This paper presents a theoretical development of adaptive cruise control models and platoon operation logic for Automated Highway Systems in the Advanced Vehicle Control Systems (AVeS). Three control modes, constant speed, emergency and vehicle-following, are defined based on the minimum safe stopping distance, and applied to the platoon operations. Desired acceleration model is built for the different cruise control mode by considering the relative velocity, the difference between the relative distance and desired spacing, and the acceleration of the preceding vehicle. A control system model is proposed based on the analysis of vehicle dynamics. The contribution of uncontrolled forces from the air, slop and friction to the vehicle acceleration is considered. Application of control models for two successive vehicles is simulated under the situations of speed transition and emergency stopping. Proper control parameters are determined for different operation mode subject to the conditions: collision avoidance and stability. Same criteria are utilized to the platoon simulation in which the operation logic is regulated so that the platoon leader is operated under either emergency mode or constant speed mode depending upon the . distance from the downstream vehicle, while the intraplatoon vehicles are forced to operate under vehicle-following mode. Three cases under speed transition, emergency stopping and platoon leader splitting are simulated to determine the stable control parameters. Lane capacity analysis shows the tradeoff between safety and efficiency for platoon. modal operations on freeway with guideline or automated highway. / Master of Science

Cities worldwide are faced with the challenge of improving transit service in urban areas using lower cost means. Transit signal priority is considered to be one of the most effective ways to improve the service of transit vehicles. Transit signal priority has become a very popular topic in transportation in the past 20 to 30 years and it has been implemented in many places around the world. In this thesis, transit signal priority strategies are categorized and an extensive literature review on past research on transit signal priority is conducted. Then a case study on Columbia Pike in Arlington (including 21 signalized intersections) is conducted to assess the impacts of integrating transit signal priority and SCOOT adaptive signal control. At the end of this thesis, an isolated intersection is designed to analyze the sensitivity of major parameters on performance of the network and transit vehicles. The results of this study indicate that the prioritized vehicles usually benefit from any priority scheme considered. During the peak period, the simulations clearly indicate that these benefits are typically obtained at the expense of the general traffic. While buses experience reductions in delay, stops, fuel consumption, and emissions, the opposite typically occurs for the general traffic. Furthermore, since usually there are significantly more cars than buses, the negative impacts experienced by the general traffic during this period outweigh in most cases the benefits to the transit vehicles, thus yielding overall negative impacts for the various priority schemes considered. For the off-peak period, there are no apparent negative impacts, as there is more spare capacity to accommodate approaching transit vehicles at signalized intersections without significantly disrupting traffic operations. It is also shown in this study that it is generally difficult to improve the system-wide performance by using transit priority when the signal is already optimized according to generally accepted traffic flow criteria. In this study it is also observed that the system-wide performance decreases rapidly when transit dwell time gets longer. / Master of Science

The problem of this study is to determine the efficiency of the transportation systems of eight Class B schools of Wise County, Texas.

Connected and Automated Vehicles (CAVs) have the potential to revolutionize transportation efficiency and safety through collaborative behavior. This dissertation explores the challenges and opportunities associated with achieving socially optimal cooperative maneuvers, using the problem of cooperative lane-changing to showcase the significance of cooperativeness. Cooperative lane-changing serves as an ideal testbed for examining decentralized optimal control, interactions with uncooperative vehicles, accommodating diverse human driving preferences, and integrating planning and execution processes. Initially, the research focuses on scenarios where all vehicles are cooperative CAVs, leveraging their communication and coordination capabilities. Decentralized optimal control problems are formulated to minimize energy consumption, travel time, and traffic disruption during sequential cooperative lane changes, balancing individual vehicle objectives with system-level goals. The dissertation then extends the analysis to mixed-traffic scenarios involving uncooperative human-driven vehicles (HDVs). A novel approach is developed to ensure safety assurance, combining optimal control with Control Barrier Functions (CBFs) and fixed-time convergence (FxT-OCBF). Robust methods for handling disturbances from uncooperative vehicles are introduced, enhancing the resilience and dependability of cooperative lane-changing maneuvers. An innovative online learning framework is presented to address the complexities of CAVs interacting with HDVs exhibiting diverse driving preferences. Safety preferences are characterized using parameterized CBFs, and an extended Kalman filter dynamically adjusts control parameters based on observed interactions, enabling real-time adaptation to evolving human behaviors. The proposed methodologies bridge the gap between high-level planning and low-level control execution, facilitating safe and near-optimal cooperative maneuvers. Comprehensive analysis demonstrates improved traffic throughput, reduced energy consumption, and enhanced safety compared to non-cooperative or reactive approaches. This research lays the foundation for deploying CAV technologies that prioritize social optimality while addressing uncertainties in mixed-traffic settings, ultimately paving the way for safer and more efficient transportation systems. / 2025-03-11T00:00:00Z

Intelligent Transportation Systems are advanced technologies used to reduce traffic and increase road safety for vulnerable road users. Real-time traffic monitoring is an important technology for collecting and reporting the information required to achieve these goals through the detection and tracking of road users inside an intersection. To be effective, these systems must be robust to all environmental conditions. This thesis explores the fusion of camera and Light Detection and Ranging (LiDAR) sensors to create an accurate and real-time traffic monitoring system. Sensor fusion leverages complimentary characteristics of the sensors to increase system performance in low- light and inclement weather conditions. To achieve this, three primary components are developed: a 3D LiDAR detection pipeline, a camera detection pipeline, and a decision-level sensor fusion module. The proposed pipeline is lightweight, running at 46 Hz on modest computer hardware, and accurate, scoring 3% higher than the camera-only pipeline based on the Higher Order Tracking Accuracy metric. The camera-LiDAR fusion system is built on the ROS 2 framework, which provides a well-defined and modular interface for developing and evaluated new detection and tracking algorithms. Overall, the fusion of camera and LiDAR sensors will enable future traffic monitoring systems to provide cities with real-time information critical for increasing safety and convenience for all road-users. / Thesis / Master of Applied Science (MASc) / Accurate traffic monitoring systems are needed to improve the safety of road users. These systems allow the intersection to “see” vehicles and pedestrians, providing near instant information to assist future autonomous vehicles, and provide data to city planers and officials to enable reductions in traffic, emissions, and travel times. This thesis aims to design, build, and test a traffic monitoring system that uses a camera and 3D laser-scanner to find and track road users in an intersection. By combining a camera and 3D laser scanner, this system aims to perform better than either sensor alone. Furthermore, this thesis will collect test data to prove it is accurate and able to see vehicles and pedestrians during the day and night, and test if runs fast enough for “live” use.

No description available.

Highway Capacity Manual (HCM) 2010 methodology for freeway operations contain procedures for calculating traffic performance measures both for undersaturated and oversaturated flow conditions. However, one of the limitations regarding oversaturated freeway weaving segments is that the HCM procedures have not been extensively calibrated based on field observations on U.S. freeways. This study validates the HCM2010 methodology for oversaturated freeway weaving segment by comparing space mean speed and density obtained from HCM procedure to those generated by a microsimulation model. A VISSIM model is extensively calibrated and validated based on NGSIM field data for the US 101 Highway. Abundance of the NGSIM data is utilized to calibrate and validate the VISSIM model. Results show that HCM methodology has significant limitations and while in some cases it can reproduce density correctly, the study finds that speeds estimated by the HCM methodology significantly differ from those observed in the field. / by Dusan Jolovic. / Thesis (M.S.C.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2012. Mode of access: World Wide Web.

Abstract : Embedded intelligence in vehicular applications is becoming of great interest since the last two decades. Position estimation has been one of the most crucial pieces of information for Intelligent Transportation Systems (ITS). Real time, accurate and reliable localization of vehicles has become particularly important for the automotive industry. The significant growth of sensing, communication and computing capabilities over the recent years has opened new fields of applications, such as ADAS (Advanced driver assistance systems) and active safety systems, and has brought the ability of exchanging information between vehicles. Most of these applications can benefit from more accurate and reliable localization. With the recent emergence of multi-vehicular wireless communication capabilities, cooperative architectures have become an attractive alternative to solving the localization problem. The main goal of cooperative localization is to exploit different sources of information coming from different vehicles within a short range area, in order to enhance positioning system efficiency, while keeping the cost to a reasonable level. In this Thesis, we aim to propose new and effective methods to improve vehicle localization performance by using cooperative approaches. In order to reach this goal, three new methods for cooperative vehicle localization have been proposed and the performance of these methods has been analyzed. Our first proposed cooperative method is a Cooperative Map Matching (CMM) method which aims to estimate and compensate the common error component of the GPS positioning by using cooperative approach and exploiting the communication capability of the vehicles. Then we propose the concept of Dynamic base station DGPS (DDGPS) and use it to generate GPS pseudorange corrections and broadcast them for other vehicles. Finally we introduce a cooperative method for improving the GPS positioning by incorporating the GPS measured position of the vehicles and inter-vehicle distances. This method is a decentralized cooperative positioning method based on Bayesian approach. The detailed derivation of the equations and the simulation results of each algorithm are described in the designated chapters. In addition to it, the sensitivity of the methods to different parameters is also studied and discussed. Finally in order to validate the results of the simulations, experimental validation of the CMM method based on the experimental data captured by the test vehicles is performed and studied. The simulation and experimental results show that using cooperative approaches can significantly increase the performance of the positioning methods while keeping the cost to a reasonable amount. / Résumé : L’intelligence embarquée dans les applications véhiculaires devient un grand intérêt depuis les deux dernières décennies. L’estimation de position a été l'une des parties les plus cruciales concernant les systèmes de transport intelligents (STI). La localisation précise et fiable en temps réel des véhicules est devenue particulièrement importante pour l'industrie automobile. Les améliorations technologiques significatives en matière de capteurs, de communication et de calcul embarqué au cours des dernières années ont ouvert de nouveaux champs d'applications, tels que les systèmes de sécurité active ou les ADAS, et a aussi apporté la possibilité d'échanger des informations entre les véhicules. Une localisation plus précise et fiable serait un bénéfice pour ces applications. Avec l'émergence récente des capacités de communication sans fil multi-véhicules, les architectures coopératives sont devenues une alternative intéressante pour résoudre le problème de localisation. L'objectif principal de la localisation coopérative est d'exploiter différentes sources d'information provenant de différents véhicules dans une zone de courte portée, afin d'améliorer l'efficacité du système de positionnement, tout en gardant le coût à un niveau raisonnable. Dans cette thèse, nous nous efforçons de proposer des méthodes nouvelles et efficaces pour améliorer les performances de localisation du véhicule en utilisant des approches coopératives. Afin d'atteindre cet objectif, trois nouvelles méthodes de localisation coopérative du véhicule ont été proposées et la performance de ces méthodes a été analysée. Notre première méthode coopérative est une méthode de correspondance cartographique coopérative (CMM, Cooperative Map Matching) qui vise à estimer et à compenser la composante d'erreur commune du positionnement GPS en utilisant une approche coopérative et en exploitant les capacités de communication des véhicules. Ensuite, nous proposons le concept de station de base Dynamique DGPS (DDGPS) et l'utilisons pour générer des corrections de pseudo-distance GPS et les diffuser aux autres véhicules. Enfin, nous présentons une méthode coopérative pour améliorer le positionnement GPS en utilisant à la fois les positions GPS des véhicules et les distances inter-véhiculaires mesurées. Ceci est une méthode de positionnement coopératif décentralisé basé sur une approche bayésienne. La description détaillée des équations et les résultats de simulation de chaque algorithme sont décrits dans les chapitres désignés. En plus de cela, la sensibilité des méthodes aux différents paramètres est également étudiée et discutée. Enfin, les résultats de simulations concernant la méthode CMM ont pu être validés à l’aide de données expérimentales enregistrées par des véhicules d'essai. La simulation et les résultats expérimentaux montrent que l'utilisation des approches coopératives peut augmenter de manière significative la performance des méthodes de positionnement tout en gardant le coût à un montant raisonnable.

Recent years have shown a growing concern over increasing traffic volume worldwide. The insufficient road capacity and the resulting congestions have become major problems in many urban areas. Congestions negatively impact the economy, the environment and the health of the population as well as the drivers satisfaction. Current solutions to this topical and timely problem rely on the exploitation of Intelligent Transportation Systems (ITS) technologies. ITS urban traffic management involves the collection and processing of a large amount of geographically distributed information to control distributed infrastructure and individual vehicles. The distributed nature of the problem prompted the development of a novel, scalable ITS-Cloud platform. The ITS-Cloud organises the processing and manages distributed data sources to provide traffic management methods with more accurate information about the state of the traffic. A new approach to service allocation, derived from the existing cloud and grid computing approaches, was created to address the unique needs of ITS traffic management. The ITS-Cloud hosts the collection of software services that form the Cloud based Traffic Management System (CTMS). CTMS combines intersection control algorithms with intersection approach advices to the vehicles and dynamic routing. The CTMS contains a novel Two-Step traffic management method that relies on the ITS-Cloud to deliver a detailed traffic simulation image and integrates an adaptive intersection control algorithm with a microscopic prediction mechanism. It is the first method able to perform simultaneous adaptive intersection control and intersection approach optimization. The Two-Step method builds on a novel pressure based adaptive intersection control algorithm as well as two new traffic prediction schemes. The developed traffic management system was evaluated using a new microscopic traffic simulation tool tightly integrated with the ITS-Cloud. The novel traffic management approaches were shown to outperform benchmark methods for a realistic range of traffic conditions and road network configurations. Unique to the work was the investigation of interactions between ITS components.

Thesis (MScEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The importance of transport should not be underestimated. Transport progresses a person’s quality of life: it connects people to one another and provides access to work, services and recreational opportunities. However, post-apartheid South Africa is unfortunately still faced with a legacy of segregation. While the less-privileged, who mostly live at the fringe of Central Business Districts (CBDs), are captive users of public transport, the private vehicle trend, under the privileged, is becoming more evident. This research project thus proposes that a balanced and integrated sustainable transport system be promoted. That is, one that will aid South Africa in growing and improving its general socio-economical status by providing all its citizens with (equal) access to a balanced transport network. It is believed that, if a multimodal system is promoted, the deficiencies of the current heterogeneous non-integrated systems may be overcome. Therefore, if South Africa’s transport network is augmented with a multimodal platform, the nation will be able to move its citizens effectively and efficiently, without jeopardising the economy, social matters and the environment, today and in the future. Moreover, South Africa will also have the necessary stimulus to utilise the already available resources at its disposal by working together as ‘one’. This research project thus stipulates a (generic) sequential approach needed in achieving an integrated (sustainable) public transport system. The goal of this research project is to create awareness of the benefits that may arise from, and the implementation steps required in obtaining, such a multimodal platform. The focus area for researching the proposition made herein is the City of Cape Town’s (CoCT’s) land transport networks. The City has a management facility, with resultant transport data repository, known as the Transport Management Centre (TMC). This TMC is regarded as one of the finest state of the art facilities in the world and the features thereof offer a sufficient base and point of departure for the promotion of a multimodal transport system. By conducting research in this field, the following portraying aspects, needed for the realisation of the proposition made herein, were found. Firstly, in order to obtain an integrated sustainable transport system, the appropriate Intelligent Transport Systems (ITS) need to be integrated. It is believed that, if an intelligent transport scheme, grounded on ITS applications, is advocated, the City will be in the position to more effectively monitor what is going on, to more accurately predict what might happen in the future, and to manage its transport system proactively on an area-wide basis. Secondly, in order to meet the integration requirements imposed by multimodal transport, a centralised database needs to be created. With such a database in place, information sharing across all modes of private- and public land transport, and thus also between the investors or the operators, will be possible. An example of such a database was developed in Microsoft Access and the modes considered therein are: MyCiti, Metrorail and Golden Arrow Bus Service (GABS). The data stored in this database is historic, but the incorporation of real time information was also catered for. Thirdly, it is believed that the success of the City’s transport system, and the development of a multimodal system, is dependent on the provision of an efficient Advanced Traveller Information System (ATIS). The idea is to promote multimodal transport as a convenient transit option by providing travellers with information on journey planning that aims to counteract their reluctance to change. In order to develop such a multimodal Journey Planner (JP), the unimodal networks considered herein were combined into a supernetwork on which Dijkstra’s Shortest Path Algorithm was applied. This algorithm was programmed in Microsoft Excel’s Visual Basic for Applications (VBA) and it incorporates the following user criteria: the origin, the destination, the user’s mode preference, and the user’s optimisation preference of either time or distance. In conclusion, it can be argued that, with information becoming such a vital commodity in everyday life, the catering for informed travellers are the key to successful future transport services. If travellers are informed about the transport networks’ performance, a positive attitude is fostered. Moreover, by providing travellers with information on journey planning, their feelings of uncertainty and fear of the unknown, that are present in (especially) public transport services, may be neutralised. This information will give the public carte blanche to make decisions that give them the perception of having more ‘control over their lives’. Therefore, if a multimodal JP that can be accessed from one portal is created, people’s inclination to acquire more information will be met. And as a result, traversing in an integrated manner may become the norm. / AFRIKAANSE OPSOMMING: Die belangrikheid van vervoer mag nie onderskat word nie. Vervoer speel ’n belangrike rol in die bevordering van ’n persoon se lewenskwaliteit: dit verbind mense met mekaar en verskaf toegang tot die werksplek, diensteverskaffers, en vryetydsbesteding. Post-apartheid Suid-Afrika is egter nog steeds vasgevang in ’n nalatenskap van rasseskeiding. Die minderbevoorregtes, wat meestal aan die buitewyke van die stad woon, is geforseerde gebruikers van openbare vervoer, terwyl die neiging (onder die bevoorregtes) om privaatvoertuie te gebruik, aan die toeneem is. Hierdie navorsingsprojek beveel dus aan dat ’n gebalanseerde, geïntegreerde en volhoubare vervoerstelsel bevorder moet word. ’n Sodanige stelsel sal help om die sosio-ekonomiese status van Suid-Afrika te bevorder. Dít kan net bereik word as alle landsburgers gelyke toegang tot ’n gebalanseeerde vervoernetwerk het. As ’n multimode-stelsel dus bevorder word, kan die tekortkominge van die huidige heterogene, nie-geïntegreerde stelsels oorkom word. Indien Suid-Afrika se vervoernetwerk ’n multimodale platform het, kan die landsburgers effektief en doeltreffend vervoer word sonder om die ekonomie, sosiale aangeleenthede of omgewing, tans en in die toekoms, in gedrang in te bring. Suid-Afrika sal boonop, met so ’n platform in plek, ook die nodige stimulus hê om die bestaande hulpbronne optimaal te gebruik. Hierdie navorsingsprojek verskaf ’n (generiese) in-volgorde-benadering om ’n volhoubare, geïntegreerde openbare vervoerstelsel daar te stel. Die doel is om bewustheid van die voordele wat uit ’n multimodale platform spruit, sowel as die nodige stappe vir die uitvoering daarvan, te kweek. Die fokusarea van die navorsing is die Stad van Kaapstad se land-vervoernetwerke. Die Stad het ’n beheerfasiliteit waar vervoerdata versamel word. Dit staan bekend as die vervoer-beheersentrum (TMC: Transport Management Centre). Hierdie fasiliteit word as toonaangewend in die wêreld beskou. Die kenmerkende eienskappe van hierdie fasiliteit bied verder ook ’n goeie vertrekpunt vir die bevordering van ’n multimodale stelsel. Die navorsing in hierdie veld het die volgende bydraende faktore, wat benodig word om die voorstelling te realiseer, geïdentifiseer. In die eerste plek moet die intelligente vervoerstelsels (ITS: Intelligent Transport Systems) geïntegreer word om ’n geïntegreerde volhoubare vervoerstelsel daar te stel. Indien ’n intelligente vervoerskema, gebaseer op tegnologiese inisiatiewe, aangemoedig word, sal die Stad van Kaapstad in die posisie wees om sy vervoerstelsel pro-aktief te bestuur deur meer effektief te monitor wat aangaan en meer akkuraat te voorspel wat in die toekoms mag gebeur. Tweedens moet daar ’n gesentraliseerde databasis geskep word. Met hierdie databasis sal die nodige integrasievereistes vir ’n multimodale vervoerstelsel, bereik word. Inligting kan dan gedeel word tussen privaat- en openbare landvervoer, asook tussen die beleggers en die operateurs van die verskillende vervoermodusse. ’n Voorbeeld van so ’n databasis is in Microsoft Access geskep en die modusse wat deel daarvan uitmaak, is: MyCiti, Metrorail en Golden Arrow Bus Services (GABS). Die data wat hierin vervat is, is histories, maar daar is vir intydse inligting voorsiening gemaak. In die derde plek is die sukses van die Stad van Kaapstad se vervoerstelsel en die ontwikkeling van ’n multimodale stelsel afhanklik van die daarstelling van ’n effektiewe, gevorderde inligtingsstelsel vir pendelaars (ATIS: Advanced Traveller Information Systems). Die idee is om ’n multimodale vervoerstelsel as ’n gerieflike opsie onder pendelaars te bevorder. Dit kan bereik word deur inligting rakende reisbeplanning aan pendelaars daar te stel. Met die verkryging van sodanige kennis sal die pendelaar se weerstand teen verandering ook afneem. Om so ’n multimodale reisbeplanner (JP: Journey Planner) te ontwikkel, is die eenmodaal-netwerke gekombineer om ’n supernetwerk te skep. Dijkstra se algoritme is op die supernetwerk toegepas. Die algoritme is in Microsoft Excel se VBA (Visual Basic for Applications) geprogrammeer en dit bevat die volgende gebruikerskriteria, nl. die begin- en eindpunt, die gebruiker se modes-voorkeur en die gebruiker se gekose optimeringsvoorkeur van tyd of afstand. Ten slotte kan gesê word dat inligting ’n groot rol in die mens se daaglikse lewe en aktiwiteite speel. Daar kan dus geredeneer word dat die sleutel tot suksesvolle vervoerdienste daarin lê om vir ingeligte pendelaars voorsiening te maak. As pendelaars ingelig is oor die stand van die vervoernetwerk maak dit hul houding meer positief. Verder, as pendelaars ook inligting oor reisbeplanning het, kan dit hul gevoel van onsekerheid en vrees jeens (veral) openbare vervoer teenwerk. Met al hierdie inligting tot sy beskikking kan ’n persoon dus sy eie keuses maak en dit lei daartoe dat die persoon meer in beheer voel. As ’n multimodale JP geskep word, voed dit die mens se begeerte vir meer inligting. En met ’n sodanige JP in plek, kan geïntegreerde pendel moontlik die norm word.