When developing new active safety systems or improving existing systems, conducting performance evaluations is necessary. By performing these evaluations during early development stages, potential problems can be identified and mitigated before the system moves into the production phase. Testing active safety systems can be difficult since the characteristic scenarios may have complex interactions. Using real vehicles for performing these types of scenarios is difficult, expensive, and potentially dangerous. Alternative methods, such as using inflatable targets, scale models, computer simulations or driving simulators, also suffer from drawbacks. Consequently, using virtual reality as an alternative to the traditional methods has been proposed. In this case, a real vehicle is driven while wearing a head-mounted display that presents the scenario to the driver. This research aims to investigate the potential of such technology. Specifically, this work investigates how the chosen technology affects the driver. This investigation has been conducted through a literature review. A test platform was constructed, and two user studies using normal drivers were performed. The first study focused on the effects of visual time delays on driver behavior. This study revealed that lateral behavior changes with added time delays, whereas longitudinal behavior appears unaffected. The second study investigated how driver behavior is affected by different modes of virtuality. This study demonstrated that drivers perceived mixed reality as more difficult than virtual reality. The main contribution of this work is the detailed understanding of how time delays and different modes of virtuality affect drivers. This is important knowledge for selecting which scenarios are suitable for evaluation using virtual reality. / <p>The series name <em>Linköping Studies in Science and Technology Licentiate Thesis</em> is incorrect. The correct series name is <em>Linköping Studies in Science and Technology Thesis</em>.</p>

Advanced Vehicle Systems promise improved safety and comfort for drivers. Steady advancements in technology are resulting in increasing levels of vehicle automation capabilities, furthering safety benefits. In fact, some of these vehicle automation systems are already deployed and available, but with promised benefits, such systems can potentially change driving behaviors. There is evidence that drivers have increased secondary task engagements while driving with automated vehicle systems, but there is a need for a clearer scientific understanding of any potential correlations between the use of automated vehicle systems and potentially negative driver behaviors. Therefore, this thesis aims to understand the state of knowledge on automated vehicle systems and their possible impact on drivers’ distraction behaviors. I have conducted two systematic literature reviews to examine this question. This thesis reports these reviews and examines the effects of secondary task engagement on driving behaviors such as take-over times, visual attention, trust, and workload, and discusses the implications on driver safety.

Unsafe driving habits increase the severity of roadway accidents. The behaviors that are generally associated with unsafe driving are influenced by drivers and their decision to engage in dangerous habits. In order to solve this problem, Departments of Transportation use roadside safety campaigns. To gain a comprehensive understanding of the effectiveness of these campaigns, this research study captured five different metrics of effectiveness to understand what messages are effective and how to target messages to different groups of people. Since reading and interpreting the messages produces cognitive activation among participants, a neuroimaging technology called functional near-infrared spectroscopy (fNIRS) was used to measure neurocognitive activation as a proxy for response. The fNIRS system captures this cognitive activation by measuring change in oxygenated blood (oxy-Hb). An increase in oxy-Hb is a proxy for increased task engagement. The first journal paper provides an understanding of what types of messages are perceived as effective, are misunderstood, are memorable, are considered inappropriate, and cause the greatest increase in cognitive engagement. Overall, drivers perceive messages to be effective at changing behavior, but particular messages are perceived as more effective than others. Messages about distracted driving and driving without a seat belt, messages that are intended to produce a negative emotional response, and messages with statistics are the behaviors, emotions, and themes that are most likely to be perceived to change driver behavior. Messages about distracted driving and messages about statistics are most likely to be remembered by drivers. In general, drivers do not find messages used in safety campaigns to be inappropriate. Drivers elicit more cognitive attention to signs about distracted driving and signs with a humorous emotion. The second journal considers the effectiveness of these messages with different target demographics by further investigating the first journal's results by different dependent variables, including age, gender, and risky driving habits of the participants. In the second study, the results from the first study are further examined to determine if some campaigns are more effective among different demographics of drivers. The behavioral results indicated that females, drivers over 65, low-risk and high-risk drivers, and urban and rural drivers perceive the safety campaigns as more effective. The neurological data revealed that younger drivers had more activation in the ventrolateral prefrontal cortex, an area known for semantics and word processing, which might indicate more cognitive attention to these types of messages. This study provides a unique application of using neuroimaging techniques to understand driver response to safety messages. The recommendations for an effective safety campaign are to use messages about distracted driving, messages with an emotional stimulus, and messages about statistics. Messages about word play and rhyme are recommended for appealing to younger demographics. / Master of Science / Messages like "New year, new you, use your blinker" and "May the 4th be with you, text I will not" are increasingly used to catch drivers' attention. The development and use of these non-traditional safety messages are distinctly different than messages previously displayed on highway signs because the intent of these messages is to modify driver behavior rather than just provide information. Unfortunately, there is little empirical evidence measuring how effective these messages are at changing driver behavior or guidance on how to target messages for specific groups of people. The goal of this study was to understand what types of non-traditional safety messages are effective and how to target these messages to different target audiences. Roadway collisions are made more severe when the cause of the incident involves dangerous driving habits, such as distracted, impaired, or aggressive driving. The problem is made even more severe by the fact that the habits that make driving dangerous are affected by the driver's decision to engage in risky driving behavior. The solution to this problem is to gain an understanding of driver preferences and response, a research effort this study will address. Reading and interpreting the messages produces cognitive activation among participants. The study uses functional near-infrared spectroscopy (fNIRS), which allows researchers to capture this cognitive activation by measuring change in oxygenated blood (oxy-Hb). This provides not only the ability to gain a more detailed understanding of driver response, but the ability to triangulate this with what drivers perceive as effective in changing driver behavior. In the first study, the participants felt that campaigns targeting distracted driving, messages with a negative emotion, and campaigns about statistics were significantly more effective at changing driver behavior compared to other behaviors, emotions, and themes. The neurological data revealed that drivers respond more to campaigns about distracted driving. However, the neurological data indicates that humorous messages and messages that fit under the theme word play and rhyme elicit a greater cognitive response. The second study furthers the first study and revealed that females, drivers over 65, low-risk and high-risk drivers, and urban and rural drivers perceive the safety campaigns as more effective. The neurological data revealed that younger and older males and older high-risk drivers respond with greater peak oxy-Hb when compared to other groups of people. This study advances the applicability of fNIRS in traffic related studies.

The Type-II dilemma zone refers to the segment of roadway approaching an intersection where drivers have difficulty deciding to stop or proceed through at the onset of the circular yellow (CY) indication. Signalized intersection safety can be improved when the dilemma zone is correctly identified and steps are taken to reduce the likelihood that vehicles are caught in it. This research employs driving simulation as a means to collect driver response data at the onset of the CY indication to better understand and describe the dilemma zone. The data obtained was compared against that from previous experiments documented in the literature and the evidence suggests that driving simulator data is valid for describing driver behavior under the given conditions. Fuzzy logic was proposed as a tool to model driver behavior in the dilemma zone, and three such models were developed to describe driver behavior as it relates to the speed and position of the vehicle. These models were shown to be consistent with previous research on this subject and were able to predict driver behavior with up to 90% accuracy. / Graduation date: 2013

Variable Speed Limits (VSL) are often used to improve traffic conditions on congested motorways. VSL can be implemented as mandatory or advisory. The objective of the thesis isto study in detail the effectiveness of VSL. The focus is on both, design parameters and conditions under which VSL are most effective. The MCS system on the E4 motorway inStockholm is used as a case study. The evaluation was conducted using empirical methods (including aggregate data from microwave sensors and other sources, and disaggregate data from a mobile study), and microscopic traffic simulation. The empirical analysis is based on before and after VSL data, including evaluation of individual measures of performance, and multivariate analysis in the form of the fundamental diagram, and speed-density relationships. The results from the empirical study are mixed with an indication that driver behavior has a strong impact on the effectiveness of the system. The microscopic traffic simulation analysis included the development of a platform for testing VSL and more generally motorway control strategies. The simulation platform was calibrated and validated with the empirical data and includes in addition to VSL, and Automatic Incident Detection (AID) system, the ALINEA ramp metering algorithm. The test-platform allows the testing of different control strategies and various combinations of control strategies, under different scenarios and in a controlled environment. The results from the simulation study indicate that driver compliance is an important factor and VSL performance quickly deteriorates as compliance rate drops. Hence, VSL should be implemented as mandatory instead of advisory. In addition, mandatory VSL can be effective both, under incident and moderately congested conditions. A combined VSL and ramp metering strategy can be most effective in reducing travel time, improving traffic conditions on the motorway. Furthermore, the results indicate that such a strategy also has the least impact on the flows entering the motorway from the ramps. / QC20100630

Μία από τις πιο γοργά αναπτυσσόμενες περιοχές της επιστήμης των υπολογιστών είναι η ανάπτυξη έξυπνων συστημάτων που υποστηρίζουν τις αποφάσεις των χρηστών και παρέχουν ένα ευρύ πεδίο υπηρεσιών. Η εξυπνάδα τους βασίζεται στην παρακολούθηση και αποκωδικοποίηση των αναγκών και την προσομοίωση της συμπεριφοράς του χρήστη. Το αντικείμενο της παρούσας διατριβής είναι η παρουσίαση ενός νέου, αξιόπιστου συστήματος δυναμικής αξιολόγησης της συμπεριφοράς του οδηγού και υποστήριξης αυτού σε πραγματικό χρόνο. Πιο συγκεκριμένα, δίνεται έμφαση στην ανοικτή, προσανατολισμένη προς τις υπηρεσίες (service-oriented) αρχιτεκτονική του, στους κανόνες που το διέπουν και στο υλικό και το λογισμικό που του επιτρέπουν να παρέχει διαλειτουργικές υπηρεσίες. Εφαρμόζεται η συστημική προσέγγιση που αρχίζει με τα στοιχεία εισόδου. Τα στοιχεία αυτά αφορούν βασικά τον οδηγό: προσωπικά στοιχεία, προφίλ, καλούς χειρισμούς κ.ά., το αυτοκίνητο: ταχύτητα, επιτάχυνση, επιβράδυνση, γωνία τιμονιού, αριθμός στροφών κινητήρα, σχέση μετάδοσης στο κιβώτιο ταχυτήτων, μοντέλο και τύπος οχήματος και το περιβάλλον: GPS, RFID, κάμερες, αισθητήρες, ασύρματες και δορυφορικές επικοινωνίες κ.ά. Συνεχίζουμε με την ευφυή - αλγοριθμική, στατιστική κ.λπ. - επεξεργασία αυτών των στοιχείων (α) για να εκτιμήσουμε την τρέχουσα κατάσταση του οδηγού και του οχήματος στις συγκεκριμένες περιβαλλοντικές συνθήκες και (β) για να κατανοήσουμε τη συμπεριφορά και να υποστηρίξουμε παθητικά ή ενεργά τον οδηγό κατά τη διάρκεια ενός ταξιδιού. Παράγουμε πρωτότυπα αποτελέσματα, δηλαδή χρήσιμη πληροφορία και πιθανές συμβουλές προς τον οδηγό του οχήματος, στοιχεία για την συμπεριφορά του οδηγού με σκοπό την περαιτέρω χρήση αυτών των πληροφοριών από άλλους φορείς, όπως ασφαλιστικές, εταιρείες, ελεγκτικά όργανα του κράτους κ.λπ. Βέβαια, οι δυνατότητες που προσφέρονται από το προτεινόμενο σύστημα μπορούν να οδηγήσουν σε οφέλη και για τις ασφαλιστικές εταιρείες οι οποίες καλούνται να εκσυγχρονίζουν συνεχώς τον τρόπο με τον οποίο καθορίζουν το ύψος των ασφαλίστρων. Επιπλέον, το προτεινόμενο σύστημα θα μπορούσε να χρησιμοποιηθεί από εταιρείες που διαθέτουν στόλο οχημάτων, προκειμένου να επαληθεύουν και να ελέγχουν την ικανότητα των οδηγών σε πραγματικό χρόνο. Τέλος, το προτεινόμενο σύστημα θα μπορούσε να χρησιμοποιηθεί από το υπουργείο μεταφορών, την τροχαία, τους φορείς τοπικής διοίκησης κ.ά. / One of the fastest growing areas of computer science is the development of intelligent systems that support user decisions and provide a wide range of services. Their intelligence is based on monitoring and decoding of real needs, as well as the simulation of end user’s behavior. The object of this Thesis is the presentation of a new, integrated system for dynamic evaluation of driver behavior. In particular, we emphasize at its open, service-oriented architecture, the incorporated set of rules and the system hardware and software which allow it to provide interoperability. We apply the systematic approach that begins with the input data plus requirements. These data mainly concern the driver: personal data, profile, good practices etc., the vehicle: speed, acceleration, deceleration, steering angle, engine speed, gear ratio in gearbox, model and type, and the environment: GPS, RFID, cameras, wireless and satellite communications, etc. Then, these data are processed applying an intelligent-algorithmic, statistical etc.- approach in order (a) to evaluate the current state of the driver and the car in certain environmental conditions, and (b) to understand the behavior and passively or actively support the driver during a travel. We produce original results, i.e. useful information and possible recommendations to the driver of the vehicle, data concerning the driver behavior and thus, this information can be further used by others, such as insurance companies, audit institutions of state etc. We place great emphasis on cutting-edge technologies that are applied to achieve the required feedback, parameterization and adaptation of the system. Of course, the capabilities offered by the proposed system can lead to clear benefits for various organizations, like insurance companies, which are required to continually update their price policy, companies that have a fleet of vehicles, in order to verify the ability of the drivers and support them in real time. Finally, the proposed system could be used by the Ministry of Transport, the traffic police, the local authorities etc.

La réalité augmentée (Augmented Reality ou AR) peut potentiellement changer significativement l’expérience utilisateur. Au contraire les applications sur Smartphone ou tablette, les technologies d’affichage tête haute (Head Up Display ouHUD) aujourd’hui sont capables de projeter localement sur une zone du pare-brise ou globalement sur tout le pare-brise. Le conducteur peut alors percevoir l’information directement dans son champ de vision. Ce ne sont pas que les informations basiques comme vitesse ou navigation, le système peut aussi afficher des aides, des indicateurs qui guident l’attention du conducteur vers les dangers possibles. Il existe alors un chalenge scientifique qui est de concevoir des visualisations d’interactions qui s’adaptent en fonction de l’observation de la scène mais aussi en fonction de l’observation du conducteur. Dans le contexte des systèmes d’alerte de collision avec les piétons (Pedestrian Collision Warning System ou PCWS), l’efficacité de la détection du piéton a atteint un niveau élevé grâce à la technologie de vision. Pourtant, les systèmes d’alerte ne s’adaptent pas au conducteur et à la situation, ils deviennent alors une source de distraction et sont souvent négligés par le conducteur. Pour ces raisons, ce travail de thèse consiste à proposer un nouveau concept de PCWS avec l’AR (nommé the AR-PCW system). Premièrement, nous nous concentrons sur l’étude de la conscience de la situation (Situation Awareness ou SA) du conducteur lorsqu’il y a un piéton présent devant le véhicule. Nous proposons une approche expérimentale pour collecter les données qui représentent l’attention du conducteur vis-à-vis du piéton (Driver Awareness of Pedestrian ou DAP) et l’inattention du conducteur vis-à-vis de celui-ci (Driver Unawareness of Pedestrian ou DUP). Ensuite, les algorithmes basées sur les charactéristiques, les modèles d’apprentissage basés sur les modèles discriminants (ex, Support Vector Machine ou SVM) ou génératifs (Hidden Markov Model ou HMM) sont proposés pour estimer le DUP et le DAP. La décision de notre AR-PCW system est effectivement basée sur ce modèle. Deuxièmement, nous proposons les aides ARs pour améliorer le DAP après une étude de l’état de l’art sur les ARs dans le contexte de la conduite automobile. La boite englobante autour du piéton et le panneau d’alerte de danger sont utilisés. Finalement, nous étudions expérimentalement notre système AR-PCW en analysant les effets des aides AR sur le conducteur. Un simulateur de conduite est utilisé et la simulation d’une zone HUD dans la scène virtuelle sont proposés. Vingt-cinq conducteurs de 2 ans de permis de conduite ont participé à l’expérimentation. Les situations ambigües sont créées dans le scénario de conduite afin d’analyser le DAP. Le conducteur doit suivre un véhicule et les piétons apparaissent à différents moments. L’effet des aides AR sur le conducteur est analysé à travers ses performances à réaliser la tâche de poursuite et ses réactions qui engendrent le DAP. Les résultats objectifs et subjectifs montrent que les aides AR sont capables d’améliorer le DAP défini en trois niveaux : perception, vigilance et anticipation. Ce travail de thèse a été financé sur une bourse ministère et a été réalisé dans le cadre des projets FUI18 SERA et Labex MS2T qui sont financé par le Gouvernement Français, à travers le programme « Investissement pour l’avenir » géré par le ANR (Référence ANR-11-IDEX-0004-02). / Augmented reality (AR) can potentially change the driver’s user experience in significant ways. In contrast of the AR applications on smart phones or tablets, the Head-Up-Displays (HUD) technology based on a part or all wind-shield project information directly into the field of vision, so the driver does not have to look down at the instrument which maybe causes to the time-critical event misses. Until now, the HUD designers try to show not only basic information such as speed and navigation commands but also the aids and the annotations that help the driver to see potential dangers. However, what should be displayed and when it has to be displayed are still always the questions in critical driving context. In another context, the pedestrian safety becomes a serious society problem when half of traffic accidents around the world are among pedestrians and cyclists. Several advanced Pedestrian Collision Warning Systems (PCWS) have been proposed to detect pedestrians using the on-board sensors and to inform the driver of their presences. However, most of these systems do not adapt to the driver’s state and can become extremely distracting and annoying when they detect pedestrian. For those reasons, this thesis focuses on proposing a new concept for the PCWS using AR (so called the AR-PCW system). Firstly, for the «When» question, the display decision has to take into account the driver’s states and the critical situations. Therefore, we investigate the modelisation of the driver’s awareness of a pedestrian (DAP) and the driver’s unawareness of a pedestrian (DUP). In order to do that, an experimental approach is proposed to observe and to collect the driving data that present the DAP and the DUP. Then, the feature-based algorithms, the data-driven models based on the discriminative models (e.g. Support Vector Machine) or the generative models (e.g. Hidden Markov Model) are proposed to recognize the DAP and the DUP. Secondly, for the «What» question, our proposition is inspired by the state-of-the-art on the AR in the driving context. The dynamic bounding-box surrounding the pedestrian and the static danger panel are used as the visual aids. Finally, in this thesis, we study experimentally the benefits and the costs of the proposed AR-PCW system and the effects of the aids on the driver. A fixed-based driving simulator is used. A limited display zone on screen is proposed to simulate the HUD. Twenty five healthy middle-aged licensed drivers in ambiguous driving scenarios are explored. Indeed, the heading-car following is used as the main driving task whereas twenty three pedestrians appear in the circuit at different moment and with different behaviors. The car-follow task performance and the awareness of pedestrian are then accessed through the driver actions. The objective results as well as the subjective results show that the visual aids can enhance the driver’s awareness of a pedestrian which is defined with three levels: perception, vigilance and anticipation. This work has been funded by a Ministry scholarship and was carried out in the framework of the FUI18 SERA project, and the Labex MS2T which is funded by the French Government, through the program ”Investments for the future” managed by the National Agency for Research (Reference ANR-11-IDEX-0004-02).

<p>  </p> <p>Highway workers are required to work close to moving traffic during road construction and maintenance activities, which exposes them to the risk of being struck by a distracted driver or intruding vehicle. In addition, work zones disturb the usual traffic flow and patterns due to changes in the existing geometric layout of a roadway, and this is also problematic for the drivers as they must navigate a layout of signs, barrels, and lane changes while keeping the vehicle in control. Moreover, late-night tasks, reckless driving, inconsistent work zones, drunk driving, and increased vehicle miles traveled are some of the additional causes of work zone incidents in the United States. Nationwide, around 40,000 accidents occur each year in highway work zones due to vehicle intrusion into the work zone and have steadily increased during the past ten years. Most often, the driver and passenger of the vehicle are the victims of such accidents. The resulting fatalities, injuries, and property damage due to such incidents lead to significant expenses, prolonged travel delays, and potential damage to expensive products in transit.</p> <p>While traditional safety precautions (e.g., truck-mounted attenuators, rumble strips, speed monitoring displays) can help enhance work zone safety, the number of work zone intrusions calls for designing and implementing emerging intrusion alert technologies to warn drivers and workers when errant vehicles intrude into the work zone. Several state Departments of Transportation (DOTs) have begun examining the use of intrusion alert technologies to mitigate work zone intrusions. While previous studies examined the general effectiveness (e.g., sound levels, work zone coverage, deployment characteristics, etc.) of these technologies in both controlled and active construction and maintenance work zones, there are still significant research gaps in investigating how well these intrusion technologies alert the driver and workers, and no documented best practices are available for transportation agencies and DOTs interested in implementing them. In addition, these technologies have been through many improvements and modifications, and further research is imperative to ascertain their chances of acceptance by workers and contractors.</p> <p>To address these gaps, this thesis focuses on (a) empirically examining the effectiveness, implications, and practices of four commercially available intrusion technologies in enhancing work zone safety through various field tests and surveys, and (b) empirically investigating the effectiveness of these technologies considering drivers’ cognitive processing (perception -reaction time) and responses in case of work zone intrusion. The findings of this research study provide detailed information on the identification and testing procedures of technologies and offer guidelines and recommendations for adopting these technologies for practitioners and professionals in the highway construction sector. The proposed decision-making matrix and multi-criteria decision-making framework are based on the empirical data obtained from the various field experiments, literature review, and evaluation survey. This study also provides valuable insights into the overall effectiveness (i.e., by considering functional characteristics, associated drivers’ responses and reactions, and current implementation) of commercially available intrusion technologies to incorporate required modifications in designing and implementing these technologies to enhance work zone safety. The long-term outcome of this study is to significantly reduce the injuries and fatalities in highway maintenance work zones in Indiana and across the country.</p>

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