Review
Transportation Science & Technology
Zhaoqi Zang, Xiangdong Xu, Kai Qu, Ruiya Chen, Anthony Chen
Summary: This paper introduces the importance of modeling travel time reliability (TTR) in transportation networks and provides an integrated framework for summarizing the methodological developments and applications of TTR. By adopting a network perspective, a better understanding of TTR characterization, evaluation and valuation, and traffic assignment can be achieved. The paper also discusses some common challenges in TTR modeling and potential directions for future research.
TRANSPORTATION RESEARCH PART C-EMERGING TECHNOLOGIES
(2022)
Article
Computer Science, Artificial Intelligence
Yi Yang, Siyu Huang, Meilin Wen, Xiao Chen, Qingyuan Zhang, Wei Liu
Summary: This study focuses on the reliability measurement method using travel time as a performance index and proposes the travel time belief reliability under uncertain random environment. The model considers the influence of cognitive and random uncertainty on reliability, establishes belief reliability model and route selection algorithm, and discusses the impact of road objective factors and driving state factors on travel time threshold using uncertainty regression analysis method. The feasibility and practicability of the model and algorithm are verified using actual travel tasks in Beijing as an example.
Article
Engineering, Civil
Xiao-Yi Zhou, Neng-Wei Wang, Kang Gao, Sundararajan Natarajan, Wen Xiong, Chao Jiang, Sheng-Yu Qian, C. S. Cai
Summary: This study presents a novel framework for estimating the boundary of mechanical properties of fibre reinforced polymer composites with hybrid and internal uncertainties. The random and interval uncertainties are modeled using Hermite and Chebyshev polynomials, respectively, within a PCE-based surrogate model. The proposed method accurately obtains the upper and lower bounds of structural responses of FRP composite structures.
THIN-WALLED STRUCTURES
(2023)
Article
Management
Ernst Roos, Ruud Brekelmans, Wouter van Eekelen, Dick den Hertog, Johan S. H. van Leeuwaarden
Summary: Chebyshev's inequality provides an upper bound on the tail probability of a random variable based on its mean and variance. This study provides alternative tight lower and upper bounds on the tail probability given a bounded support, mean, and mean absolute deviation of the random variable. These bounds are obtained as exact solutions to semi-infinite linear programs.
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH
(2022)
Article
Engineering, Civil
Zhengchao Zhang, Meng Li
Summary: An increasing number of vehicles cause traffic congestion and long commuting time, making it important to find fast driving paths. However, effective route planning is challenging due to complex variations in traffic conditions. Existing strategies based on either traffic state before departure or short-term prediction have limitations. To address this problem, we propose a route planning approach that combines empirical observations with statistical models of error distributions to create a stochastic and time-varying road network model. Experimental results validate the significant performance improvement of our approach in peak hours.
IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS
(2023)
Article
Mathematics
Yi Yang, Jiaying Gu, Siyu Huang, Meilin Wen, Yong Qin
Summary: This paper proposes a novel uncertain multi-criteria decision-making method for evaluating the reliability of transportation systems. By integrating uncertainty theory into the analytic hierarchy process, the belief reliability of regional travel time is evaluated and compared with other methods.
Article
Chemistry, Multidisciplinary
Yongyi Li, Shiqi Wang, Xiaorui Zhang, Mengxing Lv
Summary: This study focuses on the estimation and reliability research of post-earthquake traffic travel time. By analyzing the relationship among vehicle trajectory, target path, and road network path, the intermediate parameters were defined and improved. The road damage identification method using lane detection was applied to evaluate the damage of roads after the earthquake. Bayesian average adaptive kernel density estimation method was used to estimate the distribution of post-earthquake road travel time, and a new formula for calculating the reliability of road travel time after the earthquake was proposed. The results show that the travel time of the path before the earthquake is the most dependable, and with the increase in the earthquake damage index, the travel time of this road section becomes increasingly unreliable.
APPLIED SCIENCES-BASEL
(2022)
Article
Engineering, Civil
Mo Zhao, Xiaoxiao Zhang, Justice Appiah, Michael D. Fontaine
Summary: This study developed machine learning models to predict travel time reliability, using random forest algorithms and multiple data sources. The results showed that both models accurately predicted travel time reliability, with the GRF model performing better for predicting the 50th percentile travel time and the QRF model achieving slightly better predictions for the 90th percentile. A case study demonstrated the use of these models for estimating the impact of improvement projects on travel time reliability. Both models captured the trend in reliability change, with the GRF model preferred for estimating the level of travel time reliability.
TRANSPORTATION RESEARCH RECORD
(2023)
Article
Engineering, Electrical & Electronic
Karl-Ludwig Besser, Eduard A. Jorswieck
Summary: With future technologies, the amount of sensitive data transmitted wirelessly will increase, raising questions about secure data transmission. Information-theoretic security has gained increasing attention besides cryptography. This study investigates upper and lower bounds on secrecy outage probability for slowly-fading wiretap channels with arbitrary dependency structures, considering cases with and without channel state information at the transmitter and the legitimate receiver.
IEEE TRANSACTIONS ON COMMUNICATIONS
(2021)
Article
Mathematics, Applied
Fiaz Ahmad Bhatti, G. G. Hamedani, Mashail M. Al Sobhi, Mustafa C. Korkmaz
Summary: The BXII-PC distribution is a four-parameter lifetime model with flexible hazard rate, featuring flexible failure rate and density function shapes. Various mathematical properties and six estimation methods have been established, with simulation studies and real data application confirming the model's potential.
Article
Mathematics
Augusta Ratiu, Nicusor Minculete
Summary: In this study, a new expression d lambda(x,y) is introduced on a real normed space X, and its characterization and estimates are obtained. The relation between d(lambda)(x,y) and various types of angular distances in a real normed space is also explored.
Article
Automation & Control Systems
Anne G. Balter, Antoon Pelsser
Summary: This article discusses the importance of recognizing the limitations of models in financial and economic decision-making under uncertainty. The authors propose a set of clear alternative models and derive a quantitative upper limit on the uncertainty set using probability measures. The research also establishes a relationship between the ambiguity bound and numerical values on several divergence measures.
SYSTEMS & CONTROL LETTERS
(2021)
Article
Engineering, Industrial
Jian Deng
Summary: Probabilistic reliability analysis in geotechnical engineering requires accurate determination of probability distributions for soil properties. This paper proposes an unbiased method using the maximum entropy method to estimate probability distributions from fractional moments of observed data. A case study on undrained shear strength of soil in Canada is presented to validate the method.
RELIABILITY ENGINEERING & SYSTEM SAFETY
(2022)
Article
Engineering, Geological
Wenmin Yao, Changdong Li, Changbin Yan, Hongbin Zhan
Summary: The study proposes a hybrid framework for slope reliability based on Bayesian sequential updating technology, integrating prior knowledge, multiple estimation methods, and model uncertainties to estimate slope reliability with limited geotechnical data. Through experiments with three slope examples, the framework is shown to provide reliable and accurate estimations of slope reliability.
Article
Computer Science, Interdisciplinary Applications
Xianping Du, Hongyi Xu, Feng Zhu
Summary: Traditional structural optimal design methods may not achieve global optimum due to uncertainty, prompting the development of a data mining method based on decision tree technique to generate multiple satisfactory design regions and improve design reliability.
COMPUTERS & STRUCTURES
(2021)
Article
Transportation
Mohammad Hossein Chinaei, Taha Hossein Rashidi, Travis Waller
Summary: This paper introduces a distributed architecture for a MaaS digital network using blockchain technology, which integrates multiple service providers to deliver multimodal mobility services. The paper proposes crypto-tickets as a means of service ownership and evaluates the efficacy of the blockchain-based ownership scheme against traditional membership plans. Finally, the potentials of blockchain in personalizing service ownership, congestion management, and data trading between stakeholders of a comprehensive MaaS platform are discussed.
TRANSPORTATION LETTERS-THE INTERNATIONAL JOURNAL OF TRANSPORTATION RESEARCH
(2023)
Article
Transportation
Chi Xie, Jue Hou, Ti Zhang, Travis Waller, Xiqun Chen
Summary: This paper examines the impact of electricity-charging prices on the routing choice and flow pattern of electric vehicles in a home-workplace commute traffic network. It proposes a convex programming model to characterize commuters' charging behavior under different prices and designs a path-based solution algorithm to solve this problem.
TRANSPORTATION LETTERS-THE INTERNATIONAL JOURNAL OF TRANSPORTATION RESEARCH
(2023)
Article
Transportation
Chi Xie, Yanjie Wan, Min Xu, Xiqun Chen, Travis Waller
Summary: This article reinvestigates the mathematical formulations of traffic assignment problems with perception stochasticity and demand elasticity, proposing a pair of dual general formulations. The equilibrium or optimality conditions of these problems can be redefined as a combination of equations, and the solutions of the primal and dual formulations have been proven to be equivalent and unique. Algorithmic analysis and numerical tests suggest that the dual formulation-based algorithm, the Cauchy algorithm, is more suitable for large-scale problems and converges faster than the primal formulation-based Frank-Wolfe algorithm.
TRANSPORTATION LETTERS-THE INTERNATIONAL JOURNAL OF TRANSPORTATION RESEARCH
(2023)
Article
Engineering, Civil
Siroos Shahriari, Edward N. Robson, Jason Wang, Vinayak V. Dixit, S. Travis Waller, Taha H. Rashidi
Summary: Traditional transport models often do not account for broader changes in the economy, so there is a need for an integrated CGE and transport model to quickly assess the economic impacts of transport projects and policies.
Article
Transportation Science & Technology
Zesheng Cheng, Taha Hossein Rashidi, Sisi Jian, Mojtaba Maghrebi, Steven Travis Waller, Vinayak Dixit
Summary: This paper develops an innovative approach to estimating the actual demand at a carsharing station using carsharing records, spatio-temporal correlated variables, and emerging data sources. The paper also provides recommendations related to the operation policies of the service providers based on the analysis results.
TRANSPORTATION RESEARCH PART C-EMERGING TECHNOLOGIES
(2022)
Article
Transportation Science & Technology
Bangyang Wei, Xiang Zhang, Wei Liu, Meead Saberi, S. Travis Waller
Summary: This study investigates the road capacity allocation scheme and step tolling-rewarding scheme for carpooling. The proposed capacity allocation schemes reserve road service capacity during designated time windows for specific carpooling vehicles, and the study models the potential braking or tactical waiting behavior due to temporal changes of right-of-way under the capacity allocation schemes. By integrating the step tolling-rewarding scheme with the capacity allocation scheme, the study manages the carpooling choices and reduces total system cost. Numerical studies are presented to illustrate the analytical results. The findings suggest that carpooling should not be rewarded in some occasions to improve system efficiency.
TRANSPORTATION RESEARCH PART C-EMERGING TECHNOLOGIES
(2022)
Article
Computer Science, Interdisciplinary Applications
Haoning Xi, Yili Tang, S. Travis Waller, Amer Shalaby
Summary: Mobility-as-a-Service (MaaS) is an emerging business model that integrates various travel modes into a single on-demand mobility service. This study proposes a MaaS ecosystem that provides both mobility and instant delivery services by sharing the same multimodal transport system. A bilaterial surcharge-reward scheme (BSRS) is introduced to manage the integrated mobility and delivery demand, and a solution algorithm is developed to optimize the system equilibrium costs.
COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING
(2023)
Article
Transportation Science & Technology
Ali Najmi, Taha H. Rashidi, Travis Waller
Summary: This paper proposes a generalized multi-modal multi-provider market equilibrium model to evaluate the operation of transport systems. The model includes various modes of transportation such as private vehicles, walking, public transport, ride-sourcing, and ridesharing. The economic behaviors of service providers and a network operator are modeled using optimization problems and user equilibrium conditions, forming a complementarity formulation for the market at equilibrium. Extensive computational experiments demonstrate the model's applicability in handling various market responses to technological improvements, demand changes, emissions restrictions, and cultural barriers.
TRANSPORTATION RESEARCH PART C-EMERGING TECHNOLOGIES
(2023)
Article
Economics
Julieta Rottemberg, Milad Ghasri, Hanna Grzybowska, Alfred M. Dockery, S. Travis Waller
Summary: This paper addresses the travel-related decisions of rural and remote populations, aiming to enhance equitable access to basic amenities. Through analyzing attractiveness and travel distance distribution, it reveals the impact of local development on travel patterns in remote communities.
JOURNAL OF TRANSPORT GEOGRAPHY
(2022)
Article
Construction & Building Technology
Zixuan Chen, Ahmed W. A. Hammad, Steven Travis Waller, Assed Naked Haddad
Summary: This paper presents a novel multi-objective mixed integer linear programming model that considers the selection of suitable suppliers, inventory management practices, and order quantities to optimize the trade-off between procurement cost and material delay impacts. The proposed model treats material prices, supplier capacities, and delays as fuzzy scenario-based parameters and is validated through numerical testing. The sensitivity analysis shows the importance of accurate estimation for uncertain parameters. The paper also demonstrates the higher performance of the proposed model compared to deterministic market conditions.
AUTOMATION IN CONSTRUCTION
(2023)
Article
Economics
Haoning Xi, Wei Liu, S. Travis Waller, David A. Hensher, Philip Kilby, David Rey
Summary: In the context of Mobility-as-a-Service (MaaS), the transportation sector is shifting towards user-centric business models that prioritize user experience and customized mobility solutions. This study proposes an auction-based mechanism and optimization models for the demand-side management of MaaS systems. The mechanism allows users to bid for mobility services based on their willingness to pay and experience-related preferences, and the optimization models aim to maximize social welfare by optimally allocating mobility resources in real-time. Extensive simulations using realistic mobility data demonstrate the benefits of the proposed mechanism.
TRANSPORTATION RESEARCH PART B-METHODOLOGICAL
(2023)
Article
Environmental Studies
Bangyang Wei, Bo Du, Meead Saberi, S. Travis Waller, Wei Liu
Summary: This study investigates the strategy of allocating road space as parking for electric ride-sourcing vehicles (ERVs) to reduce cruising. The results show that providing parking increases ride-sourcing demand, reduces charging demand, and increases profit and social welfare.
TRANSPORTATION RESEARCH PART D-TRANSPORT AND ENVIRONMENT
(2023)
Article
Engineering, Civil
S. Travis Waller, Moeid Qurashi, Anna Sotnikova, Lavina Karva, Sai Chand
Summary: This paper examines the impact of the ongoing invasion in Ukraine on traffic behavior using analytics and zonal-based network models. The data-driven approach utilizes obtained travel-time conditions within an evolutionary algorithm framework to infer origin-destination demand values in an automated process. The novelty lies in the analysis to ensure the appropriateness of obtained data, the direct linkage of the analysis to the timeline of disruptions, and the identification of specific network metrics for conceptualizing the impact of conflict disruptions on traffic network conditions.
TRANSPORTATION RESEARCH RECORD
(2023)
Article
Engineering, Civil
Navid Kalantari, Hamid Mirzahossein, Pooyan Najafi, Travis Waller, Xiang Zhang
Summary: Although demand management has been proven to be effective in managing congestion, many organizations still focus on network modification and capacity increase as congestion relief measures. The network design problem plays a significant role in shaping urban transportation networks. This study proposes an efficient solution algorithm for the continuous network design problem and shows that it can solve the problem in a shorter time with high accuracy.
TRANSPORTATION RESEARCH RECORD
(2023)
Review
Transportation
Can Li, Lei Bai, Lina Yao, S. Travis Waller, Wei Liu
Summary: Transportation is crucial for the economy and urban development, but it faces challenges in terms of efficiency, sustainability, resilience, and intelligence. Reinforcement Learning (RL) has emerged as a useful approach for smart transportation applications, allowing autonomous decision-makers to learn from experiences and make optimal actions in complex environments. This paper conducts a bibliometric analysis to understand the development of RL-based methods in transportation applications and provides a comprehensive literature review on the specific topics. Future research directions for RL applications and developments are also discussed.
TRANSPORTMETRICA B-TRANSPORT DYNAMICS
(2023)
Article
Economics
Songyot Kitthamkesorn, Anthony Chen, Seungkyu Ryu, Sathaporn Opasanon
Summary: The study introduces a new mathematical model to determine the optimal location of park-and-ride facilities, addressing the limitations of traditional models and considering factors such as route similarity and user heterogeneity.
TRANSPORTATION RESEARCH PART B-METHODOLOGICAL
(2024)
