destination traffic demand estimation for the development of large-scale dynamic traffic assignment models","authors":"Keyvan Pourhassan , Timothy Lim , Stephen Payne , Sekhar Somenahalli","doi":"10.1016/j.treng.2025.100328","DOIUrl":"10.1016/j.treng.2025.100328","url":null,"abstract":"<div><div>Advancements in computing power over recent decades have facilitated the widespread adoption of computationally intensive traffic simulation models, driving a notable increase in the use of large-scale dynamic traffic assignment (DTA) models. These models rely on time-dependent origin-destination (TDOD) traffic demands, commonly referred to as profiled traffic demands, which capture both the spatial distribution of traffic at the origin-destination (OD) level and its temporal variation. While optimisation solutions are commonly employed to estimate profiled origin-destination (OD) traffic demand for small networks by reconciling observed and simulated traffic counts at selected locations, their application to large networks poses significant challenges. Using the Greater Adelaide area as a case study, this paper examines these challenges and demonstrates the successful implementation of a customised OD traffic demand profiling approach, based on zone-aggregate traffic profiles at the departure and arrival zones.</div></div>","PeriodicalId":34480,"journal":{"name":"Transportation Engineering","volume":"20 ","pages":"Article 100328"},"PeriodicalIF":0.0,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143859143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Understanding road traffic crashes' spatial and temporal dynamics is essential for targeted safety interventions. Prior studies often rely on spatial units like junctions, road segments, traffic analysis zones, or broad urban-rural classifications. However, this dichotomy limits insights into crash patterns along the urban-periphery continuum. This study analyzes three years of georeferenced crash data from Addis Ababa using equally spaced radial zones from the crash center as spatial units. A combination of descriptive statistics, nonmetric multidimensional scaling, and multinomial logistic regression was employed to investigate spatial and temporal crash patterns, while the Knox test was applied to identify statistically significant spatio-temporal clustering. Results indicate minor injury crashes are more frequent in inner-city, whereas fatal and serious crashes dominate peripheral zones. Nighttime crashes, particularly in late evening hours, are more lethal in inner and intermediate zones, while fatal crashes in peripheral areas primarily occur during the daytime. Vehicle-pedestrian collisions pose the highest risk, followed by rear-end, sideswipe, and head-on crashes. Fatal and serious crashes are significantly more likely on weekends and at night, with severity increasing with distance from the city center. The Knox test confirms strong spatiotemporal clustering of fatal crashes within a two-week window and 100m-150 m range at 99.9 % confidence. For spatial ranges of 200m-300 m, clusters persist for 59–71 days. Clusters at 500m-1250 m thresholds emerge within 13–27 days, with 1000m-1250 m ranges exhibiting similar patterns. The findings highlight the limitations of the urbanrural dichotomy and emphasize alternative zoning methods for improved spatial and temporal analysis in road safety.
{"title":"Spatio-temporal analysis of road traffic crashes by severity","authors":"Wondwossen Taddesse Gedamu , Uwe Plank-Wiedenbeck , Bikila Teklu Wodajo","doi":"10.1016/j.treng.2025.100327","DOIUrl":"10.1016/j.treng.2025.100327","url":null,"abstract":"<div><div>Understanding road traffic crashes' spatial and temporal dynamics is essential for targeted safety interventions. Prior studies often rely on spatial units like junctions, road segments, traffic analysis zones, or broad urban-rural classifications. However, this dichotomy limits insights into crash patterns along the urban-periphery continuum. This study analyzes three years of georeferenced crash data from Addis Ababa using equally spaced radial zones from the crash center as spatial units. A combination of descriptive statistics, nonmetric multidimensional scaling, and multinomial logistic regression was employed to investigate spatial and temporal crash patterns, while the Knox test was applied to identify statistically significant spatio-temporal clustering. Results indicate minor injury crashes are more frequent in inner-city, whereas fatal and serious crashes dominate peripheral zones. Nighttime crashes, particularly in late evening hours, are more lethal in inner and intermediate zones, while fatal crashes in peripheral areas primarily occur during the daytime. Vehicle-pedestrian collisions pose the highest risk, followed by rear-end, sideswipe, and head-on crashes. Fatal and serious crashes are significantly more likely on weekends and at night, with severity increasing with distance from the city center. The Knox test confirms strong spatiotemporal clustering of fatal crashes within a two-week window and 100m-150 m range at 99.9 % confidence. For spatial ranges of 200m-300 m, clusters persist for 59–71 days. Clusters at 500m-1250 m thresholds emerge within 13–27 days, with 1000m-1250 m ranges exhibiting similar patterns. The findings highlight the limitations of the urbanrural dichotomy and emphasize alternative zoning methods for improved spatial and temporal analysis in road safety.</div></div>","PeriodicalId":34480,"journal":{"name":"Transportation Engineering","volume":"20 ","pages":"Article 100327"},"PeriodicalIF":0.0,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143807371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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