Yibing Wang

• Zhejiang University

Network-wide Traffic State Estimation (TSE), which aims to infer a complete image of network traffic states with sparsely deployed sensors, plays a vital role in intelligent transportation systems. With the development of data-driven methods, traffic dynamics modeling has advanced significantly. However, TSE poses fundamental challenges for data-dr...

The expressway is commonly a system that simultaneously consists of multiple operating scenarios (i.e., normal traffic, accidents, roadworks, etc.). Due to the improvement of traffic efficiency and safety is still the main challenge to road management, capturing the evolution of the traffic status by prediction models in advance is necessary for ri...

Given a partially observed road network, how can we predict the traffic state of unobserved locations? While deep learning approaches show exceptional performance in traffic prediction, most assume sensors at all locations of interest, which is impractical due to financial constraints. Furthermore, these methods typically require costly retraining...

The introduction of connected autonomous vehicles may bring opportunities and challenges to traditional traffic control instruments, like ramp metering. This paper starts by constructing the fundamental diagram for mixed-autonomy traffic based on the car-following behaviors of both connected autonomous vehicles and human-driven vehicles. Then, anal...

This paper proposes a generalized car-following (CF) model to depict the dynamics of traffic flow that includes human-driven vehicles (HDVs), connected vehicles (CVs) and connected and autonomous vehicles (CAVs). Notably, the model integrates human reaction times, information delays, and status data from multiple preceding vehicles endowed with com...

This article proposes a finite-time based sliding-mode controller (FTSMC) and disturbance observer (FTDO) for connected vehicle (CV) platoon with uncertain dynamics. In particular, a recursive structure consisting of first-level and second-level sliding mode surfaces (SMSs) is developed for the chattering of the conventional SMC. Herein, the first-...

Estimated time of arrival (ETA) is an estimate of the vehicle travel time from the origin to destination in the roadworks. From the perspective of travel planning or resource allocation, accurate ETA is significantly important. In recent years, deep learning-based methods represented by recurrent neural networks has been widely used in travel time...

The connected automated vehicles (CAVs) are envisioned to be implemented most likely on electric vehicles, while traditional fuel-powered manually-driven vehicles (MVs) would probably still dominate the automobile market in the next decade. In this context, this paper addresses urban eco-driving of CAVs in mixed traffic and heterogeneous power cond...

This study proposes an optimal control method for connected autonomous vehicles (CAVs) through signalized intersections to reduce the energy consumption of mixed human-driven vehicles (HDVs) and CAV traffic. A real-time optimal control model was developed to optimize the trajectory of each CAV by minimizing energy consumption during the control per...

The connected and automated vehicles (CAVs) technology is envisioned to be implemented most likely on electric vehicles finally, while traditional fuel-powered manually-driven vehicles (MVs) would probably still dominate the automobile market in the next decade. In this context, this paper addressed urban ecological driving (Eco-driving) in traffic...

Capacity drop (CD) at overloaded bottlenecks is a puzzling traffic flow phenomenon with some internal and complicated mechanisms at the microscopic level. Capacity drop is not only important for traffic flow theory and modelling, but also significant for traffic control. A traffic model evaluating traffic control measures needs to be able to reprod...

Macroscopic traffic flow models are of paramount importance to traffic surveillance and control. Before their employments in applications, the models need to be calibrated and validated against real traffic data. The model calibration determines an optimal set of model parameters that minimizes the discrepancy between the modeling results and real...

This article develops a new platoon control strategy for heterogeneous connected vehicles (CVs) subject to time delays and external disturbances. Specifically, based on the third-order vehicle model, a novel platoon controller is developed by embedding the variable time headway (VTH) spacing policy and the nonlinear motion coupling interactions bet...

The dynamic spatiotemporal characteristics of queues at urban intersections are crucial to traffic operation tasks such as signal performance measure and signal optimization. This paper addresses the high time-resolution estimation of queue profile at urban signalized intersection using Extended Kalman Filtering (EKF) with data of connected vehicle...

The highway on-ramp merging area is one of the major sections that form traffic bottlenecks. In a connected vehicle environment, V2V and V2I technologies enable real-time exchange of information, including position, speed, and acceleration. To improve the efficiency of vehicle merging at the on-ramp, this study proposes a cooperative merging contro...

Reliable knowledge of driving states is of great importance to ensure road safety. Anomaly detection in driving behavior means recognizing anomalous driving states as a direct result of either environmental or psychological factors. This paper provides an efficient anomaly recognition approach to identify anomalous lane-changing events in a persona...

Connected and automated vehicles (CAVs) enabled by wireless communication and vehicle automation are believed to revolutionize the form and operation of road transport in the next decades. This paper addresses traffic flow effects of CAVs, and focuses on their lane-changing impacts on the mixed traffic flow of CAVs and human-driven vehicles (HVs)....

This paper addresses real-time joint traffic state and model parameter estimation on freeways using data from fixed sensors and connected vehicles. It investigates how the combined usage of both types of sensing data improves the performance of traffic state estimation (TSE) and what role the online model parameter estimation (OMPE) plays therein....

Currently, with the development of driving technologies, driverless vehicles gradually are becoming more and more available. Therefore, there would be a long period of time during which self-driving vehicles and human-driven vehicles coexist. However, for a mixed platoon, it is hard to control the formation due to the existence of the manual vehicl...

This paper proposes a new car-following (CF) model to capture the realistic behaviors of connected and automated vehicles (CAVs), whose communication topology (CT) among vehicles is characterized by graph theory in the V2V communication environment. By considering the heterogeneous time delays under the fixed and switching CTs, a generalized CF mod...

Three filtering-based approaches to freeway traffic state estimation are studied using measurements from connected vehicles and also a minimum number of fixed detectors. These approaches are: Method 1 based on EKF and the second-order traffic flow model METANET, Methods 2 and 3 based on KF and the conservation equation that is driven by mean sp...

Queue profile is a crucial measure for traffic management in the vicinity of signalized intersections. In this study, we develop a method to identify queue profile using high resolution data, which can be provided from various sources such as drones. Our methodology has three main components which are signal state estimation, queue profile identifi...

Abstract This paper investigates the potential impacts of dynamic wireless power transfer (DWPT) systems on the urban road network with a particular focus on charging and energy consumption implications. The paper is motivated by the recent advancement of connected and autonomous vehicle (CAV) technology and innovations on smart transportation infr...

Taking advantages of connected and autonomous vehicle (CAV) technologies, this paper proposes to optimize the departure times, travel routes, and longitudinal trajectories of CAVs, as well as signal timings at intersections to achieve a stable traffic state, where no vehicles need to stop before entering any intersection and no queue spillover occu...

Vehicular traffic has evolved as a crucial means for the transport of persons and goods, and its importance for the economic and social life of modern society cannot be overemphasized. On the other hand, recurrent vehicular traffic congestion, which appears on a daily basis, particularly in metropolitan areas, around the globe, has been a (increasi...

This paper proposes a longitudinal platoon controller for connected vehicles (CVs) by considering the information of multiple preceding vehicles and the car-following interactions between CVs. The stability of the proposed controller is analyzed using the Routh criterion. For the verification, we develop an integrated platoon control framework for...

Unstable vehicle-to-vehicle (V2V) communication connections are a vital phenomenon in connected vehicle (CV) environments which lead to the change of communication topologies and delays among electric connected vehicles (ECVs). This paper aims to evaluate the effects of the switching period of communication topology and delay on the dynamic perform...

A freeway stretch with even one pair of unmeasured on/off-ramps is not fully observable in traffic states. Flow observability is essential for freeway traffic modeling, surveillance, and control. It is a longstanding and tricky issue to estimate flows for unmeasured ramp pairs. This problem seems to be hardly tractable in conventional approaches, a...

This paper focuses on platoon control of multi-vehicle systems in a realistic vehicle-to-vehicle/vehicle-to-infrastructure (V2V/V2I, or V2X) communication environment. To this end, the communication probability of the beacon transmission is analyzed based on the carrier sense multiple access with collision avoidance (CSMA/CA) mechanism. Then, a new...

Capacity drop at congested freeway bottlenecks is well known with a lot of field observations. This paper studies coordinated ramp metering (RM) and mainstream traffic flow control (MTFC) as well as their integration (RM+MTFC) for freeway traffic, with particular attention to effects of capacity drop on the performance of traffic control measures....

Traffic congestion prediction in citywide road networks is a challenging research field in metropolitan transportation operation and management. Recent advances in GPS technology offer great opportunities to improve upon the limitations on the availability and quality of traffic data. Motivated by the success of deep neural networks and considering...

Although a lot of work has been conducted on car-following modeling, model calibration and validation are still a great challenge, especially in the era of autonomous driving. Most challengingly, besides the immediate benefit incurred with a car-following action, a smart vehicle needs to learn to evaluate the long-term benefits and become foresight...

Freeway congestion may spill back for several kilometers, blocking a number of on/off-ramps upstream. As a consequence, flows at the off-ramps may be substantially reduced, and vehicles bound for the off-ramps are trapped in the mainstream congestion, causing intensified spillback of congestion that blocks even more off-ramps further upstream. Such...

Lane changes are a vital part of vehicle motions on roads, affecting surrounding vehicles locally and traffic flow collectively. In the context of connected and automated vehicles (CAVs), this paper is concerned with the impacts of smart lane changes of CAVs on their own travel performance as well as on the entire traffic flow with the increase of...

Within transportation operations and research, the prediction of traffic congestion for a large-scale road network is always a challenge but is very useful. Different from traditional model driven approaches, this paper demonstrated an innovative data-driven approach that can effectively predict network-wide traffic congestion in short and long-ter...

Innovative technologies and traffic data sources provide great potential to extend advanced strategies and methods in travel behaviour research. Considering the increasing availability of real-time vehicle trajectory data and stimulated by the advances in the modelling and analysis of big data, this paper developed a hybrid unsupervised deep learni...

This paper aims to investigate the characteristics of mixed traffic flow comprising regular and autonomous vehicles. An improved cellular automata model integrated with a multi-agent system was employed as the modeling platform. A 3-lane freeway stretch with one on-ramp and one off-ramp was applied. Two sets of rules for lane changing were designed...

Deterministic/point/vertical and shockwave/physical/horizontal queueing models are widely used in traffic operation to estimate vehicular queue length and delays at bottlenecks such as signalized intersections. The consistency between the two types of queueing model in terms of their estimation performance has been a subject of debate for decades....

This study addresses the problem of trajectory tracking control for connected vehicle (CV) platoon with a focus on the car-following interactions between CVs. In particular, a bidirectional leader-follower topology is exploited to characterize the communication connections among CVs. Then, a dynamic controller for follower vehicles is designed by c...

The technology of autonomous vehicles is expected to revolutionize the operation of road transport systems. The penetration rate of autonomous vehicles will be low at the early stage of their deployment. It is a challenge to explore the effects of autonomous vehicles and their penetration on heterogeneous traffic flow dynamics. This paper aims to i...

Connectivity is a fundamental requirement for vehicular ad hoc networks (VANETs) to secure reliable information dissemination. Connectivity is not guaranteed in the case of traffic sparsity and low market penetration of networked vehicles. Therefore, it is essential to examine the connectivity condition before deploying VANETs. The probabilistic di...

This note comments on the abovementioned paper recently published in IEEE Transactions on Intelligent Transportation Systems. Some important assumptions that were missing in the paper have been found indispensable for the major mathematical conclusions claimed in the paper. This note identifies those assumptions and shows how they were involved in...

Freeway congestion in many cases may spill back for several kilometers, blocking a number of on/off-ramps upstream of the congestion origin. As a result, the total off-ramp flow may substantially reduce, and vehicles bound for the blocked off-ramps are trapped in the mainstream congestion, causing the continuing spillback of congestion that blocks...

he well-known feedback ramp metering algorithm ALINEA can be applied for local ramp metering or included as a key component in a coordinated ramp metering system. ALINEA uses real-time occupancy measurements from the ramp flow merging area that may be at most few hundred meters downstream of the metered on-ramp nose. In many practical cases, howeve...

Zusammenfassung In diesem Aufsatz werden neueste Fortschritte bei der Echtzeitschätzung des Schnellstraßenverkehrs betrachtet. Besonderes Augenmerk wird dabei auf einen allgemeinen Ansatz gerichtet, der sowohl Zustands- als auch Parameterschätzung vereint. Ein weiterer Schwerpunkt ist der Einsatz des Schätzalgorithmus in großräumigen Anwendungen. Z...

The well-known feedback ramp metering algorithm ALINEA can be applied for local ramp metering or used as a key component in a coordinated ramp metering system. ALINEA uses real-time occupancy measurements from the ramp-flow merging area that may be at most few hundred meters downstream of the metered on-ramp nose. In many practical cases, however,...

Urban rail networks play an important role in urban transportation. An unexpected disruption in a rail network can cause a significant degradation in the level of service. When a disruption occurs, it is crucial to provide quick and efficient substitution of services via alternative transportation modes, including bridging disconnected railway stat...

Work zones on motorways necessitate the drop of one or more lanes which may lead to significant reduction of traffic flow capacity and efficiency, traffic flow disruptions, congestion creation, and increased accident risk. Real-time traffic control by use of green–red traffic signals at the motorway mainstream is proposed in order to achieve safer...

Queues of batch arrivals and bulk service including balking and reneging behaviors of customers are commonly observed in real life. This study formulates queues of this type using compound Poisson processes and determines some key probabilistic measures. Analytical investigation is undertaken yielding a range of mathematical results. The developed...

Heavy vehicles are significantly longer and heavier than passenger cars and consequently have quite different acceleration and braking capabilities. Heavy vehicle manoeuvres are therefore likely to influence drivers' vehicle-following behaviour differently to cars. Heavy vehicles can also influence the behaviour of drivers of other vehicles while f...

This research paper explores the importance of turnout location on the provision of bus replacement services that are required during periods of service disruption on a railway network. Turnouts allow trains to be guided from one railway track to another, enabling trains to turn around at a point where services are cancelled. They adjoin railway st...

This study investigates the lane-changing behaviour of drivers of passenger cars and heavy vehicles on freeways and arterial roads. Lane changing has a significant influence on traffic flow through its impact on the surrounding drivers. In this study, detailed vehicle trajectory data are used as a basis for the analysis of drivers' behaviour. It is...

Travel time is a vital performance index in assessing transportation network performance. Vehicle speeds along any network route fluctuate, and route travel times are essentially random. This technical note first examines travel time modeling and estimation with the random modeling of speeds, and then a general approach is presented for travel time...

This paper explores the importance of providing track crossovers in addressing the issue of replacement bus services in response to unplanned rail service disruptions by using a case study in Melbourne, Australia. Crossovers determine the point from which rail replacement bus services can operate and thus are critical in determining the scale, cost...

The behavior of drivers of heavy vehicles when making a decision or executing a lane-changing maneuver on arterial roads and freeways is investigated. Vehicle lane-changing maneuvers often result in instability in traffic flow. The impact on traffic flow of lane changes by heavy vehicles can be even more serious than that of lane changes by passeng...

The 12 papers in this special issue focus on exploiting wireless communication technologies in vehicular traffic networks.

This paper studies a control strategy that is applicable to local ramp metering in the presence of random-location bottlenecks (RLB) downstream of any metered on-ramp. With the support of Vicroads (Highway Department of Victoria State, Australia), local ramp metering in the RLB case has recently been investigated, aiming to design appropriate and p...

This chapter presents the macroscopic simulation tool METANET along with several options, variations, and extensions. METANET simulates complex traffic flow phenomena on motorway networks under all possible traffic conditions (free flow, critical, congested) including the possible presence of incidents. Modeling of the drivers’ routing behavior is...

Real-data testing results of a real-time nonlinear freeway traffic state estimator are presented with a particular focus on its adaptive features. The pursued general approach to the real-time adaptive estimation of complete traffic state in freeway stretches or networks is based on stochastic nonlinear macroscopic traffic flow modeling and extende...

This paper reports on real data testing of a real-time freeway traffic state estimator, with a particular focus on its adaptive capabilities. The pursued general approach to the real-time adaptive estimation of complete traffic state in freeway stretches or networks is based on stochastic macroscopic traffic flow modeling and extended Kalman filter...

Currently, a tremendous amount of human effort and time is spent for maintenance and calibration of operations of Transport Management & Control Systems (TMCSs). TMCS maintenance and calibration is usually performed by experienced personnel in the lack of an automated and systematic approach with no guarantee that the overall maintenance procedure...

This paper addresses a large-scale field test of a real-time freeway network traffic state estimator that was recently developed. The related network traffic flow modeling and state estimator design are first outlined. The test of the estimator for the A3 freeway of 100 km between Naples and Salerno in South Italy is then reported in some detail. T...

In a recent series of articles with largely identical contents and results, some claims are raised about the pertinence and performance of the well-known and widely field-applied local ramp metering algorithm ALINEA and of some extended versions thereof. The expressed claims are based on simulation results with a self-made microscopic simulator. Th...

This special issue contains revised versions of selected papers originally presented at the 9th IEEE International Conference on Intelligent Transportation Systems (ITSC 2006) held in Toronto, Canada, on September 17-20, 2006.

The number of vehicles included in a metered motorway ramp or an urban signalized link at any time is valuable information for real-time control. A Kalman-Filter is employed to produce reliable estimates of this quantity based on real-time measurements of flow and occupancy provided by (at least) three loop detectors. The resulting vehicle-count es...

The available capacity of motorway networks is degraded in presence of traffic congestion, leading to reduced throughput, increased pollution and higher accident risk. The traffic flow efficiency may be increased via suitable application of several control measures, such as ramp metering, driver information, route guidance, variable speed limits an...

This paper reports on real-data testing results for a real-time nonlinear freeway traffic state estimator with particular focus on its adaptive features. The pursued general approach to the real-time adaptive estimation of the complete traffic state in freeway stretches is based on stochastic nonlinear macroscopic traffic flow modeling and extended...