Aquaplaning accidents are relatively rare, but could have fatal effects. The task of this master’s thesis is to use data from the Laser Road Surface Tester to detect road sections with risk of aquaplaning. A three-dimensional model based on data from road surface measurements is created using MATLAB (version 6.1). From this general geometrical model of the road, a pond model is produced from which the theoretical risk ponds are detected. A risk pond indication table is fur-ther created. The pond model seems to work well assuming that the data from the road model is correct. Determining limits for depth and length of risk ponds can be made directly by the user. MATLAB code is reasonably easy to understand and this leaves great opportunities for changing different parameters in a simple way. Supplementary research is needed to further improve the risk pond detection model. Collecting data at smaller intervals and with more measurement points would be desirable for achieving better correlation with reality. In a future perspective, it would be wise to port the code to another programming language and this could make the computations faster.

Cell Broadcast is a relatively old technique within the GSM-network which makes it possible to broadcast text messages to one or more cells in the network. As efforts in Sweden have been made to develop both traffic safety and information technology, the automotive telematics market is predicted to grow rapidly in the near future. The characteristics of Cell Broadcast make it especially suitable for automotive telematics services. The main purpose of this thesis is to investigate possible automotive telematics services based on Cell Broadcast and how these services can affect traffic safety. The most important characteristics for Cell Broadcast in the automotive telematics market are close connection to the GSM/UMTS network, location-based information and information of push character. These characteristics allows the mobile operator to offer a number of automotive telematics services based on Cell Broadcast, some of them as service provider and some of them in joint ventures with car and mobile terminal manufacturers.

The United States averages 40,000 traffic fatalities annually. The American Association of State Highway and Transportation Officials (AASHTO) Roadside Design Guide cites run-off-the-road crashes as contributing greatly to this statistic, with about one-third of all traffic deaths [1]. This number has remained relatively constant over the past four decades, and despite a major increase in vehicle miles traveled (VMT), the rate of fatalities per 100 million vehicle miles traveled has declined. However, this relatively large number of run-off-the-road crashes should remain a major concern in all roadway design. The Highway Safety Act of 1966 marks a defining moment in the history of roadside safety [ ]. Before this point, roadways were only designed for motorists who remained on the roadway, with no regard for driver error. As there was no legislation or guidelines concerning roadside design, roadways constructed prior to 1966 are littered with fixed objects directly off of the edge of pavement. Fortunately, many of these roads have reached their thirty year design lives and have become candidates for improvement. The following report examines roadside crashes on nine Atlanta urban arterial roadways. Accident type, severity, and location for all crashes on these were evaluated. It is found roadside collisions with utility poles and trees were more prone to occur at intersection locations than midblock locations. Also for the studied roadway corridors, on average, roadside collisions were more likely to result in serious injury or fatality. Based on these findings initial recommendations are offer for improving clear zone requirements.

Identifying and understanding the relationships between observed driving behavior over long-term periods and corresponding crash involvement rates is paramount to enhancing safety improvement programs and providing useful insights for transportation safety engineers, policy markers, insurance industries, and the public. Unlike previous data collection methods, recent advancement in mobile computing and accuracy of global positioning systems (GPS) allow researchers to monitor driving activities of large fleets of vehicles, for long-time study periods, at great detail. This study investigates the driving patterns of drivers who have and who have not experienced crashes during a 14-month study period using the longitudinally collected GPS data during a six-month Commute Atlanta study. This investigation allows an empirical investigation to assess whether drivers with recent crash experiences exhibit different driving or activity patterns (travel mileage, travel duration, speed, acceleration, speed stability duration, frequency of unfamiliar roadway activities, frequency of turn movement activities, and previous crash location exposures). This study also discusses various techniques of implementing GPS data streams in safety analyses. Finally, this study provides useful guidance for researchers who plan to evaluate the relationships between driver driving behavior and crash risk with large sample data and proposes driving behavior activity exposure metrics of individual drivers for possible safety surrogate measures as well as for driver re-training and education programs.

<p>The purpose of the present study was to examine effects of driver, vehicle, and environment characteristics on Collision Warning System (CWS) design. One hypothesis was made that the capability of collision avoidance would not be same among a driver, vehicle, and environment group with different characteristics. Accident analysis and quantitative analysis was used to examine this hypothesis in terms of ‘risk’ and ‘safety margin’ respectively. Rear-end collision had a stronger focus in the present study. </p><p>As a result of accident analysis, heavy truck showed a higher susceptibility of the fatal rear-end accidents than car and light truck. Also, dry road surface compared to wet or snow, dark condition compared to daylight condition, straight road compared to curved road, level road compared to grade, crest or sag, roadway having more than 5 travel lanes compared to roadway having 2, 3 or 4 travel lanes showed a higher susceptibility of the fatal rear-end accidents. Relative rear-end accidents involvement proportion compared to the other types of collision was used as a measure of susceptibility. </p><p>As a result of quantitative analysis, a significant difference in terms of Required Minimum Warning Distance (RMWD) was made among a different vehicle type and braking system group. However, relatively small difference was made among a different age, gender group in terms of RMWD. Based on the result, breaking performance of vehicle should be regarded as an input variable in the design of CWS, specifically warning timing criteria, was concluded.</p>

Examensarbetet kommer undersöka aktiv ljuddesign för tysta personbilar. Utifrån tidigare forskning om hur elbilen utsätter människor i tätområden för fara på grund av avsaknaden av auditiv information, ska vi utveckla förslag på dynamiska billjud som förhåller sig till trafiksäkerhet, design och minskade ljudföroreningar. Den totala ljudnivån i städer är långt över rekommendationen och följden blir ett hälsoproblem i större städer. Den här undersökningen kommer därför behandla problematiken kring ljudföroreningar i städer och hur elbilen kan sänka den totala ljudnivån och samtidigt bibehålla medvetenheten hos de gående och cyklister som hamnar i riskzonen när bilar inte längre låter lika starkt. Vår gestaltning resulterade i motorljud som inte bara har en varnade effekt på sin omgivning, utan som också minskar ljudföroreningar i jämförelse med förbränningsmotorer. / This degree project will examine active sound design for quiet vehicles. Based on former research wether electric cars expose humans living in urban areas to danger due to the absence of auditive information, we will develop suggestions for dynamic eninge sounds which are related to traffic safety, design and reduced noise pollution. Cities’ overall noise levels are far beyond recommended, and the consequences causes health issues in bigger cities. This paper will therefore discuss the problems with noise pollution in cities, and wether the electric car is capable of reducing the overall sound levels while maintaining pedestrians’ and cyclists’ awareness in traffic by auditive information. Our interpretation resulted in engine sounds which not only contains a causionary effect on it’s surroundings, but also could contribute to the reduction of noise pollution in comparison to combustion engines.

The growth of serious injuries and fatalities resulting from traffic accidents at intersections is one of the main problems in urban areas. Signal control was proposed as an alternative intersection design on rural roads. There were many reasons behind this, the most outstanding of which was the traffic signals can be used as a cost effective tools for traffic management in urban areas. The LHOVRA technique was intended to improve safety and reduce lost time at signalized intersection along high speed roads. The LHOVRA technique is an isolated traffic control strategy in Sweden which is formed from different concepts. This thesis work is aimed to evaluate the LHOVRA technique with a focus on the O-function. Hence, two different scenarios, one with O-function and one without O-function were implemented in the micro traffic simulation software, VISSIM. VISSIM has been used to simulate the traffic situation of the Gamla Övägen – Albrektsvägen intersection by considering the LHOVRA scenario (with O-function) as well as traditional scenario (without O-function) of the intersection. Field measurements were used as input data for VISSIM simulation. The VISSIM simulation model was calibrated to find a close match between simulated and real data. Finally, a comparison of alternatives was carried out based on traffic performance and traffic safety measurements. The simulation experiment results gained by the comparisons were presented a higher time-to-collision value. The higher time-to-collision value the safer situation is. Both delays and travel time were reduced to primary road traffic.

In the present task it is analysed the influence of centralist microprocessor traffic control system for Kaišiadorys – Radviliškis track capasity and traffic safety. It is given a lot of attention to description of the system, infrastructure reconstruction and calculations of the track Kaišiadorys – Radviliškis capasity. In the task it is given the evaluation of Kaišiadorys – Radviliškis track capasity and traffic safety. It is explored the track eploitation problems and perspectives. JSC Lietuvos geležinkeliai could use the calculation results of track capasity and intervals making trains traffic timetables, the calculations and suggestions also could be used making the exploitation plans for I and IX corridors development.

The thesis introduces the concept of ‘sense-making of risk’ (riskförståelse) for the purpose of the theoretical and empirical study of the individual’s sense-making of risk. Particular weight is attached to an examination of the term’s various components, its compass, and the relationship between sense-making of risk and behaviour. The premise is that risk is created and defined by the common conceptions that exist within the framework of a specific social context; the effect is to focus attention on the significance of social and cultural contexts. To provide a full picture of sense-making of risk, and risk behaviour, and to study these phenomena using a variety of methodological perspectives, the data was gathered from both polls and focus-group interviews. It is in the first article, based on a focus-group interview study, that the concept of sense-making of risk is introduced: the empirical results demonstrate that it can be used to chart how young people with similar risk perceptions differ in their understanding of a variety of risks. A theoretical model is proposed that establishes that there are two dimensions to the individual’s sense-making of risk. The second article considers young people’s risk behaviour in traffic milieus. The principal conclusion drawn in this study is that the individual’s sense-making of risk is insufficient to explain behaviour in relation to risk: the spatial context must also be taken into account. The third article focuses on the relationship between place attachment and sense-making of risk, and demonstrates that various aspects of place attachment have implications for the individual’s sense-making of risk. The fourth and final article offers a cluster analysis. The article’s most important result is its refinement of the theoretical concepts.  Structure of meaning is singled out as the basis for the individual’s sense-making of risk. In its empirical application the concept was shown to be useful in studying the behavioural differences between various social groups, since grouping by structure of meaning furnishes an explanation for variations in risk and risk-reducing behaviour. The introductory and concluding chapters assemble the studies’ findings and offer a full account of the concept of sense-making of risk. The thesis’ most important conceptual contribution is to the question of how the individual arrives at a personal sense-making of risk. However, it will fall to future studies to establish the concept’s general applicability by considering its theoretical ramifications and empirical implementation. In this way, sense-making of risk can take its place in a specifically sociological conceptual apparatus that focuses on how the individual relates to risk. / Föreliggande avhandling introducerar begreppet riskförståelse (sense-making of risk) och dess syfte är att teoretiskt och empiriskt studera detta begrepp. Särskild vikt har lagts vid att undersöka riskförståelsens olika beståndsdelar, dess rumsliga dimensioner samt relationen mellan riskförståelse och beteenden. Med utgångspunkt i att risker definieras och skapas med utgångspunkt i gemensamma föreställningar inom ramen för ett specifikt socialt sammanhang fokuseras betydelsen av sociala och kulturella kontexter. Med detta som grund har begreppsutvecklingen i avhandlingen bland annat inspirerats av Karl Weicks och Alfred Schütz teorier om individens meningsskapande. I de olika delstudier som ingår i avhandlingen studeras olika aspekter av individens riskförståelse och risk-/riskreducerande beteenden. Genom att utgå ifrån Weicks teorier om meningsskapande illustrerar riskförståelsebegreppet individens personliga förståelse för olika risker. De normer och värderingar som omger individen i det sociala och rumsligt definierade sammanhang som hon befinner sig i är avgörande för vilken förståelse hon kan skapa för en risk. Genom att använda bland annat Schütz teorier om sociala relationer betydelsen och funktionen av individens meningsstruktur synliggjorts som bas för individens riskförståelse. Meningsstrukturen består av flera olika beståndsdelar och i avhandlingen lyfts fyra av dessa fram: egna erfarenheter, värderingar, platsanknytning och social skiktning. Genom att individen relaterar den risk hon möter till den egna meningsstrukturen skapas förståelse för den specifika risken. Meningsstrukturens funktion är att bistå individen med förenklingar av verkligheten för att göra det möjligt att skapa mening kring olika risker. En viktig aspekt vad gäller meningsstrukturen är att den i hög grad är socialt konstruerad genom socialiseringsprocesser i det specifika rumsliga sammanhang som individen befinner sig i. Detta innebär att individens förståelse av risk relateras till olika sociala och rumsliga sammanhang; individens riskförståelse är således platsbunden. Avhandlingen bygger på fyra delstudier vilka presenteras i artikelform. Datamaterial samlats in genom både enkätundersökningar och fokusgruppsintervjustudier för att undersöka detta fenomen utifrån olika metodologiska perspektiv. I den första artikeln, baserad på en fokusgruppsintervjustudie, introducerades begreppet riskförståelse. De empiriska resultaten visade att begreppet kan användas för att synliggöra hur ungdomar med liknande riskperceptioner skiljer sig åt i sin förståelse av olika risker. En teoretisk modell utformades som beskriver individens riskförståelse med utgångspunkt i två dimensioner. Den första dimensionen relaterade till i vilken grad individens riskförståelse är platsbunden och den andra till om individens riskförståelse främst kan beskrivas som kollektivt eller individuellt orienterad. Empiriskt åskådliggjorde resultaten att ungdomarna i studien uppfattade samma risker som allvarliga men att deras riskförståelse skilde sig åt och att dessa skillnader kunde härledas till boendemiljö. I den andra artikeln studerades ungdomars riskbeteenden i trafiken. I studien gjordes logistiska regressionsanalyser på ett datamaterial hämtat från Trafiksäkerhetsundersökningen 2001. En viktig slutsats från denna studie var att det är viktigt att inte bara ta hänsyn till individens riskförståelse, utan också till rumsliga sammanhang vad gäller att förklara individens beteenden i relation till risk. Den tredje artikeln, som baserades på en fokusgruppsintervjustudie, var en tillämpning av begreppet riskförståelse med avseende på risker i trafiken. Undersökningen fokuserade på relationen mellan platsanknytning och riskförståelse. Studien visade att olika aspekter av platsanknytning har betydelse för individens riskförståelse. Social tillhörighet hade särskilt stor betydelse vad gäller riskförståelse hos de ungdomar som deltog i studien men också de andra dimensioner av platsanknytning som studerades (yttre förhållanden, ömsesidigt beroende och värdegemenskap) hade betydelse för riskförståelse hos respondenterna i studien. I den fjärde delstudien genomfördes klusteranalys på ett datamaterial från undersökningen Samhälle och värderingar 2008. Det viktigaste resultatet från denna studie var den teoretiska begreppsutveckling som presenterades. Denna innebar att meningsstrukturen lyftes fram som bas för individens riskförståelse. Vidare gjordes en operationalisering av individens meningsstruktur, vilken användes för att gruppera individer. Den empiriska tillämpningen visade sig vara användbar vad gäller att studera skillnader i beteenden mellan olika grupper i samhället då gruppering utifrån meningsstruktur bidrog till att förklara skillnader i risk-/riskreducerande beteenden. I kappan förs de olika delstudierna samman och begreppsutvecklingen i fråga om riskförståelse beskrivs. Begreppet är av särskild vikt vad gäller att beskriva hur sociala och rumsliga sammanhang ingår i individens riskförståelse. Den begreppsutveckling som gjorts har också visat att individen baserar sin riskförståelse på en meningsstruktur vilken också kan användas för att undersöka risk- och riskreducerande beteenden. Avhandlingens viktigaste bidrag är den teoretiska begreppsutvecklingen ifråga om hur individen skapar sin personliga riskförståelse. Ytterligare teoretisk begreppsutveckling och empiriska tillämpningar bör dock göras i kommande studier för att säkerställa begreppets generella användbarhet. Genom detta kan riskförståelse bli en viktig del i en specifikt sociologisk begreppsapparat med fokus på hur individen förhåller sig till risk.

The author of the Highway Safety Manual (HSM) Part B developed a predictive method for safety management. A software tool for highway safety system analysis called the SafetyAnalyst is developed basing on HSM Part B. The author describes an effort to evaluate the feasibility of SafetyAnalyst in Oregon. Seven sample highway sections in Oregon are selected to demonstrate the SafetyAnalyst network screening application. The purpose of this research is to assess if the SafetyAnalyst is compatible with current Oregon Department of Transportation (ODOT) databases such as the Highway Inventory Detail Report, Lane Report, etc. The author also presents an effort to identify current data deficiencies and identify a feasible solution for addressing these deficiencies. SafetyAnalyst requires hundreds of input variables. Not all of these variables are included in the current Oregon database. Those input variables that require additional data collection are described as well. This thesis also includes a sensitivity test for input variables to prioritize required variables. Finally, the author determines that the SafetyAnalyst can be used in Oregon. This research also provides a variable priority for the SafetyAnalyst users. / Graduation date: 2012