{"title":"Timing co-evolutionary path optimisation method for emergency vehicles considering the safe passage","authors":"Jiabin Wu , Yifeng Lin , Weiwei Qi","doi":"10.1080/23249935.2023.2253477","DOIUrl":"10.1080/23249935.2023.2253477","url":null,"abstract":"<div><div>Emergency vehicles encounter traffic accidents at intersections of the network frequently, which seriously threatens the lives of rescue teams and patients. To improve the driving safety and travel efficiency of emergency vehicles, this study proposes a new method of timing co-evolutionary path optimisation for emergency vehicles based on the safety evaluation of intersections in an uncertain environment. First, the associated benefit calculation of emergency priority for vehicles passing through the nodes and road sections is provided then. Second, a mathematical description of the emergency vehicle path optimisation model is proposed, and its primary optimisation objective is to minimise travel time. A secondary optimisation objective based on a flexible time window is proposed to optimise the risk coefficient of the rescue path. Finally, an improved ripple-spreading algorithm is designed to find the optimal path. The findings can help to provide auxiliary decision support for the path selection of emergency rescue actions.</div></div>","PeriodicalId":48871,"journal":{"name":"Transportmetrica A-Transport Science","volume":"21 2","pages":"Pages 1-33"},"PeriodicalIF":3.6,"publicationDate":"2025-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46888455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yilang Hao , Zhibin Chen , Jiangang Jin , Xiaotong Sun
{"title":"Joint operation planning of drivers and trucks for semi-autonomous truck platooning","authors":"Yilang Hao , Zhibin Chen , Jiangang Jin , Xiaotong Sun","doi":"10.1080/23249935.2023.2266041","DOIUrl":"10.1080/23249935.2023.2266041","url":null,"abstract":"<div><div>Semi-autonomous truck platooning, a futuristic and promising traveling mode of trucks on highways, has received extensive attention as autonomous driving gains more maturity. Under the semi-autonomous platooning mode, rather than requiring a human driver for each truck in the platoon, only one human driver is needed for the leading truck, and all following trucks can be controlled by autonomous driving and wireless communication technology. Therefore, in addition to saving energy, such a technology can help reduce labor costs by using fewer drivers to fulfill the same demand. Compared to traditional truck platooning, the schedules of drivers under semi-autonomous truck platooning may not be exactly the same as trucks, which are usually neglected in recent studies. Therefore, in this paper, we make the first attempt to develop a mathematical modeling framework to optimise the operation plan of drivers and trucks interdependently. To be mentioned, the truck fleet is equipped with the semi-autonomous platooning function and time windows. Specifically, the operation plan will dictate the number of drivers to be dispatched, and traveling routes and time schedules of drivers and trucks interdependently with the objective to minimise the total operation cost, including drivers' fixed dispatch cost, on-road labor cost, and energy consumption cost while fulfilling all delivery demands. To tackle the large-scale problem in a timely manner, a tailored Lagrangian Relaxation approach is proposed to solve the model. Numerical experiments are conducted to demonstrate the performance of the proposed modeling framework and validate the feasibility and efficiency of the proposed solution algorithm.</div></div>","PeriodicalId":48871,"journal":{"name":"Transportmetrica A-Transport Science","volume":"21 2","pages":"Pages 1-37"},"PeriodicalIF":3.6,"publicationDate":"2025-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135141513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Safe and efficient manoeuvring for emergency vehicles in autonomous traffic using multi-agent proximal policy optimisation","authors":"Leandro Parada , Eduardo Candela , Luis Marques , Panagiotis Angeloudis","doi":"10.1080/23249935.2023.2246586","DOIUrl":"10.1080/23249935.2023.2246586","url":null,"abstract":"<div><div>Manoeuvring in the presence of emergency vehicles is still a major issue for vehicle autonomy systems. Most studies that address this topic are based on rule-based methods, which cannot cover all possible scenarios that can take place in autonomous traffic. Multi-Agent Proximal Policy Optimisation (MAPPO) has recently emerged as a powerful method for autonomous systems because it allows for training in thousands of different situations. In this study, we present an approach based on MAPPO to guarantee the safe and efficient manoeuvring of autonomous vehicles in the presence of an emergency vehicle. We introduce a risk metric that summarises the potential risk of collision in a single index. The proposed method generates cooperative policies allowing the emergency vehicle to go at $ 15 % $ <span><math><mn>15</mn><mi>%</mi></math></span> higher average speed while maintaining high safety distances. Moreover, we conduct a comprehensive evaluation of our method in a wide range of scenarios, including assessing the trade-offs between traffic efficiency and safety, measuring the scalability of the approach with respect to the number of autonomous vehicles, analysing different distributions of mixed human and autonomous traffic, and examining the various levels of cooperation and competition among agents.</div></div>","PeriodicalId":48871,"journal":{"name":"Transportmetrica A-Transport Science","volume":"21 2","pages":"Pages 1-29"},"PeriodicalIF":3.6,"publicationDate":"2025-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136392616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Bifurcation control based on improved intelligent driver model considering stability and minimum gasoline consumption","authors":"Liyou Li , Weilin Ren , Rongjun Cheng","doi":"10.1080/23249935.2023.2243345","DOIUrl":"10.1080/23249935.2023.2243345","url":null,"abstract":"<div><div>Advanced driver assistance system (ADAS) plays an important role in the transition period before the full maturity of self-driving technology. In this paper, an intelligent driver model with multiple time delays (IDM-MTD) is established to describe the dynamic characteristics of vehicles equipped with ADAS. Moreover, a control term that considers the velocity difference between the current and historical moment is selected for assistance driving. A novel framework is proposed to determine control parameters in controlled IDM-MTD. The definite integral stability method (DISM) is integrated into the framework to constrain the range of parameters that make the system stable. In the control strategy design process, this paper places significant emphasis on the implementation of the DISM modification to effectively address redundant iteration steps by exploiting the characteristic of bifurcation. Through numerical simulation, a two-dimensional optimal parameter combination is found, which not only stabilizes traffic flow but also produces minimal gasoline consumption.</div></div>","PeriodicalId":48871,"journal":{"name":"Transportmetrica A-Transport Science","volume":"21 2","pages":"Pages 1-22"},"PeriodicalIF":3.6,"publicationDate":"2025-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44620378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A multiclass simulation-based dynamic traffic assignment model for mixed traffic flow of connected and autonomous vehicles and human-driven vehicles","authors":"Behzad Bamdad Mehrabani , Jakob Erdmann , Luca Sgambi , Seyedehsan Seyedabrishami , Maaike Snelder","doi":"10.1080/23249935.2023.2257805","DOIUrl":"10.1080/23249935.2023.2257805","url":null,"abstract":"<div><div>Connected and Autonomous Vehicles (CAVs) may exhibit different driving and route choice behaviours compared to Human-Driven Vehicles (HDVs), which can result in a mixed traffic flow with multiple classes of route choice behaviour. Therefore, it is necessary to solve the Multiclass Traffic Assignment Problem (TAP) for mixed traffic flow. However, most existing studies have relied on analytical solutions. Furthermore, simulation-based methods have not fully considered all of CAVs’ potential capabilities. This study presents an open-source solution framework for the multiclass simulation-based TAP in mixed traffic of CAVs and HDVs. The proposed model assumes that CAVs follow system optimal with rerouting capabilities, while HDVs follow user equilibrium. It also considers the impact of CAVs on road capacity at both micro and meso scales. The proposed model is demonstrated through three case studies. This study provides a valuable tool that can consider several assumptions for better understanding the impact of CAVs on mixed traffic flow.</div></div>","PeriodicalId":48871,"journal":{"name":"Transportmetrica A-Transport Science","volume":"21 2","pages":"Pages 1-32"},"PeriodicalIF":3.6,"publicationDate":"2025-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134910622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yu Rao , Xiaoyun Feng , Qingyuan Wang , Pengfei Sun
{"title":"The optimal solution to the energy-efficient train control in a multi-trains system-part 1: the algorithm design","authors":"Yu Rao , Xiaoyun Feng , Qingyuan Wang , Pengfei Sun","doi":"10.1080/23249935.2023.2267685","DOIUrl":"10.1080/23249935.2023.2267685","url":null,"abstract":"<div><div>When a train travels in a multi-trains system, the power flow of other trains and the track grades make up the spatial–temporal area (STA) for the train. Finding the optimal solution for the energy-efficient train control problem in STA can help reduce the net energy consumption. This paper studies the analytic method to obtain the optimal solution. In Part 1, we propose an algorithm specifically designed for this problem. The underlying structure of the algorithm is the connection between three optimal states through the optimal feasible strategy. We propose an algebraic method to calculate the optimal feasible strategy and discuss how it intersects with the speed limit. In Part 2, we will discuss the optimality and uniqueness of the optimal feasible strategy. Case studies using data from a real freight railway line are given to demonstrate the effectiveness of the proposed algorithm.</div></div>","PeriodicalId":48871,"journal":{"name":"Transportmetrica A-Transport Science","volume":"21 2","pages":"Pages 1-29"},"PeriodicalIF":3.6,"publicationDate":"2025-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135883168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Convexity and global optimisation of lane-based fixed-time signal model for delay minimisation at an isolated intersection","authors":"Haiming Hao , Hui Jin","doi":"10.1080/23249935.2023.2259014","DOIUrl":"10.1080/23249935.2023.2259014","url":null,"abstract":"<div><div>Lane-based fixed-time signal is basic to various signal control strategies. It performs well in maximizing road capacity, but is faced with significant challenge in minimizing traffic delay. This study validates the convexity of lane-based fixed-time signal model for delay minimization, when lane markings are determined as well as flow factors. Thus Breadth first search algorithm is developed to enumerate the feasible lane markings, which are then screened with flow factors. Cutting plane algorithm is applied to the CMINLP for each feasible lane markings, where the non-linear delay function is converted to a series of linear ones, until the relaxed delay converges to the actual delay. Branch pruning strategy is established for efficiency, to eliminate the lane markings with uncompetitive delay. Numerical analyses follow to validate the proposed algorithm. This research promotes the redesign of lane-based fixed-time signal control.</div></div>","PeriodicalId":48871,"journal":{"name":"Transportmetrica A-Transport Science","volume":"21 2","pages":"Pages 1-23"},"PeriodicalIF":3.6,"publicationDate":"2025-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136341945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Mapping the spatial organisation of air transport network by WENA-MLST analysis","authors":"Chengliang Liu , Bangjuan Wang , Hong Zhang","doi":"10.1080/23249935.2023.2261044","DOIUrl":"10.1080/23249935.2023.2261044","url":null,"abstract":"<div><div>Due to the airline hubs’ organisation such as linkage, hierarchical structure, and hub-and-spoke remains a mystery at a global scale. Thereby, the research aims to unravel the spatial organisation of airline hubs in the air transport network (ATN) by using weighted ego network analysis (WENA), Ht-index, and maximum leaf spanning tree (MLST) at multi-scales. The findings provide valuable insights into the status of different regional cities in the ATN and the critical relationship between hubs and their associated spokes. The result shows that the ATN is a legibly hierarchical network, and three types of airline hubs, i.e. global, international, and regional hubs have been identified. Additionally, the study reveals that the ATN is made up of several regional hub-and-spoke systems, where hubs dominate their subgraphs, with range and geographical proximity effects are observed. Finally, the role of airline hubs as international gateways and domestic hubs is also noted.</div></div>","PeriodicalId":48871,"journal":{"name":"Transportmetrica A-Transport Science","volume":"21 2","pages":"Pages 1-26"},"PeriodicalIF":3.6,"publicationDate":"2025-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136060128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhao Zhang , Yun Yuan , Mingchen Li , Pan Lu , Xianfeng Terry Yang
{"title":"Empirical study of the effects of physics-guided machine learning on freeway traffic flow modelling: model comparisons using field data","authors":"Zhao Zhang , Yun Yuan , Mingchen Li , Pan Lu , Xianfeng Terry Yang","doi":"10.1080/23249935.2023.2264949","DOIUrl":"10.1080/23249935.2023.2264949","url":null,"abstract":"<div><div>Recent studies have shown the successful implementation of classical model-based approaches (e.g. macroscopic traffic flow modelling) and data-driven approaches (e.g. machine learning – ML) to model freeway traffic patterns, while both have their limitations. Even though model-based approaches could depict real-world traffic dynamics, they could potentially lead to inaccurate estimations due to traffic fluctuations and uncertainties. In data-driven models, the acquisition of sufficient high-quality data is required to ensure the model performance. However, many transportation applications often suffer from data shortage and noises. To overcome those limitations, this study aims to introduce and evaluate a new model, named as physics-guided machine learning (PGML), that integrates the classical traffic flow model (TFM) with the machine learning technique. This PGML model leverages the output of a traffic flow model along with observational features to generate estimations using a neural network framework. More specifically, it applies physics-guided loss functions in the learning objective of neural networks to ensure that the model not only consists with the training set but also shows lower errors on the known physics of the unlabelled set. To illustrate the effectiveness of the PGML, this study implements empirical studies with a real-world dataset collected from a stretch of I-15 freeway in Utah. Experimental study results show that the proposed PGML model could outperform the other compatible methods, including calibrated traffic flow models, pure machine learning methods, and physics unguided machine learning (PUML).</div></div>","PeriodicalId":48871,"journal":{"name":"Transportmetrica A-Transport Science","volume":"21 2","pages":"Pages 1-28"},"PeriodicalIF":3.6,"publicationDate":"2025-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135569703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Coordinated flow model for strategic planning of autonomous mobility-on-demand systems","authors":"Jiangbo (Gabe) Yu , Michael F. Hyland","doi":"10.1080/23249935.2023.2253474","DOIUrl":"10.1080/23249935.2023.2253474","url":null,"abstract":"<div><div>High-quality strategic planning of autonomous mobility-on-demand (AMOD) systems is critical for the success of the subsequent phases of AMOD system implementation. To assist in strategic AMOD planning, we propose a dynamic and flexible flow-based model of an AMOD system. The proposed model is computationally fast while capturing the state transitions of two coordinated flows (i.e. co-flows): the AMOD service fleet vehicles and AMOD customers. Capturing important quantity dynamics and conservations through a system of ordinary differential equations, the model can economically respond to a large number and a wide range of scenario-testing requests. The paper illustrates the model efficacy through a basic example and a more realistic case study. The case study envisions replacing Manhattan's existing taxi service with a hypothetical AMOD system. The results show that even a simple co-flow model can robustly predict the systemwide AMOD dynamics and support the strategic planning of AMOD systems.</div></div>","PeriodicalId":48871,"journal":{"name":"Transportmetrica A-Transport Science","volume":"21 2","pages":"Pages 1-39"},"PeriodicalIF":3.6,"publicationDate":"2025-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42002401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}