Communications in Transportation Research最新文献

{"title":"Integrating machine learning and extreme value theory for estimating crash frequency-by-severity via AI-based video analytics","authors":"Fizza Hussain ,&nbsp;Yuefeng Li ,&nbsp;Md Mazharul Haque","doi":"10.1016/j.commtr.2024.100147","DOIUrl":"10.1016/j.commtr.2024.100147","url":null,"abstract":"<div><div>Traffic conflict techniques rely heavily on the proper identification of conflict extremes, which directly affects the prediction performance of extreme value models. Two sampling techniques, namely, block maxima and peak over threshold, form the core of these models. Several studies have demonstrated the inefficacy of extreme value models based on these sampling approaches, as their crash estimates are too imprecise, hindering their widespread practical use. Recently, anomaly detection techniques for sampling conflict extremes have been used, but their application has been limited to estimating crash frequency without considering the crash severity aspect. To address this research gap, this study proposes a hybrid model of machine learning and extreme value theory within a bivariate framework of traffic conflict measures to estimate crash frequency by severity level. In particular, modified time-to-collision (MTTC) and expected post-collision change in velocity (Delta-<em>V</em> or Δ<em>V</em>) have been proposed in the hybrid modeling framework to estimate rear-end crash frequency by severity level. Rear-end conflicts were identified through artificial intelligence-based video analytics for three four-legged signalized intersections in Brisbane, Australia, using four days of data. Non-stationary bivariate hybrid generalized extreme value models with different anomaly detection/sampling techniques (isolation forest and minimum covariance determinant) were developed. The non-stationarity of traffic conflict extremes was handled by parameterizing model parameters, including location, scale, and both location and scale parameters simultaneously. The results indicate that the bivariate hybrid models can estimate severe and non-severe crashes when compared with historical crash records, thereby demonstrating the viability of the proposed approach. A comparative analysis of two anomaly techniques reveals that the isolation forest model marginally outperforms the minimum covariance determinant model. Overall, the modeling framework presented in this study advances conflict-based safety assessment, where the severity dimension can be captured via bivariate hybrid models.</div></div>","PeriodicalId":100292,"journal":{"name":"Communications in Transportation Research","volume":"4 ","pages":"Article 100147"},"PeriodicalIF":12.5,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bridging the gap: Toward a holistic understanding of shared micromobility fleet development dynamics","authors":"Shahnaz N. Fuady ,&nbsp;Paul C. Pfaffenbichler ,&nbsp;Yusak O. Susilo","doi":"10.1016/j.commtr.2024.100149","DOIUrl":"10.1016/j.commtr.2024.100149","url":null,"abstract":"<div><div>Rapid urbanization and shifting demographics worldwide necessitate innovative urban transportation solutions. Shared micromobility systems, such as bicycle- and scooter-sharing programs, have emerged as promising alternatives to traditional urban mobility challenges. This study delves into the complexity of shared micromobility fleet development, focusing on the interplay between fleet size, user demand, regulatory frameworks, economic viability, and public engagement. By employing a system dynamics modeling approach that incorporates causal loop diagrams (CLDs) and stock and flow models (SFMs), we explore various policy scenarios to optimize micromobility management systems. Our findings reveal that financial incentives, such as fee reductions and government subsidies, significantly increase user adoption and profitability, whereas increased operational fees necessitate a delicate balance between cost management and service attractiveness. Sensitivity and uncertainty analyses highlight critical parameters for effective fleet management. This research offers actionable insights for policymakers and operators, promoting sustainable urban transport systems.</div></div>","PeriodicalId":100292,"journal":{"name":"Communications in Transportation Research","volume":"4 ","pages":"Article 100149"},"PeriodicalIF":12.5,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modular flying vehicles: Scheduling modes, social benefits, and challenges","authors":"Di Lv,&nbsp;Yuhao Wang,&nbsp;Liang Wang,&nbsp;Yang Fei,&nbsp;Kai Wang,&nbsp;Xiaobo Qu","doi":"10.1016/j.commtr.2024.100144","DOIUrl":"10.1016/j.commtr.2024.100144","url":null,"abstract":"","PeriodicalId":100292,"journal":{"name":"Communications in Transportation Research","volume":"4 ","pages":"Article 100144"},"PeriodicalIF":12.5,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Harnessing multimodal large language models for traffic knowledge graph generation and decision-making","authors":"Senyun Kuang,&nbsp;Yang Liu,&nbsp;Xin Wang,&nbsp;Xinhua Wu,&nbsp;Yintao Wei","doi":"10.1016/j.commtr.2024.100146","DOIUrl":"10.1016/j.commtr.2024.100146","url":null,"abstract":"","PeriodicalId":100292,"journal":{"name":"Communications in Transportation Research","volume":"4 ","pages":"Article 100146"},"PeriodicalIF":12.5,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Controllability test for nonlinear datatic systems","authors":"Yujie Yang ,&nbsp;Letian Tao ,&nbsp;Likun Wang,&nbsp;Shengbo Eben Li","doi":"10.1016/j.commtr.2024.100143","DOIUrl":"10.1016/j.commtr.2024.100143","url":null,"abstract":"<div><div>Controllability is a fundamental property of control systems, serving as the prerequisite for controller design. While controllability test is well established in modelic (i.e., model-driven) control systems, extending it to datatic (i.e., data-driven) control systems is still a challenging task due to the absence of system models. In this study, we propose a general controllability test method for nonlinear systems with datatic description, where the system behaviors are merely described by data. In this situation, the state transition information of a dynamic system is available only at a limited number of data points, leaving the behaviors beyond these points unknown. Different from traditional exact controllability, we introduce a new concept called <em>ϵ</em>-controllability, which extends the definition from point-to-point form to point-to-region form. Accordingly, our focus shifts to checking whether the system state can be steered to a closed state ball centered on the target state, rather than exactly at that target state. Given a known state transition sample, the Lipschitz continuity assumption restricts the one-step transition of all the points in a state ball to a small neighborhood of the subsequent state. This property is referred to as one-step controllability backpropagation, i.e., if the states within this neighborhood are <em>ϵ</em>-controllable, those within the state ball are also <em>ϵ</em>-controllable. On its basis, we propose a tree search algorithm called maximum expansion of controllable subset (MECS) to identify controllable states in the dataset. Starting with a specific target state, our algorithm can iteratively propagate controllability from a known state ball to a new one. This iterative process gradually enlarges the <em>ϵ</em>-controllable subset by incorporating new controllable balls until all <em>ϵ</em>-controllable states are searched. Besides, a simplified version of MECS is proposed by solving a special shortest path problem, called Floyd expansion with radius fixed (FERF). FERF maintains a fixed radius of all controllable balls based on a mutual controllability assumption of neighboring states. The effectiveness of our method is validated in three datatic control systems whose dynamic behaviors are described by sampled data.</div></div>","PeriodicalId":100292,"journal":{"name":"Communications in Transportation Research","volume":"4 ","pages":"Article 100143"},"PeriodicalIF":12.5,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intelligent vehicle platooning transit","authors":"Chi Xie,&nbsp;Ziyu Zhang,&nbsp;Aijing Su,&nbsp;Bing Wu","doi":"10.1016/j.commtr.2024.100145","DOIUrl":"10.1016/j.commtr.2024.100145","url":null,"abstract":"","PeriodicalId":100292,"journal":{"name":"Communications in Transportation Research","volume":"4 ","pages":"Article 100145"},"PeriodicalIF":12.5,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A multi-functional simulation platform for on-demand ride service operations","authors":"Siyuan Feng ,&nbsp;Taijie Chen ,&nbsp;Yuhao Zhang ,&nbsp;Jintao Ke ,&nbsp;Zhengfei Zheng ,&nbsp;Hai Yang","doi":"10.1016/j.commtr.2024.100141","DOIUrl":"10.1016/j.commtr.2024.100141","url":null,"abstract":"<div><div>On-demand ride services or ride-sourcing services have been experiencing fast development and steadily reshaping the way people travel in the past decade. Various optimization algorithms, including reinforcement learning approaches, have been developed to help ride-sourcing platforms design better operational strategies to achieve higher efficiency. However, due to cost and reliability issues, it is commonly infeasible to validate these models and train/test these optimization algorithms within real-world ride-sourcing platforms. Acting as a proper test bed, a simulation platform for ride-sourcing systems will thus be essential for both researchers and industrial practitioners. While previous studies have established simulators for their tasks, they lack a fair and public platform for comparing the models/algorithms proposed by different researchers. In addition, the existing simulators still face many challenges, ranging from their closeness to real environments of ride-sourcing systems to the completeness of tasks they can implement. To address the challenges, we propose a novel simulation platform for ride-sourcing systems on real transportation networks. It provides a few accessible portals to train and test various optimization algorithms, especially reinforcement learning algorithms, for a variety of tasks, including on-demand matching, idle vehicle repositioning, and dynamic pricing. Evaluated on real-world data-based experiments, the simulator is demonstrated to be an efficient and effective test bed for various tasks related to on-demand ride service operations.</div></div>","PeriodicalId":100292,"journal":{"name":"Communications in Transportation Research","volume":"4 ","pages":"Article 100141"},"PeriodicalIF":12.5,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Traffic expertise meets residual RL: Knowledge-informed model-based residual reinforcement learning for CAV trajectory control","authors":"Zihao Sheng,&nbsp;Zilin Huang,&nbsp;Sikai Chen","doi":"10.1016/j.commtr.2024.100142","DOIUrl":"10.1016/j.commtr.2024.100142","url":null,"abstract":"<div><div>Model-based reinforcement learning (RL) is anticipated to exhibit higher sample efficiency than model-free RL by utilizing a virtual environment model. However, obtaining sufficiently accurate representations of environmental dynamics is challenging because of uncertainties in complex systems and environments. An inaccurate environment model may degrade the sample efficiency and performance of model-based RL. Furthermore, while model-based RL can improve sample efficiency, it often still requires substantial training time to learn from scratch, potentially limiting its advantages over model-free approaches. To address these challenges, this paper introduces a knowledge-informed model-based residual reinforcement learning framework aimed at enhancing learning efficiency by infusing established expert knowledge into the learning process and avoiding the issue of beginning from zero. Our approach integrates traffic expert knowledge into a virtual environment model, employing the intelligent driver model (IDM) for basic dynamics and neural networks for residual dynamics, thus ensuring adaptability to complex scenarios. We propose a novel strategy that combines traditional control methods with residual RL, facilitating efficient learning and policy optimization without the need to learn from scratch. The proposed approach is applied to connected automated vehicle (CAV) trajectory control tasks for the dissipation of stop-and-go waves in mixed traffic flows. The experimental results demonstrate that our proposed approach enables the CAV agent to achieve superior performance in trajectory control compared with the baseline agents in terms of sample efficiency, traffic flow smoothness and traffic mobility.</div></div>","PeriodicalId":100292,"journal":{"name":"Communications in Transportation Research","volume":"4 ","pages":"Article 100142"},"PeriodicalIF":12.5,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Collaborative electric vehicle routing with meet points","authors":"Fangting Zhou ,&nbsp;Ala Arvidsson ,&nbsp;Jiaming Wu ,&nbsp;Balázs Kulcsár","doi":"10.1016/j.commtr.2024.100135","DOIUrl":"10.1016/j.commtr.2024.100135","url":null,"abstract":"<div><div>In this paper, we develop a profit-sharing-based optimal routing mechanism to incentivize horizontal collaboration among urban goods distributors. The core of this mechanism is based on exchanging goods at meet points, which is optimally planned en route. We propose a Collaborative Electric Vehicle Routing Problem with Meet Points (CoEVRPMP) considering constraints such as time windows, opportunity charging, and meet-point synchronization. The proposed CoEVRPMP is formulated as a mixed-integer nonlinear programming model. We present an exact method via branching and a matheuristic that combines adaptive large neighborhood search with linear programming. The viability and scalability of the collaborative method are demonstrated through numerical case studies, including a real-world case and a large-scale experiment with up to 500 customers. The findings underscore the significance of horizontal collaboration among delivery companies in attaining both higher individual profits and lower total costs. Moreover, collaboration helps to reduce the environmental footprint by decreasing travel distance.</div></div>","PeriodicalId":100292,"journal":{"name":"Communications in Transportation Research","volume":"4 ","pages":"Article 100135"},"PeriodicalIF":12.5,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772424724000180/pdfft?md5=483104cc66217184d47dccaf267f5baf&pid=1-s2.0-S2772424724000180-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142312908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the application of blockchain technology in crowdsource autonomous driving map updating","authors":"Benny Wijaya,&nbsp;Mengmeng Yang,&nbsp;Kun Jiang,&nbsp;Wei Zhang,&nbsp;Diange Yang","doi":"10.1016/j.commtr.2024.100140","DOIUrl":"10.1016/j.commtr.2024.100140","url":null,"abstract":"","PeriodicalId":100292,"journal":{"name":"Communications in Transportation Research","volume":"4 ","pages":"Article 100140"},"PeriodicalIF":12.5,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772424724000234/pdfft?md5=19494040fa438c8f34552841ca5654a3&pid=1-s2.0-S2772424724000234-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142232001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}