Estimate freeway travel time reliability under recurring and nonrecurring congestion

Travel time and its reliability are considered as intuitive measure of service quality by transportation agencies. Moreover, highly reliable travel times allow for arriving at work or other destinations on time in the context of personal travel and facilitate just-in-time logistics services in freight operations. Travel times are the result of the traffic congestion. By considering different impact factors and shortcoming of the sensing technologies, this dissertation proposed methods for travel time and its reliability estimation. First of all, this dissertation presented a method to estimate corridor-level travel times based on data collected from roadside radar sensors, considering spatially correlated traffic conditions. Link-level and corridor-level travel time distributions are estimated using these travel time estimates and compared with the ones estimated based on probe vehicle data. The maximum likelihood estimation is used to estimate the parameters of Weibull, gamma, normal, and lognormal distributions. According to the log likelihood values, lognormal distribution is the best fit among all the tested distributions. Corridor-level travel time reliability measures are extracted from the travel time distributions. The proposed travel time estimation model can well capture the temporal pattern of travel time and its distribution. Second, a travel time reliability measure estimation method is proposed by incorporating standstill distance and time headway distributions in car-following models. The method is based on simplified two-component travel time distribution. By using Monte Carlo simulation, the speed-density region under congested condition and the travel time reliability measures can be generated. The results shows that the speed-density region derived from the steady-state Pipes model encloses most of the field data. Moreover, the proposed method estimate travel time reliability measures more precisely and faster, compared with using VISSIM simulation. Finally, a work zone travel time estimation approach is proposed in this dissertation. First, the impact of work zone on capacity is investigated. For the work zone capacity prediction framework, the predicted upper bound of capacity is close to the maximum 15-min flow rate. Moreover, based on the predicted capacity, density at capacity and free flow speed, work zone travel times are estimated by using the modified segment speed estimation model from the study of Newman. The estimated travel times roughly followed the pattern of the INRIX travel times. Moreover, the travel time reliability indices are estimated directly from the estimated travel times. The result shows that the travel time reliability indices based on estimated travel times are close to the indices based on INRIX travel times

Business Strategies to Improve On-Time Deliveries and Profits in Southcentral Alaska

Traffic congestion can cause late deliveries, decreased profits from vehicle fuel idling in traffic, and delayed distribution in tight delivery windows. The focus of this study was on developing strategies that business leaders could use to increase on-time deliveries. The conceptual frameworks for this case study were systems theory, traffic equilibrium theory, bathtub theory, and kinematic wave theory. Data were collected from semistructured interviews with 6 delivery service leaders from 3 delivery businesses in Southcentral Alaska. In addition, secondary data were collected from government information. Interview responses were coded to identify trends including delivery time, business activity, and amount of roadway congestion. Two major themes emerged from the interviews: time of day affecting when traffic congestion occurred, and limited alternate transportation routes causing congestion in Southcentral Alaska. The findings indicated that the best strategy to help reduce traffic congestion involved instituting toll optimization and high occupant vehicles lanes. The implications for effecting social change include how business leaders can help reduce traffic congestion using toll optimization, and how high occupant vehicle lanes could encourage Southcentral Alaskans to carpool

Modelling Tools and Simulation Platforms for Advanced Driver Assistance Systems

Recent developments in Advanced Driver Assistance Systems (ADAS) lead to the concept of eco-driving support systems, which assist drivers in controlling vehicles in a sustainable way by reducing fuel consumption and carbon dioxide emissions. In this thesis, an algorithm for an ecological Adaptive Cruise Control (ecoACC) system is designated. In order to test the system in MIL (Model in the Loop) and DIL (Driver In the Loop) environments, an important task is the specification of a fuel consumption model. In the first part of the thesis an overview is presented about fuel consumption models and several eco-devices developed by different authors. In the second part of the thesis an experimental campaign (with a sample of 100 drivers) is carried out in order to specify and validate the model. The survey is supported by the DRIVEIN2 (DRIVEr monitoring: technologies, methodologies, and IN-Vehicle Innovative systems) project. As the major data are collected using the OBD-II port of the vehicle, and in particular the data related the instantaneous fuel consumption, a validation of the former data is carried out in collaboration with the CNR (Consiglio Nazionale delle Ricerche – Istituto motori). To carry out a more realistic simulation a vehicle dynamics model was coupled with the ADAS model. The purpose of the implemented vehicle dynamics model is to simulate, in real time, the vehicle’s dynamic behaviour, thanks to continuous integration of the balance equations regulating the longitudinal and lateral vehicle motion. Furthermore, a model able to provide an estimation of real-time fuel consumption of the vehicle is developed: such a model is embedded in the vehicle model discussed in the following, in order to optimize consumption performance during driving task. The implemented system is a next-generation eco-drive system, in the sense that it is able to observe the driver's behaviour and the current fuel consumption, as well as to simulate the fuel consumption in the same traffic conditions and stimuli the driver is subject to, and finally to compare the actual fuel consumption with this of an eco driver. In this way the system gives a reward to the driver if his/her fuel consumption is lower than those of the eco driver, vice versa the system indicates the possibility to improve his/her driving style

The application of chaos theory to forecast urban traffic conditions

PhD ThesisThis thesis explores the application of Chaos Theory to forecast urban traffic conditions. The research takes advantage of a highly resolved temporal and spatial data available from the Split Cycle Optimisation Technique (SCOOT) system, in order to overcome the limitations of previous studies to investigate applying Chaos Theory in traffic management. This thesis reports on the development of a chaos-based algorithm and presents results from its application to a SCOOT controlled region in the city of Leicester, UK. A Phase Space Reconstruction method is used to analyse non-linear data from the SCOOT system, and establishes that a 20 second resolved data is suitable for understanding the dynamics of the traffic system. The research develops the Lyapunov exponent as a chaos-based parameter to forecast link occupancy using a multiple regression model based on the temporal and spatial relationships across the links in the network. The model generates a unique forecast function for each link for every hour of the day. The study demonstrates that Lyapunov exponents can be used to predict the occupancy profile of links in the network to a reasonably high level of accuracy (R-values generally greater than 0.6). Evidence also suggests that the predictions from the Lyapunov exponents (rather than occupancy) make it possible to report on the impending conditions over a wider part of the network so that imminent congested conditions can be foreseen in advance and mitigation measures implemented. Thus, the thesis concludes that incorporating chaos-based algorithms in this way can enable urban traffic control systems to be one-step ahead of traffic congestion, rather than one-step behind. This would improve the management of traffic on a more strategic level rather than purely within smaller network regions thus playing an important role in improving journey times and air quality and making a vital contribution to mitigating climate change

Electromagnetic Waves

This volume is based on the contributions of several authors in electromagnetic waves propagations. Several issues are considered. The contents of most of the chapters are highlighting non classic presentation of wave propagation and interaction with matters. This volume bridges the gap between physics and engineering in these issues. Each chapter keeps the author notation that the reader should be aware of as he reads from chapter to the other

Vehicle and Traffic Safety

The book is devoted to contemporary issues regarding the safety of motor vehicles and road traffic. It presents the achievements of scientists, specialists, and industry representatives in the following selected areas of road transport safety and automotive engineering: active and passive vehicle safety, vehicle dynamics and stability, testing of vehicles (and their assemblies), including electric cars as well as autonomous vehicles. Selected issues from the area of accident analysis and reconstruction are discussed. The impact on road safety of aspects such as traffic control systems, road infrastructure, and human factors is also considered

Proceedings of the 3rd International Conference on Models and Technologies for Intelligent Transportation Systems 2013

Challenges arising from an increasing traffic demand, limited resource availability and growing quality expectations of the customers can only be met successfully, if each transport mode is regarded as an intelligent transportation system itself, but also as part of one intelligent transportation system with “intelligent” intramodal and intermodal interfaces. This topic is well reflected in the Third International Conference on “Models and Technologies for Intelligent Transportation Systems” which took place in Dresden 2013 (previous editions: Rome 2009, Leuven 2011). With its variety of traffic management problems that can be solved using similar methods and technologies, but with application specific models, objective functions and constraints the conference stands for an intensive exchange between theory and practice and the presentation of case studies for all transport modes and gives a discussion forum for control engineers, computer scientists, mathematicians and other researchers and practitioners. The present book comprises fifty short papers accepted for presentation at the Third Edition of the conference. All submissions have undergone intensive reviews by the organisers of the special sessions, the members of the scientific and technical advisory committees and further external experts in the field. Like the conference itself the proceedings are structured in twelve streams: the more model-oriented streams of Road-Bound Public Transport Management, Modelling and Control of Urban Traffic Flow, Railway Traffic Management in four different sessions, Air Traffic Management, Water Traffic and Traffic and Transit Assignment, as well as the technology-oriented streams of Floating Car Data, Localisation Technologies for Intelligent Transportation Systems and Image Processing in Transportation. With this broad range of topics this book will be of interest to a number of groups: ITS experts in research and industry, students of transport and control engineering, operations research and computer science. The case studies will also be of interest for transport operators and members of traffic administration

Network resilience

Many systems on our planet are known to shift abruptly and irreversibly from one state to another when they are forced across a "tipping point," such as mass extinctions in ecological networks, cascading failures in infrastructure systems, and social convention changes in human and animal networks. Such a regime shift demonstrates a system's resilience that characterizes the ability of a system to adjust its activity to retain its basic functionality in the face of internal disturbances or external environmental changes. In the past 50 years, attention was almost exclusively given to low dimensional systems and calibration of their resilience functions and indicators of early warning signals without considerations for the interactions between the components. Only in recent years, taking advantages of the network theory and lavish real data sets, network scientists have directed their interest to the real-world complex networked multidimensional systems and their resilience function and early warning indicators. This report is devoted to a comprehensive review of resilience function and regime shift of complex systems in different domains, such as ecology, biology, social systems and infrastructure. We cover the related research about empirical observations, experimental studies, mathematical modeling, and theoretical analysis. We also discuss some ambiguous definitions, such as robustness, resilience, and stability.Comment: Review chapter

The Politics of Place: Heterogeneous Networks in Three New South Wales Local Government Areas

This thesis is concerned with the role of media in the experience of place in three local government areas. It builds upon recent scholarly work that seeks to rehabilitate the relationship between place and media following earlier claims that media usage could only inhibit a sense of place, or bring about a condition of placelessness. The research is informed by interviews conducted with staff and elected officials from the three local government authorities that serve as the primary examples and case studies. The thesis thus explores the ways in which each of these places is experienced as a complex network of heterogeneous people, objects and connections which interact constantly to produce and reproduce new configurations and imaginaries. The process of negotiation between these is identified as the ‘politics of place’, a process that can occur across various connective media including newspapers, television, books, social network sites, tourism brochures, and blogs. It is argued that each of these media may convey an experience or a construction of place that, in turn, build upon pre-existing histories and conceptions. The methodology pursued is informed by actor-network theory (ANT), which urges the tracing of associations between ontologically distinct actants in any given network. Such traces are examined in pre-existing media such as those described above, but there are also emerging forms of media emerging that are shown to also contribute to an understanding of the construction of place

The Multi-Agent Transport Simulation MATSim

"The MATSim (Multi-Agent Transport Simulation) software project was started around 2006 with the goal of generating traffic and congestion patterns by following individual synthetic travelers through their daily or weekly activity programme. It has since then evolved from a collection of stand-alone C++ programs to an integrated Java-based framework which is publicly hosted, open-source available, automatically regression tested. It is currently used by about 40 groups throughout the world. This book takes stock of the current status. The first part of the book gives an introduction to the most important concepts, with the intention of enabling a potential user to set up and run basic simulations.The second part of the book describes how the basic functionality can be extended, for example by adding schedule-based public transit, electric or autonomous cars, paratransit, or within-day replanning. For each extension, the text provides pointers to the additional documentation and to the code base. It is also discussed how people with appropriate Java programming skills can write their own extensions, and plug them into the MATSim core. The project has started from the basic idea that traffic is a consequence of human behavior, and thus humans and their behavior should be the starting point of all modelling, and with the intuition that when simulations with 100 million particles are possible in computational physics, then behavior-oriented simulations with 10 million travelers should be possible in travel behavior research. The initial implementations thus combined concepts from computational physics and complex adaptive systems with concepts from travel behavior research. The third part of the book looks at theoretical concepts that are able to describe important aspects of the simulation system; for example, under certain conditions the code becomes a Monte Carlo engine sampling from a discrete choice model. Another important aspect is the interpretation of the MATSim score as utility in the microeconomic sense, opening up a connection to benefit cost analysis. Finally, the book collects use cases as they have been undertaken with MATSim. All current users of MATSim were invited to submit their work, and many followed with sometimes crisp and short and sometimes longer contributions, always with pointers to additional references. We hope that the book will become an invitation to explore, to build and to extend agent-based modeling of travel behavior from the stable and well tested core of MATSim documented here.