Ao longo das últimas décadas, o paradigma de sistemas críticos em segurança vem sofrendo transformações como forma de se adequar às novas necessidades demandadas, tais como redução de custos e aumento da produtividade. No Sistema de Gerenciamento de Tráfego Aéreo, esta transformação é preconizada pelo paradigma CNS/ATM (Communication, Navigation, Surveillance / Air Traffic Management), baseado no uso de novas tecnologias digitais, sobretudo satélites, aplicadas à comunicação, à vigilância, à navegação e ao gerenciamento do tráfego aéreo. O CNS/ATM visa reduzir as restrições do atual paradigma de tráfego aéreo como forma de atender sua crescente demanda, mantendo (ou melhorando) os atuais níveis de segurança. Porém, esta mudança de paradigma traz consigo novos desafios e necessidades, sobretudo, quanto à forma de se avaliar os sistemas resultantes. Em face destes novos desafios e problemas enfrentados, este trabalho propôs um método de avaliação de risco, constituído pela união dos métodos \"absoluto\" e \"relativo\" preconizados pela Organização da Aviação Civil Internacional (OACI), pelo emprego do formalismo das redes de Petri Fluidas e Estocásticas (RPFE) na modelagem dos sistemas, e pela comparação entre os valores de métricas de segurança estimados para o sistema avaliado e para um sistema legado. Este método foi aplicado para avaliar a segurança na mudança do atual paradigma de vigilância aérea, baseado em equipamentos Radar, para o paradigma de Vigilância Dependente Automática por Radiodifusão (ADS-B). Como conclusões, o método proposto mostrou-se promissor para avaliar a segurança de sistemas baseados nos atuais paradigmas de sistema críticos em segurança, especialmente o CNS/ATM, onde o formalismo das RPFE proporcionou modelar suas principais características, e a simulação por eventos discretos permitiu estimar as métricas desejadas. Além disso, a ADS-B mostrou-se uma aplicação viável para a vigilância no Sistema de Controle de Tráfego Aéreo, sendo capaz de reduzir o nível de exposição das aeronaves a eventos de perda de separação e, assim, melhorar os níveis de segurança do tráfego aéreo. / In last decades, the safety critical systems paradigm has changing to adapt itself to new necessities, such as costs reduction and productivity demand growth. In the Air Traffic System, those changes are ruled by CNS/ATM paradigm (Communication, Navigation, Surveillance / Air Traffic Management), based on new digital Technologies, mainly Satellites, applied to Communication, Surveillance, Navigation and Air Traffic Management. CNS/ATM intends to reduce the restrictions of current air traffic paradigm, enabling the growth of air traffic capacity without affecting current safety levels. However, this new paradigm brings together new challenges and needs, mainly related to safety assessment. In face of these new challenges, this work proposed a method of risk assessment constituted by the union of the \"absolute\" and \"relative\" assessment methods adopted by the International Civil Aviation Organization (ICAO), by modeling systems using Fluid Stochastic Petri Nets (FSPN) formalism, and by comparison between safety metrics obtained from proposed and legacy system simulations. This method was applied to assess a new concept of air traffic surveillance, named \"Automatic Dependent Surveillance - Broadcasting\" (ADS-B). As main conclusions, the proposed method was promising to assess system safety properties based on current safety critical system paradigm, especially the CNS/ATM, where FSPN formalism provided important modeling capabilities and discrete event simulation allowed estimating the desired safety metric. Besides, ADS-B has meaningfully reduced the separation losses risks and, therefore, it could be used to air traffic control surveillance system to improve capacity and/or safety levels of air traffic system.

<p>Основни предмет истраживања докторске дисертације<br />представљали су рачунарски модели за анализу динамичких<br />карактеристика кретања мотоцикла у функцији повећања безбедности<br />саобраћаја. Значајан удео чине и оргиналана експериментална<br />истраживања са опремом која је прилагођена испитивањима, како у<br />статичко-динамичким лабораторијским условима, тако и у сложеним<br />условима путних испитивања.<br />У oквиру циља дефинисања страдања мотоциклиста дат је<br />осврт на проблематику безбедности мотоциклиста у саобраћају,<br />стања и тенденције, гледано и анализирано на глобалном нивоу,<br />преко специфичности у појединим ширим географским регионима,<br />закључно са стањем у Републици Србији.<br />Као значајан аспект је наведена и приказана конструкција<br />мотоцикла у целини, при чему указано на значај сваког система, са<br />посебним освртом на рам мотоцикла и његову интеракцију са<br />системима ослањања и управљања.<br />На бази добијених резултата динамичких параметара кретања<br />мотоцикла, идентификовани су показатељи динамичког понашања<br />мотоцикла за следеће режиме: кочења, залета, кретања константном<br />брзином, режима осциловања, као и за режиме изражене интеракције<br />динамичких равни.</p> / <p>Osnovni predmet istraživanja doktorske disertacije<br />predstavljali su računarski modeli za analizu dinamičkih<br />karakteristika kretanja motocikla u funkciji povećanja bezbednosti<br />saobraćaja. Značajan udeo čine i orginalana eksperimentalna<br />istraživanja sa opremom koja je prilagođena ispitivanjima, kako u<br />statičko-dinamičkim laboratorijskim uslovima, tako i u složenim<br />uslovima putnih ispitivanja.<br />U okviru cilja definisanja stradanja motociklista dat je<br />osvrt na problematiku bezbednosti motociklista u saobraćaju,<br />stanja i tendencije, gledano i analizirano na globalnom nivou,<br />preko specifičnosti u pojedinim širim geografskim regionima,<br />zaključno sa stanjem u Republici Srbiji.<br />Kao značajan aspekt je navedena i prikazana konstrukcija<br />motocikla u celini, pri čemu ukazano na značaj svakog sistema, sa<br />posebnim osvrtom na ram motocikla i njegovu interakciju sa<br />sistemima oslanjanja i upravljanja.<br />Na bazi dobijenih rezultata dinamičkih parametara kretanja<br />motocikla, identifikovani su pokazatelji dinamičkog ponašanja<br />motocikla za sledeće režime: kočenja, zaleta, kretanja konstantnom<br />brzinom, režima oscilovanja, kao i za režime izražene interakcije<br />dinamičkih ravni.</p> / <p>The basic researching subject of this dissertation were computer<br />models used for the analysis, of motorcycle motion dynamic characteristics,<br />in the function of traffic safety increasement. Significant share also have<br />had the original experimental researching, by implementing equipment<br />which was specifically adjusted for thе researching both in static and<br />dynamic laboratory conditions and also in complex conditions of road<br />examinations.<br />With the aim to define fatal injuries of drivers of the motorcycles a<br />specific attention was given to driver&#39;s safety in traffic, driver&rsquo;s conditions<br />and tendencies, which were examined and analysed on global level,<br />considering specific factors in the wide geographic regions, concluding with<br />the actual state in the Republic of Serbia.<br />As one of significant aspects herein is quoted and presented entire<br />design of motorcycle, indicated a significance of each system, with the<br />special remarks on motorcycle&rsquo;s frame and it&rsquo;s interaction with suspension<br />and steering system.<br />On the basis of obtained results of motorcycle motion dynamic<br />parameters, a key indicators of dynamic behaviour of motorcycle were<br />identified for the following working regimes: braking, accelerating, constant<br />speed motion, oscillation regimes, and also for the regimes of exposed<br />interaction of dynamic planes.</p>

<p>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. </p><p>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. </p><p>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. </p><p>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.</p>

<p>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. </p><p>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.</p>

<p>Att framföra ett utryckningsfordon skiljer sig från att framföra en vanlig bil bland annat för de större friheter gällande trafikregler utryckningsförarna har. Dessa inkluderar både rätten att köra i högre hastigheter än annan trafik, men även möjligheten att kräva fri väg från andra trafikanter. Detta skapar en speciell interaktion mellan trafikanterna i trafiken där utryckningsfordonet kan ses som en lagligt olaglig agent. Avsaknaden på restriktioner gör dock körningen helt beroende på de enskilda utryckningsförarnas bedömning kring körbeteende. Trots det finns det inga nationella riktlinjer i Sverige fällande utbildning av utryckningsförare.</p><p>Den här studien undersökte normer och värderingar kring trafiksäkerhet hos operativ personal inom en ambulansorganisation. Semistrukturerade intervjuer genomfördes vilka var fokuserade på ett antal faktorer som förväntades kunna påverka trafiksäkerheten.</p><p>En tendens att se andra trafikanter som skyldiga för farliga situationer observerades, så väl som effekten olika uppdrag har på körningen, ett fenomen tidigare identifierat som ”red mist” (Dorn & Brown, 2003). Körningen ansågs vara ett känsligt ämne att kritisera och kollegors körstil sågs delvis bero på individuella skillnader. En påverkan på körningen av SOS Alarm påvisas samt att förarutbildningar nedprioriterats inom organisationen. En positiv attityd mot nationella riktlinjer som ett sätt att garantera förarutbildning observerades. Studien öppnar upp för ett flertal framtida studier vilka diskuteras.</p> / <p>Drivers of emergency vehicles (EV) are agents in the traffic system that by law are permitted to perform actions which are illegal for other road users. Not only can EV drivers legally drive above the speed limit, but they can also demand right of way by the use of warning lights and sirens. The lack of restrictions leaves the driving solely dependent on the judgment of each EV driver. Thus, the drivers should be well trained not just in driving skills but specifically in terms of risk assessment and self-assessment. However, there are no national guidelines in Sweden on training of EV drivers.</p><p>This study investigated the traffic safety norms among some ambulance drivers in Sweden. Semi-structured interviews were conducted focused on factors deemed important for traffic safety.</p><p>A tendency to attribute the reasons for risky situation to other drivers was found, as well as the presence of the condition dubbed “red mist” (Dorn & Brown, 2003). Driving was considered a sensitive matter in terms of critiquing and driving behaviour is partly attributed to individual differences. A positive attitude towards national guidelines was observed, as a way to ensure the sufficient EV driver training quality. A broader view of patient safety during pre-hospital health care is proposed to include EV transportation requirements.</p>

In roadway projects, design exceptions are implemented when the project site consists of one or more substandard design elements. The objective of this thesis is to conduct an initial investigation for a monitoring program for the safety performance of design exceptions in Georgia. A total of 467 projects containing design exceptions were reported in Georgia from 1995 to 2011, and from this crash data for 179 projects from 2003 to 2008 were sampled. The crash data collected in this research pertains to all roadway segments within the projects and is not necessarily related to the design exceptions. Future efforts will be required to explore potential connections between the crash rates and design exceptions. The annual crash results generally revealed a high variability and randomness in the data. For this reason, the average 3-year crash frequencies before design exception approval date and after it were calculated to determine the safety performance for projects containing design exceptions. A method for determining expected results using the Highway Safety Manual (HSM) predictive method is also discussed. The findings will be used to guide future research on design exceptions and mitigation measures to improve roadway safety.

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. 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. 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.

The aim of the present study was to estimate the correlation between Euro NCAP pedestrian rating scores and injury outcome in real-life car to pedestrian crashes, with special focus on long-term disability. The study also surveyed most frequently injured body regions and risk differences for specific elements of pedestrians hit by cars. Another aim was to determine whether Brake Assist systems affect the injury outcome in real-life car to pedestrian crashes and to estimate the effect in injury reduction of a high Euro NCAP ranking score combined with Brake Assist. In the current study, the Euro NCAP pedestrian scoring was compared with the real-life outcome in pedestrian crashes that occurred in Sweden 2003-2010. The real-life crash data was obtained from the data acquisition system STRADA, which combines police records and hospital admission data. The medical data consisted of International Statistical Classification of Diseases and Related Health Problems (ICD) diagnoses and Abbreviated Injury Scale (AIS) scoring. In all approximately 500 pedestrians submitted to hospital were included in the study. Each car model was coded according to Euro NCAP pedestrian scores. In addition, the presence or absence of Brake Assist (BA) was coded for each car involved. Pedestrians were grouped according to associated car scoring. Injury outcomes were analyzed with AIS and, at victim level, with permanent medical impairment. This was done by translating the injury scores for each individual to Risk of Serious Consequences (RSC) at 1, 5 and 10% level of medical disability or more. This indicates the total risk of a medical disability for each victim, given the severity and location of injuries. The mean RSC (mrsc) was then calculated for each pedestrian group and t-tests were conducted to ensure statistically significant differences in mrsc between groups. The results showed a significant reduction of injury severity for pedestrians hit by cars with better pedestrian scoring, although pedestrians hit by cars with a high score (three or four stars) could not be studied, due to lack of cases. The reduction of RSC for pedestrians hit by medium performing (two-star) cars in comparison with pedestrians hit by low performing (one-star) cars was 12, 19 and 28% for 1 ,5 and 10% of medical impairment or more, respectively. These results applied to speed limits up to 90 km/h. In urban areas with speed limits up to 50 km/h the reduction of RSC was 17, 26 and 38% for 1, 5 and 10% of medical impairment or more, respectively. Car to pedestrian crashes was most common at speed limits up to 50 km/h and leg, arm and head were the most frequently injured body regions. RSC for pedestrians hit by cars with Brake Assist was not statistically significant lower than for pedestrians hit by cars without Brake Assist. RSC for pedestrians hit by two-star cars with Brake Assist was 19, 31 and 46% lower for 1, 5 and 10% of medical impairment or more, respectively, compared to pedestrians hit by one-star cars without Brake Assist. A significant correlation between Euro NCAP pedestrian score and injury outcome in real-life car to pedestrian crashes was found. The injury reduction was found to be larger for higher severity and level of permanent medical impairment. Car to pedestrian crashes was most common at lower speed zones. Leg, arm and head were the most frequently injured body regions. Brake Assist had no statistically significant effect measured in RSC on car to pedestrian crashes in this material. A high Euro NCAP scoring combined with Brake Assist was shown to give a high effect in reduction of RSC for pedestrians. / Syftet med denna studie var att uppskatta korrelationen mellan Euro NCAPs testresultat för fotgängarskydd och skadeutfall i verkliga olyckor med fotgängare och personbilar, med särskilt fokus på skador som ger medicinsk invaliditet. I studien kartlades även de mest frekvent skadade kroppsregionerna och riskskillnader för särskilda faktorer för fotgängare påkörda av personbilar. Studien syftar dessutom till att undersöka bromsassistanssystems påverkan av skadeutfallet för fotgängare i verkliga olyckor med personbil och att uppskatta den skadereducerande effekten av en hög Euro NCAP-poäng kombinerat med en bromsassistansutrustning. I denna studie var Euro NCAPs fotgängarskyddspoäng jämförd mot skadeutfallet i verkliga olyckor som skett i Sverige 2003-2010. Data från verkliga olyckor inhämtades från databasen STRADA (Swedish Traffic Accident Data Acquisition) som kombinerar polis- och sjukvårdsrapporterad data. De medicinska data innehåller diagnoser av typen ICD (International Statistical Classification of Diseases and Related Health Problems) och värden för AIS (Abbreviated Injury Scale). I helhet var omkring 500 fotgängare inkluderade i studien. Varje enskild personbilmodell kodades enligt Euro NCAPs fotgängarskyddspoäng. Dessutom kodades förekomst eller avsaknad av bromsassistansutrustning för varje enskild personbil inkluderad i studien. Fotgängarna grupperades enligt påkörande personbils fotgängarskyddspoäng. Skadeutfallet analyserades med AIS, på individnivå och med medicinsk invaliditet. Detta gjordes genom översättning av skadeutfall för varje fotgängare till risk för allvarliga konsekvenser (RSC, Risk of Serious Consequences) på 1, 5 och 10 % medicinsk invaliditet eller mer. Detta påvisar den totala risken för medicinsk invaliditet med hänsyn till skadegrad och -lokalisering. Medelvärdet av RSC (mrsc) beräknades sedan för varje fotgängargrupp och t-test utfördes för att säkerställa statistiskt signifikanta skillnader mellan gruppernas mrsc. Resultaten visade en signifikant skadereduktion för fotgängare påkörda av personbilar med en högre fotgängarskyddspoäng, trots att fotgängarolyckor med personbilar som har hög poäng (stjärnbetyg tre och fyra) inte kunde studeras på grund av fåtaligt antal olycksfall. Reduktionen av RCS för fotgängare påkörda av medelpresterande (stjärnbetyg två) personbilar i jämförelse med fotgängare påkörda av lågpresterande (stjärnbetyg ett) personbilar var 12, 19 och 28 % för 1, 5 respektive 10 % medicinsk invaliditet eller mer. Dessa resultat gäller olyckor på vägar med hastighetsgräns upp till 90 km/h. I stadsmiljö med hastighetsgräns upp till 50 km/h var reduktionen av RSC 17, 26 och 38 % för 1, 5 respektive 10 % medicinsk invaliditet eller mer. Fotgängarolyckor med personbil var vanligast på vägar med hastighetsgräns upp till 50 km/h och ben, arm och huvud var de mest frekvent skadade kroppsregionerna. RSC för fotgängare påkörda av personbilar utrustade med bromsassistans var inte statistiskt signifikant lägre än för fotgängare påkörda av personbilar utan bromsassistansutrustning. RSC för fotgängare påkörda av tvåstjärniga personbilar utrustade med bromsassistans var 19, 31 och 46 % lägre för 1, 5 respektive 10 % medicinsk invaliditet eller mer jämfört med fotgängare påkörda av enstjärniga personbilar utan bromsassistansutrustning. En signifikant korrelation mellan Euro NCAPs fotgängarpoäng och skadeutfall i verkliga fotgängarolyckor med personbil påträffades. Skadereduktionen visade sig vara högre för högre skadegrad och nivå av medicinsk invaliditet. Det var vanligare att personbilar kör på fotgängare på vägar med lägre hastighetsgräns. Ben, arm och huvud var de mest frekvent skadade kroppsregionerna. Bromsassistans hade inte en statistiskt signifikant effekt mätt i RSC för fotgängarolyckor i detta material. En hög Euro NCAP poäng kombinerat med bromsassistansutrustning visade sig ge en hög effekt av att reducera fotgängares RSC.

Studiens syfte är att undersöka hur det nationella målet för trafiksäkerhet går att följa upp på länsnivå via befintlig statistik från polis och sjukvård. Ger de två källorna en likartad bild av förändringen av antalet vägtrafikskadade under den gångna tjugoårsperioden? Undersök- ningen omfattar personer som skadats och överlevt vägtrafikolyckor i Västmanlands län. Data från 1989/1990 respektive 2008/2009 jämförs. De två statistikkällorna ger en likartad bild av förändringen av antalet vägtrafikskadade bilister, motorcyklister och mopedister. Skillnaderna är däremot stora beträffande gång- trafikanter och cyklister. Antalet skadade personer registrerade av sjukvården i länet har minskat under den studerade tidsperioden. Det beror på att antalet skadade gångtrafikanter och cyklister har blivit färre. På grund av förändringar inom sjukvården kan minskningen inte kvantifieras. Det lägre antalet frakturer, främst hos gångtrafikanter men även hos cyklister, visar att det varit en minskning. Antalet skadade bilister har däremot blivit fler, men de skadas lindrigare än 1989/1990. Gruppen allvarligt skadade bilister (ISS &gt; 8) har dock ökat. För perioden 1997 – 2009 har det inte funnits något nationellt definierat trafiksäkerhetsmål för allvarligt skadade. Enligt polisens statistik är antalet svårt skadade vägtrafikanter i länet oförändrat under perioden. Om allvarligt skadad i sjukvårdens mätning definieras som inlagd på sjukhus har antalet allvarligt skadade under perioden minskat med 27 %. Antalet allvarligt skadade definierat som ISS &gt; 8 är oförändrat. / The purpose of the study is to investigate the extent to which it is possible to make a follow- up on the regional level of the national road safety target by using existing police and hospital statistics. Do the two sources provide a similar picture of the changes of the number of persons injured in road traffic accidents during the past twenty years? The survey covers persons injured but survived in road accidents in the county of Västmanland. 2008/2009 figures are compared with 1989/1990 figures. Both sets of statistics provide a similar picture of the changes with regard to the number of injured motorists, motorcyclists and moped drivers. However, concerning pedestrians and cyclists there are significant differences. During the time period being studied, the number of injured persons registered by the hospitals of the county has decreased. This is due to the fact that the number of pedestrians and cyclists injured has decreased. However, it is due to structural changes of the health care difficult to quantify the reduction. The lower number fractures, primarily of pedestrians but also of cyclists, shows that there has been a decrease. On the contrary, the number of injured motorists has increased, but their injuries are less serious than in 1989/1990. However, the number of those motorists with serious injuries (ISS &gt; 8) has increased. For the period 1997 – 2009 there has not had an established national target for the number of seriously injured. According to police statistics, the number of severely injured road users in the county has remained unchanged during the time period being studied. If those being hospitalized in the medical statistics are defined as seriously injured, the number of seriously injured has decreased with 27 %. However, if seriously injured is defined as those with ISS &gt; 8, the number has remained unchanged.

Utgångspunkten i mina arbeten om barn och trafik har varit trafiksäkerheten som ett genomgripande samhällsproblem, med barnens utsatta läge i fokus. Arbetet är uppdelat i två delar, där ett examensarbete på C-nivå, som är en översikt, utgör Del I. Del II utgörs av detta examensarbete på D-nivå och består av en empirisk undersökning om förskolebarns trafikförståelse. Syftet med föreliggande studie har varit att undersöka femåriga förskolebarns trafikförståelse utifrån tre olika aktörers perspektiv: barnens, förskolans och föräldrarnas. De frågeställningar som studerades var: vilka föreställningar som barnen har om trafik; hur barnen har tillägnat sig dessa föreställningar; hur barnen uppträder i trafiken samt hur förskolepersonalen och föräldrar arbetar med barnens trafikfostran. För att få svar på frågeställningarna genomfördes en fallstudie på en förskola där åtta barn, barnens två förskollärare samt tre föräldrar intervjuades. Dessutom observerades barnen under en trafikutflykt och deras trafikteckningar analyserades. Resultatet pekar på att förskolebarnen hade tillägnat sig såväl kunskaper som missförstånd om trafiken. Barnen uppfattade att trafik i första hand är motorfordon och vägar men såg inte sig själva som en del av trafiken. De kände till att trafiken har ett inneboende regelsystem, men förstod inte i samma utsträckning upphovet och orsaken till detsamma. Barnen visade stort intresse för trafiksignaler, men alla barn greppade inte innebörden av den gula färgen. Barnen i denna studie förstod att vägmärken har en symbolisk innebörd, där märkena med abstrakta symboler var svårast att tolka korrekt. Svårigheter med att särskilja höger och vänster framträdde också i studien. Med avseende på cykelhjälmsanvändning ansåg barnen att hjälmen endast hade till uppgift att skydda dem vid osäker cykling. Barnen hade inhämtat sina kunskaper och föreställningar från många olika, och ibland oväntade källor, huvudsakligen hemmet och förskolan. Barnens observerade vistelse i trafiken förflöt smidigt, där förskolans användning av reflexvästar och grupperingarna vid promenader framstod som invanda och användbara rutiner. Förskolans och hemmets trafikfostran genomfördes som praktisk träning i verklig trafikmiljö, företrädesvis genom promenader, bussresor och cykling. På förskolan var den vuxne en större auktoritet i trafiken än som annars är brukligt. Ibland arbetade förskolan med osynliga gränsdragningar som ett pedagogiskt verktyg för att skydda barnen i trafiken. / Traffic safety, viewed as a radical community problem, has been the starting-point in this work, with children’s vulnerable position in focus. This work is divided into two parts. Part I is an examination paper on C-level, consisting of a survey within this field. Part II consists of this examination paper on D-level, an empirical study about pre-school children’s understanding of traffic. The aim of the present work has been to study five-year-old pre-school children’s understanding of traffic, as viewed from the perspective of three different groups, the children, the pre-school teachers and the parents. The questions at issue were: the children’s conceptions of traffic and how those conceptions have been acquired, the children’s conduct in traffic, and how pre-school teachers and parents work with children’s traffic training. To answer those questions a case study was accomplished at a pre-school, where eight children, two pre-school teachers and three parents were interviewed. Moreover, I made a field study of the children during their walks in traffic and analyzed their traffic drawings. The results show that the pre-school children had acquired knowledge as well as misunderstandings about traffic. The children understood traffic as consisting of motor vehicles and roads but did not comprehend themselves as a traffic element. They knew that traffic has an inherent system of rules but did not to the same extent understand the origin or cause of those rules. The children were deeply interested in traffic lights but all children did not grasp the meaning of the yellow light. The children in my study understood that road signs have a symbolic message and road signs with abstract symbols were the most difficult to interpret correctly. Difficulties in distinguishing between right and left also appeared in the study. In regards to the use of bicycle helmets the children believed the sole purpose of the helmet was to protect them during unsteady cycling. The children had acquired their knowledge and conceptions from many different sources, mainly from the home and the pre-school. The observed traffic walks of the children passed smoothly, where the use of reflex vests and the groupings during the walks appeared to be ingrained and useful routines. The education of the pre-school and the home was carried through as practical training in the real traffic environment, preferably through walks, bus rides and cycling. In pre-school, the adult was a greater authority in the traffic situation than normally the case. Sometimes the pre-school worked with invisible delimitations as an educational tool with the purpose of protecting the children when in the traffic setting.