Ronghui Liu

Ronghui Liu
University of Leeds · Institute for Transport Studies (ITS)

BSc (Peking); PhD (Cambridge)

About

135
Publications
40,327
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3,716
Citations

Publications

Publications (135)
Article
Virtual Coupling (VC) is regarded as a breakthrough to the transitional train operation and control for improving the capability and flexibility in railways. It brings benefits as trains under VC are allowed to operate much closer to one another, forming a virtually coupled train set (VCTS). However, the safe and stable spacing between trains in th...
Article
Energy waste inside the powertrain of electric vehicles (EVs) due to non-optimized acceleration caused by the improper powertrain control variables is not generally considered when designing EVs' optimal driving strategies. To fill this gap, this study designs an optimal EV driving strategy taking a holistic approach by explicitly considering the p...
Article
The rapid expansions of urban rail networks are faced with the growing number of disruptions caused by the complex rail signaling systems, incorrect driving behaviors, and extreme weather. Since urban rail systems are inherently complex and many of these disruptions are usually uncertain and inevitable, the rail managers have gradually paid more at...
Presentation
Full-text available
The slides were published under one of the deliverable outputs of the RAILS project, which have been presented at the 31st European Conference on Operational Research (2021, Athens, Greece). The corresponding deliverable package 1.2 gives a comprehensive survey on the state-of-the-art applications of artificial intelligence in railway sectors. Wher...
Article
The wide-spread application of automatic train operation (ATO) system on metro lines allows short service headways, high-density operations and high operation efficiency. This paper addresses real-time train control for ATO when faced with disturbances or disruptions in its operations. More specifically, the paper focuses on the design of integrate...
Article
Smart card data has emerged in recent years and provide a comprehensive, and cheap source of information for planning and managing public transport systems. This paper presents a multi-stage machine learning framework to predict passengers’ boarding stops using smart card data. The framework addresses the challenges arising from the imbalanced natu...
Technical Report
Full-text available
This report presents a comprehensive review of research projects and state-of-the-art scientific papers of Artificial Intelligence (AI) in railway industry. It represents the output of RAILS Work Package 1 Tasks 1.2 and 1.3. The focus is on European and overseas projects mainly in United States and China. Specific emphasis is devoted to reviewing p...
Chapter
The train virtual coupling system can be considered as an alternative control system introduced for increasing rail line capacity. The separation distance between consecutive trains is theoretically less compared to the other controls. However, the velocity of a following train may fluctuate significantly due to frequent changes of acceleration rat...
Article
Automotive roll-on/roll-off (Ro-Ro) transportation is an efficient and competitive method for the large-scale transshipment of commercial cars. However, the low-efficiency operations and insufficient storage resources of automotive Ro-Ro terminals have constrained the development of Ro-Ro transportation. This paper investigates the storage location...
Article
Full-text available
Carpooling as one of demand management measures is effective in reducing highway congestion. Recent studies have shown that an appropriate spatial allocation of bottleneck capacity between carpool lane and general-purpose lane can lead to peak-spread of the morning commuters' departure time and reduce the system's total trip cost. What is not clear...
Technical Report
Full-text available
This deliverable is the output of RAILS Work Package 1 Task 1.1. As such, it provides a taxonomy of Artificial Intelligence (AI) approaches that are capable of analyzing, predicting and improving railway systems. In this document we make a distinction between different AI perspectives addressing areas such as knowledge representation, reasoning und...
Article
The peak load of a bus route is essential to service frequency determination. From the supply side, there exist ineffective predicted errors of peak load for the optimal number of trips. Whilst many studies were undertaken to model demand prediction and supply optimization separately, little evidence is provided about how the predicted results of p...
Article
Full-text available
Electric vehicles (EVs) endow great potentials for future transportation systems, while efficient charge scheduling strategies are crucial for improving profits and mass adoption of EVs. Two critical and open issues concerning EV charging are how to minimize the total charging cost (Objective 1) and how to minimize the peak load (Objective 2). Alth...
Article
Full-text available
This paper describes the state of advance-ment achieved in the OptiYard research project in the use of optimisation algorithms in interaction with microsimula-tion of the rail-yard and surrounding network towards real-time yard management and communication with the net-work. Two case studies, a hump marshalling yard (mainly Single Wagon Load traffi...
Article
This paper studies a bottleneck model in which the capacity of the bottleneck is constant within a day but changes stochastically from day-to-day between a designed value (good condition) and a degraded one (bad condition). The study relates the travel cost variability due to stochastic capacity with commuters' departure time choice behaviors. We p...
Article
With the development of modern wireless communication technology, especially the vehicle infrastructure integration (VII) technology, vehicles' information such as identification, location, and speed can be readily obtained at upstream cross-section. This information can be used to support traffic signal timing optimization in real time. A dynamic...
Article
Traffic flow models are important tools for traffic management applications such as traffic incident detection and traffic control. In this paper, we propose a novel numerical approximation method for second-order macroscopic traffic flow models. The method is based on the semi-discrete central-upwind numerical flux and high-order reconstructions f...
Preprint
Uncertainty is inevitable in transportation system due to the stochastic change of demand and supply. It is one of the most important factors affecting travelers' choice behavior. Based on the framework of Vickrey's bottleneck model, we designed and conducted laboratory experiment to investigate the effects of stochastic bottleneck capacity on comm...
Article
A motorway weaving section connects a pair of closely spaced entry- and exit-ramps, where intensive lane-changings of merging and diverging vehicles take place over a relatively short space. A detailed trajectory data reveal that a significant proportion of the lane changing at the weaving section exhibits group lane-changing behaviour, in the form...
Article
Full-text available
This paper describes the state of advancement achieved in the OptiYard research project in the use of optimisation algorithms in interaction with microsimulation of the rail-yard and surrounding network towards real-time yard management and communication with the network. Two case studies, a hump marshalling yard (mainly Single Wagon Load traffic)...
Conference Paper
Information on metro passengers’ route choices is important to public transport operators. Recently, smart cards have been introduced in many metropolises, which, however, do not reveal explicitly the actual routes of the cardholders. Research literature shows that a finite mixture model (FMM) may provide an efficient approach to inferring the rout...
Article
Origin-destination flow of passengers in bus networks is a crucial input to the public transport planning and operational decisions. Smart card systems in many cities, however, record only the bus boarding information (namely an open system), which makes it challenging to use smart card data for origin-destination estimations and subsequent analyse...
Article
Dedicated short-range communication (DSRC) technology can provide drivers with information about other vehicles that are beyond the normal range of vision and enables the development of driving support systems such as the rear-end collision warning system (ReCWS). However, technology constraints such as communication delays and GPS error affect the...
Article
We propose a robust optimization model for limited-stop bus service with vehicle overtaking and demand dynamics. Time-dependent stochastic travel time is also considered. The objective is to minimize the total cost (user cost and operation cost) at the planning phase given a target reliability imperative. We further propose a simulation-based optim...
Article
This paper explores the joint effect of economic development, demographic characteristics and the road network on regional road safety. Although extensive efforts have been undertaken to model and predict the safety effects of different influential factors using statistical regression or machine learning models, little evidence is provided on the r...
Article
In railway systems, the train dynamics are usually affected by the external environment (e.g., snow and wind) and wear-out of on-board equipment, leading to the performance degradation of automatic train control algorithms. In most existing studies, the train control models were derived from the mechanical analyzation of train motors and wheel-trac...
Article
This paper proposes a robust dynamic control mechanism for bus transit system, taking account of variations in congestion delays and passenger demand, and combines bus holding and operating speed control strategies. By using a prespecified uncertainty set, we propose a state space model for bus motion with delay disturbances and passenger demand un...
Preprint
Full-text available
With the development of modern wireless communication technology, especially the vehicle infrastructure integration (VII) technology, vehicles' information such as identification, location, and speed can be readily obtained at upstream cross-section. This information can be used to support traffic signal timing optimization in real time. A dynamic...
Article
The advanced train-to-train and train-to-ground communication technologies equipped in high-speed railways have the potential to allow trains to follow each with a steady headway and improve the safety and performance of the railway systems. A key enabler is a train control system that is able to respond to unforeseen disturbances in the system (e....
Article
Full-text available
As the development of traffic detection technology, recent research is directed to a new generation of signal control system supported by new traffic data. One of these directions is dynamic predictive control by incorporating short-term prediction capability. This paper focuses on investigating of dynamic platoon dispersion models which could capt...
Article
Schedule coordination is a proven strategy to improve the connectivity and service quality for bus network, whereas current research mostly optimizes schedule design using the a priori knowledge of users’ routings and ignores the behaviour reactions to coordination status. This study proposes a novel bus stochastic schedule coordination design with...
Article
Full-text available
This paper proposes an alternative flexible transit model with two levels of bus stops, A level and B level. A-level bus stops are fixed, while B-level bus stops are flexible and provide service only when passengers indicate a strong willingness to pay (WTP). This fare structure encourages passengers to choose bus stops with their mobile phones or...
Article
Advances in autonomous and connected vehicles bring new opportunities for intelligent intersection control strategies. In this paper, we propose a centralised way to jointly integrate an intersection control problem with vehicle trajectory planning. It is formulated as a bilevel optimisation problem in which the upper level is designed to minimise...
Article
Full-text available
In the absence of control strategies, headway fluctuation and bus bunching are commonly observed in transit operation due to the stochastic attributes such as travel time and passenger demand. Existing research on real-time control largely focused on developing operational tactics to maintain bus arrival regularity at stops without fully considerin...
Article
The objective of this paper is to provide new insights into commuters’ mode choice behavior in a monocentric closed city with endogenous population distribution, where a congested highway and a crowded railway provide commuting services for residents on a linear urban corridor. We first explore the typical equilibrium mode-choice patterns with exog...
Article
Full-text available
The advancements in communication and sensing technologies can be exploited to assist the drivers in making better decisions. In this paper, we consider the design of a real-time cooperative eco-driving strategy for a group of vehicles with mixed automated vehicles (AVs) and human driven vehicles (HVs). The lead vehicles in the platoon can receive...
Article
Full-text available
Last train timetable design is to coordinate last train services from different lines in an urban rail network for maximizing the number of transfers. It is a challenging operational research problem to balance the competing demand of two decision agents: that of the government agencies to provide the best social services with minimal government su...
Data
Parameter setting for the numerical example. (DOCX)
Article
Full-text available
We consider a container routing problem with stochastic time variables in a sea-rail intermodal transportation system. The problem is formulated as a binary integer chance-constrained programming model including stochastic travel times and stochastic transfer time, with the objective of minimising the expected total cost. Two chance constraints are...
Conference Paper
The existing monocentric city models mostly assume that residents are completely rational when making residential location and mode choice, and their direct utilities only depend on the consumption of two normal goods, a housing service and a composite non-housing good. This paper develops a new model by explicitly integrating the preference for so...
Conference Paper
Full-text available
Numerous models have been developed to estimate route choice from smart card data. However they require route choice set as an input. In this paper we propose a method to determine that automatically. Firstly, we find the K shortest routes. Secondly, we set cut-off criteria to find the reasonable routes, by comparing the in-vehicle, wait and access...
Article
Full-text available
We study urban structure and traffic congestion of a monocentric city by idealizing its suburb and its core as two zones and then exploring what would happen when they are connected by a congestible highway and a crowded railway system. We introduce dynamic congestion effect into commuters’ departure-time and mode choice behaviours, and analyse the...
Article
Full-text available
In this paper, we propose a method to measure the capacity of single-track railway corridors subject to a given degree of balance between the two directional traffic loads and a permitted overall delay level. We introduce the concepts of δ-balance degree and λ-tolerance level to reflect the subjective measures of the railway administrator for capac...
Article
Full-text available
Headway fluctuation and bus bunching are commonly observed in transit operations, while holding control is a proven strategy to reduce bus bunching and improve service reliability. A transit operator would benefit from an accurate forecast of bus propagation in order to effectively control the system. To this end, we propose an ‘ad-hoc’ bus propaga...
Article
Full-text available
This paper focuses on the understanding of the acceleration driving behaviour in motorway weaving sections. An analysis of detailed trajectory data collected from moderately congested traffic flow of a typical weaving section in the M1 motorway, UK (J 42-43). The proposed acceleration model allows the car-following behaviour (acceleration/decelerat...
Article
Full-text available
This paper proposes a novel approach to solve the complex optimal train control problems that so far cannot be perfectly tackled by the existing methods, including the optimal control of a fleet of interacting trains, and the optimal train control involving scheduling. By dividing the track into subsections with constant speed limit and constant gr...
Article
Full-text available
We study urban structure and traffic congestion of a monocentric city by idealizing its suburb and its core as two zones and then exploring what would happen when they are connected by a congestible highway and a crowded railway system. We introduce dynamic congestion effect into commuters’ departure-time and mode choice behaviours, and analyse the...
Conference Paper
Full-text available
We study urban structure and traffic congestion of a monocentric city by idealizing its suburb and its core as two zones and then exploring what would happen when they are connected by a congestible highway and a crowded railway system. We introduce dynamic congestion effect into commuters’ departure-time and mode choice behaviours, and analyse the...
Article
Akamatsu et al. (2006 Akamatsu, T., Sato, S., Nguyen, X.L., 2006. Tradable time-of-day bottleneck permits for morning commuters (in Japanese). JSCE Journal of Infrastructure Planning 62(4), 605–620.[CrossRef] [Google Scholar]) proposed a first-best pricing scheme based on the concept of bottleneck permits. The scheme allows permit holders to pass a...
Article
Full-text available
This paper addresses a route guidance problem for finding the most eco-reliable path in time-variant and stochastic networks such that travelers can arrive at the destination with the maximum on-time probability while meeting vehicle emission standards imposed by government regulators. To characterize the dynamics and randomness of transportation n...
Article
Full-text available
In this paper, we propose a road evolution model by considering the interaction between population distribution and urban road network. In the model, new roads need to be constructed when new zones are built, and existing zones with higher population density have higher probability to connect with new roads. The relative neighborhood graph and a Fe...
Article
Full-text available
Headway fluctuations and " bus bunching " are well known phenomena on many bus routes where an initial delay to one service can disturb the whole schedule due to resulting differences in dwell times of subsequent buses at stops. This paper deals with the influence of a frequent but so far largely neglected characteristic of bus networks on bus bunc...
Article
Full-text available
We propose in this paper an extension of the multi-anticipative optimal velocity car-following model to consider explicitly the desired following distance. The model on the following vehicle’s acceleration is formulated as a linear function of the optimal velocity and the desired distance, with reaction time delay in elements. The linear stability...
Article
Full-text available
We consider a combined train control and scheduling problem involving multiple trains in a railway line with a predetermined departure/arrival sequence of the trains at stations and meeting points along the line. The problem is formulated as a multiphase optimal control problem while incorporating complex train running conditions (including undulat...
Conference Paper
The moving-block system under ERTMS Level 3 represents a continuous detection of train positions, and continuous infrastructure-to-train communication. This allows trains to follow one another in smaller space and time headways than possible in fixed-block systems. Trains form platoons with undisturbed headways and uniform speeds in moving-block sy...
Article
Full-text available
A model of timetable coordination of first trains in urban railway networks, based on the importance of lines and transfer stations, is proposed in this paper. A sub-network connection method is developed, and a mathematical programming solver is utilized to solve the suggested model. A simple test network and a real network of Beijing urban railwa...
Article
Full-text available
This article is focused on determining the Passenger Car Equivalent (PCE) values at different location that divided into road segment and locus. The PCE values are needed to analyse the traffic flows of roads in mixed traffic condition, and differing geometric or environmental conditions. Traffic conditions consist of type and dimension of vehicles...
Article
Full-text available
This paper proposes a road network growing model with the consideration of population distribution and central business district (CBD) attraction. In the model, the relative neighborhood graph (RNG) is introduced as the connection mechanism to capture the characteristics of road network topology. The simulation experiment is set up to illustrate th...
Article
Full-text available
This paper presents idealised natural general and special dynamical models of day-to-day re-routeing and of day to day green-time response. Both green-time response models are based on the responsive control policy P0 introduced in Smith (1979a, b, c 1987). Several results are proved. For example, it is shown that, for any steady feasible demand wi...
Article
Full-text available
This article proposes a tradable credit scheme for managing commuters travel choices. The scheme considers bottleneck congestion and modal split in a competitive highway-transit network with heterogeneous commuters who are distinguished by their valuation of travel time. The scheme charges all auto travelers who pass the bottleneck during a peak-ti...
Conference Paper
Full-text available
Weaving sections are subjected to complex lane-changing movements. In contrary to the other motorway sections where a driver selects a target lane and finds a suitable gap to change lanes, in weaving sections, the drivers’ choices can be significantly affected by the actions of the neighbouring drivers. For instance, if the leader vehicle is changi...
Chapter
Full-text available
Every driver will have experienced the situation in which, as additional traffic joins a road, speeds fall, queues form and travel times become longer and more predictable. Engineers and traffic scientists have devoted considerable effort to understanding how such conditions arise, and how the key parameters of traffic flow, traffic concentration (...