The aim of this PhD thesis was to investigate traffic safety and mobility for individuals with hearing loss (HL). Three studies were conducted: 1. a questionnaire survey aimed to evaluate differences in choice of transportation that might be related to HL, 2. a driving simulator study that looked into compensatory strategies and evaluated the efficiency of a tactile signal to alert the driver, and 3. a field study to evaluate these effects in real traffic and to evaluate a navigation system with a supportive tactile signal. The effects of HL discovered in this thesis add to the knowledge and understanding of the influence of HL on traffic safety and mobility. Differences found consistently point to a generally more cautious behavior. Compensatory and coping strategies associated with HL are bound to driving complexity and appear when complexity increases. These strategies include driving at lower speeds, using a more comprehensive visual search behavior and being less engaged in distracting activities. Evaluation of a tactile signal showed that by adding a tactile modality, some driver assistance systems can also be made accessible to drivers with HL. At the same time, the systems might be more effective for all users, since the driver can be more focused on the road. Based on the results in this thesis, drivers with HL cannot be considered an increased traffic safety risk, and there should be no need for adjustments of the requirements of hearing for a license to drive a car. / Syftet med den här doktorsavhandlingen var att undersöka trafiksäkerhet och mobilitet för individer med hörselnedsättning (HN). Tre studier har genomförts: 1. en enkätstudie för att undersöka skillnader i transportvanor relaterade till HN, 2. en körsimulatorstudie for att titta på kompensatoriska strategier och utvärdera effektiviteten i en taktil signal för att påkalla förarens uppmärksamhet och 3. en fältstudie för att undersöka effekterna i riktig trafik samt utvärdera ett navigationssystem med en taktil signal som stöd för navigering. Effekterna av HN som kom fram i denna avhandling bidrar till kunskapen och förståelsen för hur HN påverkar trafiksäkerhet och mobilitet. De funna skillnaderna pekar konsistent mot ett generelltmera försiktigt beteende. Kompensatoriska - och copingstrategier förknippade med HN beror på körkomplexitet och observeras när komplexiteten ökar. Dessa strategier innebär körning med lägre hastighet, mera heltäckande visuell avsökning och mindre engagemang i distraherande uppgifter. Utvärdering av en taktil signal visade att genom att lägga till en taktil modalitet kan vissa förarstödsystem bli tillgängliga även för förare med HN. Samtidigt kan systemen bli mera effektiva för alla användare eftersom föraren då kan fokusera mera på vägen. Baserat på resultaten i den här avhandlingen kan inte förare med HN betraktas som någon förhöjd risk och det bör därmed inte finnas något behov av att justera hörselkraven när det gäller körkortsinnehav.

Målet med examensarbetet har varit att samla information åt ett tekniskt konsultföretag för att öka deras kunskap om autonoma system och fordonskommunikation. Statusen på arbetet kring dessa aktiva säkerhetssystem hos olika aktörer och hur systemen implementeras i dagens och framtidens fordon har undersökts genom omfattande litteraturstudier, intervjuer och marknadsanalyser. De autonoma systemen kan samla information från omgivningen genom sensorer och bidra till ett jämnare trafikflöde, ökad säkerhet, lättare bilar och bättre miljö. Genom fordonskommunikationen kan fordon kommunicera med varandra samt infrastrukturen och garantera en säker bilfärd. År 2030 utgörs innerstaden av autonom, elektrifierad kollektivtrafik för att transportera människor på begäran, samtidigt som personbilar till viss del förbjuds. Potentiella behov för människan i en fullt autonom bil har identifierats och diverse produktutvecklingsmetoder har tillämpats för att utforma två konceptuella lösningar för en framtida bilinteriör. Lösningarna visar interaktionen mellan människa och system eftersom underhållning och bekvämlighet blir viktigt i en fullt autonom bil. Respektive lösning är statsägd och rymmer fyra passagerare. I lösningarna är sittplatserna placerade på ett sätt som underlättar kommunikation mellan passagerarna. Passagerarna kan underhållas eller informeras individuellt eller gemensamt via text, ljud och bild. / The goal with this thesis project has been to collect information for a technical consulting company in order to increase their knowledge about autonomous systems and vehicular communication. The status of how various operators work with active safety systems and how the systems are implemented in current and future vehicles has been investigated through extensive literature studies, interviews and market research. The autonomous systems can collect information from the surrounding through sensors and contribute to better traffic efficiency, increased safety, lighter cars and a better environment. Through vehicle communication, the vehicle can communicate with each other in order to guarantee a safe ride. In 2030 the inner city constitutes of autonomous, electrified public transport to transport people on demand, meanwhile private cars are prohibited. Potential needs for the human in a fully, autonomous car has been identified and various product development methods has been applied in order to develop two conceptual solutions for a future car interior. The solutions show the interaction between human and system since entertainment and comfort becomes important in a fully, autonomous car. Each solution is state-owned and holds four passengers. In the solutions, the seats are placed in regard to facilitate communication between the passengers. The passengers can be entertained or informed individually or collectively by text, sound and images.

« La grande majorité des accidents demeure liée aux comportements dangereux des usagers de la route ». Cet énoncé, lapidaire, fait aujourd’hui figure d’évidence au sein de la communauté des intervenants en sécurité routière. Il repose pourtant sur des prémisses discutables. Le problème le plus fondamental réside dans le fait que la recherche des dernières décennies s’est presque toute entière vouée à l’analyse des seuls aspects défaillants de la conduite (l’accident, les infractions, les erreurs et les fautes de conduite, les conducteurs à risque ou dysfonctionnels, les attitudes et traits de caractère incitant à la conduite dangereuse, etc.). Ce faisant, on a fini par oublier qu’il nous restait encore beaucoup de choses à apprendre sur le fonctionnement usuel de la conduite automobile. Comment, en effet, peut-on escompter élucider tous les rouages de la dynamique accidentelle sans avoir au préalable cerné, et bien compris, les mécanismes de la conduite « ordinaire » ? Comment peut-on parvenir à approfondir notre compréhension des comportements de conduite si l’on fait totalement abstraction de toutes les activités courantes, « normales », auxquelles se livrent les conducteurs lorsqu’ils sont au volant de leur véhicule ? C’est dans la perspective de mieux comprendre les comportements de conduite, dans leur complexité et dans leur diversité, que la présente thèse a été réalisée. Y a plus spécifiquement été examinée la question des habitudes en raison de leur prédominance dans l’activité de la conduite, mais également en raison de leur résistance, des obstacles bien concrets qu’elles sont susceptibles d’opposer à tous ceux qui tentent de modifier les comportements individuels de conduite. Des entrevues en profondeur, menées auprès de trente conducteurs et conductrices âgé(e)s de 17 à 54 ans, devaient permettre de répondre, entre autres, aux questions suivantes : De quoi sont constituées les différentes habitudes en matière de conduite automobile ? Quelle place occupent-elles dans la conduite des individus ? En quoi constituent-elles un frein au changement, à la modification des pratiques adoptées ? Quelles sont les dimensions qui participent à leur installation ? Les résultats de l’analyse ont permis de jeter les bases d’un modèle des comportements de conduite où les sensations corporelles se voient conférer un rôle des plus centraux, et où l’habitude – bien davantage caractérisée par la notion de confort que par celles d’automatisme ou de répétition – concourt non seulement à la pérennité, mais également à la régulation des conduites adoptées sur la route. / “The vast majority of accidents remain related to the dangerous behaviors of road users”. This straightforward statement is now accepted as a truism by the road safety community, although it is based on questionable premises. The most basic problem is that the research done during last decades was almost completely focused on analyzing solely the failing aspects of driving – accidents, traffic offences, driving errors and mistakes, high-risk and dysfunctional drivers, attitudes and psychological traits that may lead to dangerous driving, etc. In so doing, we came to forget that we still have plenty to learn about the art of ordinary driving. How can we expect to address the entire process of road accidents without first having identified, and clearly understood, the mechanisms of “regular” driving? How can we deepen our understanding of driving behaviors if we are completely ignoring all the usual, “normal” activities people do as they are driving their vehicles? This thesis was realized with the view to better understanding the driving behaviors, taking into account their diversity and richness. The study more specifically looked into the issue of habits, as they are a significant aspect of driving behaviors, but also as they are resilient, in that they pose real barriers to all those who are trying to change individual driving behaviors. In-depth interviews with 30 drivers, male and female, aged between 17 and 54, were meant to answer the following questions, among others: What are the different driving habits made of? To what extent do they direct driving behaviors? How do they hamper the change or modification of adopted practices? What are the factors that lead them to set in? The results of the analysis laid the foundations of a driving behaviors model in which body sensations take a central role, and the habit – which is more related to the idea of comfort than to ideas of automatism or repetition – contributes not only to the sustainability, but also to the regulation of the various behaviors adopted on the roads.

La consommation de cannabis et la conduite sous l’influence du cannabis sont des préoccupations grandissantes dans la société d’aujourd’hui. Le but de la présente étude est d’examiner plus en profondeur la relation entre la fréquence de consommation de cannabis chez les jeunes adultes et la prise de risque sur la route. Les participants (n=48) sont tous des hommes âgés de 18 à 26 ans. Ils ont complété une batterie de questionnaires ainsi qu’une tâche sur simulateur de conduite. Les résultats indiquent que la fréquence de consommation de cannabis est associée positivement avec la prise de risque auto rapportée et suggèrent une tendance positive avec les comportements risqués observés lors de la simulation de conduite en laboratoire. Lorsque les différents groupes de consommateurs sont comparés, ceux qui font un usage quotidien ou multihebdomadaire de cannabis semblent prendre plus de risques au volant que ceux qui consomment une fois semaine et moins ou encore une fois par mois et moins. De plus, il semble que plus les individus consomment fréquemment de la marijuana, plus ils ont tendance à adopter des attitudes permissives en lien avec la conduite sous l’influence de cannabis. Les implications quant à l’intervention sont discutées. / Cannabis use and driving under the influence of cannabis have become a growing concern in today’s society. The aim of the present study was to further examine the relationship between the use frequency of cannabis among young adults and on-road risk taking. Participants (n=48) were all men aged between 18 and 26 years old who were asked to complete questionnaires and to perform in a simulation task. Results indicate that the use frequency of cannabis is positively associated with self-report of risky driving and suggest a trend with observed risk taking behaviour during the simulation. When comparing the different cannabis users, participants who consumed daily or multiple times a week seem to take more risk on the road than those who use cannabis once a week or less and less than monthly. Moreover, it seems that marijuana users who consume more frequently have a tendency of adopting more permissive attitudes toward smoking cannabis and taking the wheel. Implications for interventions are discussed.

With increasing costs of fossil fuels and intensified environmental awareness, low carbon vehicles, including hybrid electric vehicles (HEVs), are becoming more popular for car buyers due to their lower running costs. HEVs are sensitive to the driving conditions under which they are used however, and real-world driving can be very different to the legislative test cycles. On the road there are higher speeds, faster accelerations and more changes in speed, plus additional factors that are not taken into account in laboratory tests, all leading to poorer fuel economy. Future trends in the automotive industry are predicted to include a large focus on increased hybridisation of passenger cars in the coming years, so this is an important current research area. The aims of this project were to determine the energy consumption of a HEV in real-world driving, and investigate the differences in this compared to other standard drive cycles, and also compared to testing in laboratory conditions. A second generation Toyota Prius equipped with a GPS (Global Positioning System) data logging system collected driving data while in use by Loughborough University Security over a period of 9 months. The journey data was used for the development of a drive cycle, the Loughborough University Urban Drive Cycle 2 (LUUDC2), representing urban driving around the university campus and local town roads. It will also have a likeness to other similar driving routines. Vehicle testing was carried out on a chassis dynamometer on the real-world LUUDC2 and other existing drive cycles for comparison, including ECE-15, UDDS (Urban Dynamometer Driving Schedule) and Artemis Urban. Comparisons were made between real-world driving test results and chassis dynamometer real-world cycle test results. Comparison was also made with a pure electric vehicle (EV) that was tested in a similar way. To verify the test results and investigate the energy consumption inside the system, a Prius model in Autonomie vehicle simulation software was used. There were two main areas of results outcomes; the first of which was higher fuel consumption on the LUUDC2 compared to other cycles due to cycle effects, with the former having greater accelerations and a more transient speed profile. In a drive cycle acceleration effect study, for the cycle with 80% higher average acceleration than the other the difference in fuel consumption was about 32%, of which around half of this was discovered to be as a result of an increased average acceleration and deceleration rate. Compared to the standard ECE-15 urban drive cycle, fuel consumption was 20% higher on the LUUDC2. The second main area of outcomes is the factors that give greater energy consumption in real-world driving compared to in a laboratory and in simulations being determined and quantified. There was found to be a significant difference in fuel consumption for the HEV of over a third between on-road real-world driving and chassis dynamometer testing on the developed real-world cycle. Contributors to the difference were identified and explored further to quantify their impact. Firstly, validation of the drive cycle accuracy by statistical comparison to the original dataset using acceleration magnitude distributions highlighted that the cycle could be better matched. Chassis dynamometer testing of a new refined cycle showed that this had a significant impact, contributing approximately 16% of the difference to the real-world driving, bringing this gap down to 21%. This showed how important accurate cycle production from the data set is to give a representative and meaningful output. Road gradient was investigated as a possible contributor to the difference. The Prius was driven on repeated circuits of the campus to produce a simplified real-world driving cycle that could be directly linked with the corresponding gradients, which were obtained by surveying the land. This cycle was run on the chassis dynamometer and Autonomie was also used to simulate driving this cycle with and without its gradients. This study showed that gradient had a negligible contribution to fuel consumption of the HEV in the case of a circular route where returning to the start point. A main factor in the difference to real-world driving was found to be the use of climate control auxiliaries with associated ambient temperature. Investigation found this element is estimated to contribute over 15% to the difference in real-world fuel consumption, by running the heater in low temperatures and the air conditioning in high temperatures. This leaves a 6% remainder made up of a collection of other small real-world factors. Equivalent tests carried out in simulations to those carried out on the chassis dynamometer gave 20% lower fuel consumption. This is accounted for by degradation of the test vehicle at approximately 7%, and the other part by inaccuracy of the simulation model. Laboratory testing of the high voltage battery pack found it constituted around 2% of the vehicle degradation factor, plus an additional 5% due to imbalance of the battery cell voltages, on top of the 7% stated above. From this investigation it can be concluded that the driving cycle and environment have a substantial impact of the energy use of a HEV. Therefore they could be better designed by incorporating real-world driving into the development process, for example by basing control strategies on real-world drive cycles. Vehicles would also benefit from being developed for use in a particular application to improve their fuel consumption. Alternatively, factors for each of the contributing elements of real-world driving could be included in published fuel economy figures to give prospective users more representative values.

La phénoménologie, portant à l’expression une intuition eidétique de la spécificité de l’expérience musicale nourrie de la pratique quotidienne de l’instrument et de la fréquentation des œuvres du répertoire classique, doit pouvoir exercer, dans le dialogue avec les neurosciences, une double fonction : critique et positive. D’une part, elle est un révélateur des erreurs de catégorie des récents programmes de réduction de la musique, tantôt aux émotions de base, tantôt à la structure dynamique de la perception du temps, tantôt à un langage de communication non verbale. D’autre part, elle nous a servi à réorienter la recherche vers les conditions neurophysiologiques de l’immersion dans l’univers spirituel de Brahms (et des autres compositeurs) par projection intropathique d’une auto-affection kinesthésique, mettant l’écoute mélomane en résonance avec les tensions et relaxations musculaires du corps musicien accomplissant les gestes producteurs du «son musical». L’auteure, pianiste et chef d’orchestre, retirant l’enseignement philosophique de sa participation à l’équipe de neurophysiologistes du professeur Fadiga de l’Université de Ferrare, dont les travaux ont abouti à la publication d’un critère quantitatif de la «driving force» du chef d’orchestre applicable au jugement esthétique, pose les fondements d’une nouvelle eidétique kinesthésique de l’incarnation, l’empathie, l’intersubjectivité et la noématique musicale. L’anticipation, propriété fondamentale du vivant pour le physiologiste, la protention, structure de distensio animi de la conscience du temps pour le philosophe, sont à la base d’un principe technique intuitivement connu des grands chefs d’orchestre. / By giving expression to an eidetic intuition of the specificity of musical experience enriched by the daily practice of the instrument and familiarity with works from the classical repertoire, phenomenology, in its dialogue with the neurosciences, has to be able to fulfill a double function: both critical and positive. On the one hand, it brings to light the category mistakes inherent in recent programs seeking to reduce music either to basic emotions or else to the dynamic structure of the perception of time or again, to a non-verbal language of communication. On the other hand, it has made it possible for us to reorient ongoing research in the direction of an investigation of the neurophysiological conditions underlying the immersion into the spiritual universe of Brahms (and other composers), and this by way of an intropathic projection of a kinaesthetic auto-affection, establishing a resonance between the music-lovers auditive appreciation and the muscular tensions and relaxations of the musician body accomplishing the gestures productive of his ‘musical sound’. The author, a pianist and orchestral conductor, wants to lay the foundations for an eidetic investigation of our kinaesthetic experience of embodiment, of empathy, of intersubjectivity and of a musical noematics. The present work draws the philosophical lessons of her participation in a team of neurophysiologists, led by Professor Fadiga of the University of Ferrara, whose work led to the recent publication of a quantitative criterion of the driving force of conducting applicable to aesthetic judgment. Anticipation, one of the most fundamental properties of all living being for the physiologist, along with distensio animi, the structure of time consciousness for the philosopher, both lie at the root of a technical principle intuitively comprehended by the world’s great orchestral conductors.

The next generation of intelligent vehicles will evolve from being able to drive autonomously to ones that communicate with other vehicles and execute joint behaviors. Before allowing these vehicles on public roads, we must guarantee that they will not cause accidents. We will apply formal methods to ensure the degree of safety that cannot be assured with simulation or closed-track testing. However, there are challenges that need to be addressed when applying formal verification techniques to cooperative driving systems. This thesis focuses on the techniques that address the following challenges: 1. Automotive applications interact with the physical world in different ways; 2. Cooperative driving systems are time-critical; 3. The problem of state explosion when we apply formal verification to systems with more participants. First, we describe the multiple stack architecture. It combines several stacks, each of which addresses a particular way of interaction with the physical world. The layered structure in each stack makes it possible for engineers to implement cooperative driving applications without being bogged down by the details of low-level devices. Having functions arranged in a layered fashion helps us divide the verification of the whole system into smaller subproblems of independent module verification. Secondly, we present a framework for modeling the protocol systems that uses GPS clocks for synchronization. We introduce the timing stack, which separates a process into two parts: the part modeled as an finite-state machine that controls state transitions and messages exchanges, and the part that determines the exact moment that a timed event should occur. The availability of accurate clocks at different locations allows processes to execute actions simultaneously, reducing interleaving that often arises in systems that use multiple timers to control timed events. With accurate clocks, we create a lock protocol that resolves conflicting merge requests for driver-assisted merging. Thirdly, we introduce stratified probabilistic verification that mitigates state explosion. It greatly improves the probability bound obtained in the original probabilistic verification algorithm. Unlike most techniques that aim at reducing state space, it is a directed state traversal, prioritizing the states that are more likely to be encountered during system execution. When state traversal stops upon depleting the memory, the unexplored states are the ones that are less likely to be reached. We construct a linear program whose solution is the upper bound for the probability of reaching those unexplored states. The stratified algorithm is particularly useful when considering a protocol system that depends on several imperfect components that may fail with small but hard-to-quantify probabilities. In that case, we adopt a compositional approach to verify a collection of components, assuming that the components have inexact probability guarantees. Finally, we present our design of driver-assisted merging. Its design is reasonably simplified by using the multiple stack architecture and GPS clocks. We use a stratified algorithm to show that merging system fails less than once every 5 × 10¹³ merge attempts.

L’objectif de ce travail de recherche consistait à utiliser la réalité virtuelle (simulateur de conduite) afin d'améliorer les capacités attentionnelles de personnes présentant une baisse d’efficience de ces aptitudes (en lien avec l’âge ou la survenue d’un traumatisme crânien) pouvant se répercuter sur la conduite automobile. En référence au modèle de l’attention de Van Zomeren et Brouwer (1994), quatre processus attentionnels (alerte phasique, vigilance, attention sélective et attention divisée) ont été entraînés sur simulateur de conduite lors d’un programme comprenant 9 sessions d’une heure. Un groupe contrôle a effectué un training plus conventionnel sur ordinateur. Les performances des participants (10 patients traumatisés crâniens et 16 personnes âgées de plus de 65 ans) ont été évaluées avant et après le training à partir de trois mesures : une évaluation neuropsychologique, une évaluation sur simulateur de conduite et une évaluation sur route réelle. Le bénéfice de l’entraînement sur les performances aux tests neuropsychologiques s’est avéré limité pour les deux groupes. Concernant l’évaluation sur simulateur, les résultats ont révélé une amélioration des performances plus importante pour les participants entraînés sur simulateur. En revanche, les participants ayant bénéficié du training sur ordinateur ont davantage progressé que ceux entraînés sur simulateur lors de l’évaluation sur route réelle. Les résultats ont été discutés en termes d’approche rééducative et d’automatisation des processus attentionnels. Ce travail permet de conclure quant à la nécessité de poursuivre et d’approfondir les recherches sur la réalité virtuelle et le transfert de l’apprentissage en situation de vie quotidienne / The aim of this research was to investigate the role of the virtual reality in the improvement of attentional processes and driving competence. A driving simulator was used in order to train people with attentional impairments, like Traumatic Brain Injury (TBI) patients or elderly people. The theoretical frame suggested by Van Zomeren and Brouwer (1994) was used in order to train four attentional processes (phasic alert, vigilance, selective attention and divided attention). Ten TBI patients and 16 elderly people entered a 3-week 9-hour training program in which they were randomly allocated to either an experimental (simulator-based training) or control (computer-based training) group. Performance in off-road evaluations (neuropsychological and driving simulator tests) and on-road test were used to assess the driving ability of subjects pre- and post-training. Both groups improved in many neuropsychological evaluations. Significant improvements in driving simulator test were found in favor of the experimental group. However, improvements were greater for the control group regarding the on-road test. Results were discussed in terms of rehabilitation approach and automatic vs control processing theory. This study offers future research possibilities concerning the improvement of knowledge on virtual reality and learning transfer in daily activities

L’objectif de cette thèse était d’étudier les fonctions exécutives dans la maladie de Parkinson et leurs implications dans la conduite automobile. Nous avons mesuré séparément les fonctions de flexibilité mentale et de mise à jour par des tests neuropsychologiques et des tâches sur simulateur de conduite. Nous avons fait l’hypothèse que ces fonctions étaient plus altérées chez les patients et que leurs déficits influençaient la performance de conduite. Trois études ont été réalisées : les deux premières sur simulateur et la dernière sur route avec un véhicule instrumenté. Les résultats de la première étude ont montré un déficit de la fonction de mise à jour chez les patients par rapport aux contrôles. La deuxième étude consistait à tester une seconde fois les conducteurs deux ans après la première étude. En deux ans, la fonction de flexibilité s’est dégradée chez les patients, suggérant que les deux fonctions étudiées ont évolué différemment : la mise à jour étant atteinte plus précocement dans la maladie. Les patients déclaraient également avoir restreint leur conduite. Les résultats de la troisième étude sur route ont permis d’identifier les conducteurs parkinsoniens à « risque » d'être dangereux, i.e. ceux ayant le plus de difficultés en conduite (évaluation conjointe de l’expérimentateur et du moniteur d’auto-école). Les conducteurs à « risque » avaient des performances plus faibles aux tests de mise à jour et de flexiblité par rapport aux conducteurs parkinsoniens sécuritaires. L’ensemble de ces travaux mettent en évidence le rôle essentiel de la mise à jour et de la flexibilité mentale dans la conduite automobile chez des personnes atteintes de la maladie de Parkinson. / The objective of this thesis was to investigate executive functions in Parkinson’s disease and their implications on driving. We have chosen to separately assess mental flexibility and updating information in working memory by neuropsychological tests and driving simulator tasks. We tested the hypothesis that these two executive functions were impaired in patients and that their deficits influenced the driving performance. Three studies were realised: the first two used the driving simulator and the last was performed on-road with an instrumented vehicle. Results of the first study have shown an updating impairment in patients compared to controls. The second study consisted of assessing the drivers a second time two years after the first study. In two years, the flexibility function declined in patients, suggesting that the two selected functions did not change in a similar way: updating is affected earlier in the disease than mental flexibility. Also, patients declared to have restricted their driving. Results of the third on-road study allowed us to identify “at-risk” drivers with Parkinson’s disease, that is to say those having the most driving difficulties (assessment from both experimenter and a driving instructor). At-risk drivers had poorer performances in updating and flexibility tasks compared to “safe” drivers. All of these studies emphasised the essential role of updating and mental flexibility in driving in people with Parkinson’s disease.

Background: The Swedish driving licence test is a criterion-referenced test resulting in a pass or fail. It currently consists of two parts - a theory test with 65 multiple-choice items and a practical driving test where at least 25 minutes are spent driving in traffic. It is a high-stakes test in the sense that the results are used to determine whether the test-taker should be allowed to drive a car without supervision. As the only other requirements for obtaining a licence is a few hours of hazard education (and a short introduction if you intend to drive with a lay instructor) it is important that the test result, in terms of pass or fail, is reliable and valid. If this is not the case it could have detrimental effects on traffic safety. Examining all relevant aspects is beyond the scope of this licentiate thesis so I have focused on reliability. Methods Reliability for both the theoretical and practical test results was examined. As these are very different types of tests the types of reliability examined also differed. In order to examine inter-rater reliability of the driving test 83 examiners were accompanied by one of five selected supervising examiners for a day of tests. All in all 535 tests were conducted with two examiners assessing the same performance. At the end of the day the examiners compared notes and tried to determine the reason for any inconsistencies. Both examiners and students also filled in questionnaires with questions about background and preparation. As for studying decision consistency and decision accuracy of the theory test, three test versions (a total of around 12,000 tests) were examined with the help of methods devised by Subkoviak (Subkoviak, 1976, 1988) and Hanson & Brennan (Brennan, 2004; Hanson & Brennan, 1990). Results The results from two research studies concerning reliability were presented. Study I focused on inter-rater reliability in the driving test and in 93 per cent of cases the examiners made the same assessment. For the tests where their opinions differed there was no correlation to any of the background variables or other variables examined except for three, which had logical explanations and did not constitute a problem. Although there were cases where the differences were due to different stances on matters of interpretation the most common suggested cause was the placement in the car (back seat vs. front seat). Although the supervising examiners gave both praise and criticism as to how the test was carried out the study does not answer the question whether the tests were equal in terms of composition and difficulty. In Study II the focus was on decision consistency and decision accuracy in the theory test. Three versions of the theory tests were examined and, on the whole, found to be fairly similar in terms of item difficulty and score distribution, but the mean was so close to the cut-score (i.e. the score required to pass) that the pass rate differed somewhat between versions. Agreement coefficients were around .80 for all test versions (between .79 and .82 depending on method). Classification accuracy indicated an .87 probability of a correct classification. Conclusion It is important to examine the reliability and validity of the driving licence test since a misclassification can have serious consequences in terms of traffic safety. In the studies included here the rate of agreement between examiners is deemed as satisfactory. It would be preferable if the classification consistency and classification accuracy, as estimated by the methods used, were higher for the theory test, given its importance. While reliability in terms of agreement between raters/examiners or consistency and accuracy of classification are routinely examined in other contexts, such as large-scale educational testing, this is not often done for the driving licence tests. At the same time, the methods used here can be transferred to contexts where such properties are generally not examined. Collecting information about test-takers and examiners, like in Study I, can provide evidence concerning possible bias. Examining to what extent decisions are consistent is one important aspect of collecting evidence that shows that test results can be used to draw conclusions about driver competence. Still, regardless of outcome, validation is a process that never ends. There is always reason to examine various aspects and make further improvements. There are also many other relevant aspects to examine. A prerequisite for the validity of the score interpretation of a criterion-referenced test like this one is that the cut-score is appropriate and the content relevant. This should therefore be the subject of further research as the validation process continues.