Transportation Research Record: Journal of the Transportation Research Board最新文献

{"title":"Tram-Pedestrian Collision Modeling Using Experimental Data—Its Validation, Repeatability, and Challenges: A Pilot Study","authors":"H. Purs, Martin Kuklik, Frantisek Lopot, P. Kubový, K. Jelen, Tommi Tikkanen, Roman Ježdík, Lukas Fara, Luboš Tomšovský","doi":"10.1177/03611981231225432","DOIUrl":"https://doi.org/10.1177/03611981231225432","url":null,"abstract":"To satisfy the needs of growing urban populations, mitigate the impacts of climate change, and improve the environmental conditions and quality of life in cities, there has been an increasing demand for public transport, especially effective and economically beneficial trams. As a consequence, the issue of pedestrians’ safety has become more important because of a higher risk of tram-pedestrian collisions. The article is focused on the development of a computational model that can accurately simulate such collisions, and its challenges and limitations. Experiments were conducted using various types of trams, different impact speeds, and an anthropomorphic test device (dummy). Computational models of the tram front ends were created based on CAD geometry supplied by VÚKV a.s. The finite-element mesh itself used a combination of 1D, 2D, and 3D elements. Depending on the shape of the individual components, TRIA, QUAD, HEX, PENTA, and TETRA elements were used for modeling. The results showed that the consequences of these collisions are sensitive to small differences in the posture of the dummies. Therefore, it is difficult to identify a generally more pedestrian-friendly shape for trams using the dummy-tram crash test method.","PeriodicalId":509035,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":" 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139790149","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}

{"title":"Tram-Pedestrian Collision Modeling Using Experimental Data—Its Validation, Repeatability, and Challenges: A Pilot Study","authors":"H. Purs, Martin Kuklik, Frantisek Lopot, P. Kubový, K. Jelen, Tommi Tikkanen, Roman Ježdík, Lukas Fara, Luboš Tomšovský","doi":"10.1177/03611981231225432","DOIUrl":"https://doi.org/10.1177/03611981231225432","url":null,"abstract":"To satisfy the needs of growing urban populations, mitigate the impacts of climate change, and improve the environmental conditions and quality of life in cities, there has been an increasing demand for public transport, especially effective and economically beneficial trams. As a consequence, the issue of pedestrians’ safety has become more important because of a higher risk of tram-pedestrian collisions. The article is focused on the development of a computational model that can accurately simulate such collisions, and its challenges and limitations. Experiments were conducted using various types of trams, different impact speeds, and an anthropomorphic test device (dummy). Computational models of the tram front ends were created based on CAD geometry supplied by VÚKV a.s. The finite-element mesh itself used a combination of 1D, 2D, and 3D elements. Depending on the shape of the individual components, TRIA, QUAD, HEX, PENTA, and TETRA elements were used for modeling. The results showed that the consequences of these collisions are sensitive to small differences in the posture of the dummies. Therefore, it is difficult to identify a generally more pedestrian-friendly shape for trams using the dummy-tram crash test method.","PeriodicalId":509035,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":"8 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139849973","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}

{"title":"Adopting the Performance Margin in Horizontal Curve Design","authors":"Troy Jaisohn Kim, John B. Ferris","doi":"10.1177/03611981241229090","DOIUrl":"https://doi.org/10.1177/03611981241229090","url":null,"abstract":"A vehicle negotiating a curve experiences a centripetal force that is partially supplied by the tire–pavement friction. The American Association of State Highway and Transportation Officials’ design handbook, A Policy on Geometric Design of Highways and Streets (“Green Book”), dictates the design of horizontal curve segments according to the side friction (demand) factor, which is a fraction of the available friction used during a maneuver. However, the Green Book casts the side friction factor not as a measure of tire–pavement friction but as a measure of lateral acceleration. In this way, the Green Book conflates these independent concepts (tire–pavement friction versus lateral acceleration). It is shown in this work that keeping these curve design parameters independent has meaningful benefits. A rigorous mathematical clarification of the differences among the side friction (demand) factor, lateral acceleration, and coefficient of friction is developed. It is shown that changing the coefficient of friction affects the side friction factor, but the opposite is not necessarily true. An alternate metric is proposed, the performance margin [Formula: see text], that has several advantages for assessing friction margins. Currently, horizontal curves are designed only with a lateral friction reserve. Excluding longitudinal dynamics may not be realistic given the manner in which drivers react in limit handling maneuvers. The [Formula: see text] accounts for both bidirectional dynamics and road geometry, and highlights regions where the Green Book’s standards are inconsistent with vehicle performance capabilities. The work concludes by posing recommendations aimed at implementing the [Formula: see text] in future Green Book editions.","PeriodicalId":509035,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":"48 11-12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139850290","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}

{"title":"Reflections on the Role of Researchers in Shaping the Ideas that Shape Transportation","authors":"Susan Handy","doi":"10.1177/03611981231222861","DOIUrl":"https://doi.org/10.1177/03611981231222861","url":null,"abstract":"","PeriodicalId":509035,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":"141 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139794352","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}

{"title":"Route Optimization of Hazardous Material (Hazmat) Transportation with Risk Equity and Time-Varying Risk","authors":"Liping Liu, X. Gan, Qing Wu, Zhengwei Sun","doi":"10.1177/03611981231223186","DOIUrl":"https://doi.org/10.1177/03611981231223186","url":null,"abstract":"This paper strives for route optimization of hazardous material (hazmat) for given probabilities and consequences. We aim to not only develop a model to determine the route with the least total risk and cost, but also pursue risk equity from three perspectives of government, enterprises, and society in the route optimization. Specifically, this paper reduces the differences of population exposure risk among road segments by using the threshold setting method and decreases the differences of environmental risk by minimizing the risk compensation cost caused by the additional environmental risk exceeding its average for each road segment. In addition, this paper analyzes the impact of the time-varying characteristics of risk and risk equity and proposes a multi-objective route optimization model which considers the minimization of total risk, cost, and risk differences under time-varying conditions. Finally, the ε-constraint method and an improved genetic algorithm are used to optimize the model, which is applied to a case study involving hazardous materials transportation route optimization in Shanghai, China. The resulting analyses indicate that risk equity can be improved by setting a proper threshold to acquire feasible paths and by minimizing the compensation cost to control the differences of environmental risk. Considering variance of time in the route optimization may lead to a route with lower risk and better risk equity.","PeriodicalId":509035,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":"38 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139852766","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}

{"title":"Modeling Urban Railway Passengers’ Willingness to Wait Based on Latent Class Analysis","authors":"Hwan-Seung Lee, Ho-Chan Kwak, Eun-Seo Han, Ho-Chul Park","doi":"10.1177/03611981231225641","DOIUrl":"https://doi.org/10.1177/03611981231225641","url":null,"abstract":"Overcrowding in confined spaces, like inside trains, is a social issue that, in the long-term, could lead to accidents. To alleviate congestion in trains, a reduction in train headways is planned, made possible by technological advances such as the introduction of advanced autonomous trains (e.g., 60-s headway). However, simply reducing a train’s headway may be challenging because this does not consider the travel behavior of passengers who engage in the disruptive act of excessively boarding trains, thereby causing delays in their departure. Furthermore, the behavior of passengers may vary depending on an individual’s latent preferences, however, there is insufficient research that reflects these latent preferences. In this study, a survey was conducted with 971 urban rail passengers in the Seoul Metropolitan Area of Korea to identify their latent preferences using latent class analysis, resulting in a four-type classification: a congestion avoidance type, a time-sensitive type, a subway-preference type, and a type that does not prefer public transportation. Based on this, willingness to wait (WTW; i.e., waiting for the next less crowded train to reduce passenger discomfort) according to their latent preferences, was calculated. WTW was found to increase as the headway of the train was reduced. Choice modeling was conducted based on variables, including socioeconomic variables, to suggest effects related to WTW. The results indicated demand dispersion effects according to the headway reduction at peak times for various types of people. This study’s findings could be utilized to offer less crowded and safer train operations.","PeriodicalId":509035,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":"98 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139793861","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}

{"title":"Comparative Analysis of Different Accessibility to Transportation Stations Gap Indices","authors":"Hiba Algaidan, Rouzbeh Shad, Hussein Attya","doi":"10.1177/03611981231225643","DOIUrl":"https://doi.org/10.1177/03611981231225643","url":null,"abstract":"In this paper, an analytical methodology is presented for computing the accessibility of transportation stations gap (ATSG) using differences between the accessibility indices for the public and private stations within a certain travel time thresholds in the city of Mashhad, Iran. Analyzing the conceptual differences among current modal accessibility methods of transportation stations can help to evaluate ATSG more accurately and minimizes the number of gaps between the private and public transportation stations. To address this need, we conducted a comparative analysis of the different accessibility methods and developed a novel approach based on spatio-temporal analysis. Three accessibility models were analyzed—contour (cumulative) (CN), potential access (PA), and gravity metric (GM)—considering three spatial factors (land use, transportation infrastructure, and population densities). Temporal factors including three travel time thresholds (3, 15, and 60 min) and three peak time periods (morning, noon, and afternoon) were analyzed to calculate the ATSG values for the private and public modes. Resulted ATSG values indicated superior accessibility for private cars in all three time thresholds applying three methods. However, our subsequent in-depth analysis of results determined that the ATSG values fluctuated as the time thresholds changed in the CN and PA methods. In the GM method, these values systematically increased as the time thresholds increased. The consequences of the GM method were more in line with reality and showed higher accuracy compared with others.","PeriodicalId":509035,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":" 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139792697","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}

{"title":"Route Optimization of Hazardous Material (Hazmat) Transportation with Risk Equity and Time-Varying Risk","authors":"Liping Liu, X. Gan, Qing Wu, Zhengwei Sun","doi":"10.1177/03611981231223186","DOIUrl":"https://doi.org/10.1177/03611981231223186","url":null,"abstract":"This paper strives for route optimization of hazardous material (hazmat) for given probabilities and consequences. We aim to not only develop a model to determine the route with the least total risk and cost, but also pursue risk equity from three perspectives of government, enterprises, and society in the route optimization. Specifically, this paper reduces the differences of population exposure risk among road segments by using the threshold setting method and decreases the differences of environmental risk by minimizing the risk compensation cost caused by the additional environmental risk exceeding its average for each road segment. In addition, this paper analyzes the impact of the time-varying characteristics of risk and risk equity and proposes a multi-objective route optimization model which considers the minimization of total risk, cost, and risk differences under time-varying conditions. Finally, the ε-constraint method and an improved genetic algorithm are used to optimize the model, which is applied to a case study involving hazardous materials transportation route optimization in Shanghai, China. The resulting analyses indicate that risk equity can be improved by setting a proper threshold to acquire feasible paths and by minimizing the compensation cost to control the differences of environmental risk. Considering variance of time in the route optimization may lead to a route with lower risk and better risk equity.","PeriodicalId":509035,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":" 51","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139792884","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}

{"title":"Comparative Analysis of Different Accessibility to Transportation Stations Gap Indices","authors":"Hiba Algaidan, Rouzbeh Shad, Hussein Attya","doi":"10.1177/03611981231225643","DOIUrl":"https://doi.org/10.1177/03611981231225643","url":null,"abstract":"In this paper, an analytical methodology is presented for computing the accessibility of transportation stations gap (ATSG) using differences between the accessibility indices for the public and private stations within a certain travel time thresholds in the city of Mashhad, Iran. Analyzing the conceptual differences among current modal accessibility methods of transportation stations can help to evaluate ATSG more accurately and minimizes the number of gaps between the private and public transportation stations. To address this need, we conducted a comparative analysis of the different accessibility methods and developed a novel approach based on spatio-temporal analysis. Three accessibility models were analyzed—contour (cumulative) (CN), potential access (PA), and gravity metric (GM)—considering three spatial factors (land use, transportation infrastructure, and population densities). Temporal factors including three travel time thresholds (3, 15, and 60 min) and three peak time periods (morning, noon, and afternoon) were analyzed to calculate the ATSG values for the private and public modes. Resulted ATSG values indicated superior accessibility for private cars in all three time thresholds applying three methods. However, our subsequent in-depth analysis of results determined that the ATSG values fluctuated as the time thresholds changed in the CN and PA methods. In the GM method, these values systematically increased as the time thresholds increased. The consequences of the GM method were more in line with reality and showed higher accuracy compared with others.","PeriodicalId":509035,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":"290 3-4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139852283","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}

{"title":"Advancing Shallow Tunnel Construction in Soft Ground: The Pipe-Umbrella Box Jacking Method","authors":"Xi Jiang, Xuehui Zhang, Xiao Zhang, Luyuan Long, Yun Bai, Baoshan Huang","doi":"10.1177/03611981231225430","DOIUrl":"https://doi.org/10.1177/03611981231225430","url":null,"abstract":"The development of modern cities has often led to increased traffic congestion and limited usable space. One effective solution to these problems is to construct roadway tunnels, which can expand urban space and alleviate traffic congestion. However, building large underpass tunnels in urban areas, especially in soft ground, presents technical challenges owing to its extensive environmental disturbance. The pipe-umbrella box jacking method offers a promising solution to these challenges as this method does not require breaking the ground from the surface or disrupting surface traffic. This study reviews the key techniques of the pipe-umbrella box jacking method for constructing large rectangular tunnels with small burial depths in soft ground. The study focuses on three main technical issues: pipe umbrella installation, soil face excavation, and box jacking control. Furthermore, two tunnel projects in Shanghai, China, are presented as case studies to showcase the construction challenges and countermeasures during box jacking tunneling with pipe-umbrella. Practical construction experience has revealed that the installation of the pipe umbrella before box jacking serves as an effective method of ground pre-support. However, its performance can be influenced by factors such as pipe installation deviation and inter-pipe connection design. Both open-face steel grid extrusion (SGE) shields and closed-face earth pressure balanced (EPB) shields can be used for soil excavation during box jacking, with different work modes resulting in distinct ground deformation patterns. Additionally, lubrication grouting has been found to effectively reduce friction resistance and affect vertical ground deformation. The study also examines the lessons learned from case studies and proposes optimization measures. This study can serve as a valuable reference for the tunneling industry, providing insights into the pipe-umbrella box jacking method and its application in constructing large rectangular tunnels in soft ground.","PeriodicalId":509035,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":"70 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139852889","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}