There has been a good effort made in Abu Dhabi for the last couple of years between government stakeholders to develop a road safety strategy, define rules and responsibilities, and gain a fully coordinated and integrated framework to deal with road safety. According to my point of view, the challenges that might be seen as a problem for the future development of Abu Dhabi can be the management and the usage of traffic safety technologies to reduce serious road traffic accidents. This study focused on the relationship between the use of traffic safety technologies and serious road traffic accidents on Abu Dhabi Highways. The motivation for this research is to implement correctly the traffic safety technologies in Abu Dhabi highways as a part of the need to adopt plans, programmes, and preventive measures to reduce or prevent the occurrence of traffic accidents in order to ensure the safety of individuals and property, in addition to preserving the security of the state and its human and economic components. The overall approach to this study is a mixed methodology, which combines quantitative and qualitative methods. A questionnaire is one method used in this regard, and is designed to be quantitative. In the quantitative method, comparing statistics of fatalities and injuries before and after installation of the speed cameras is used. As a result of this study and by making the connectivity between reviewing the results and findings of the literature review, identifying the questionnaire results, and exploring the before and after statistics led to findings which were used to develop a decision support framework that can be used to advise the regional safety strategy to be sustainable. The design framework was also validated through Abu Dhabi highways by a panel of experts, which was carried out using the focus group method, which was qualitative in nature. It is recommended from this research to invest much in traffic safety technologies, focus more on driver support systems and rapid response systems, improve driver behaviour as a priority in Abu Dhabi highways using traffic safety technologies, and integrate the compatibility of all of the above through an integrated system and specific performance indicators that are measured and followed up on an ongoing basis, and supported by geographic information systems (GIS).

This Master's thesis examines the possibility of implementing an intelligent transport system for monitoring road vehicles carrying dangerous goods through the territory of the Czech Republic, for the purpose of providing relevant information to emergency responders in the event of an accident involving such vehicles. The aim is to explore whether, and how, can radio-frequency identification technology be used in such a system. The scope of the research is not limited to technical aspects of the solution. Various options are considered in terms of capital costs, complexity of the required information system and impact on shippers and carriers from an economic and business process standpoint. The paper briefly describes the current legislation concerning the transport of dangerous goods, the existing processes and entities involved in transport and handling of traffic accidents. Following is a comparison of several possible implementations of the monitoring system.

With the advent of autonomous driving, concepts like road trains or platoons are becoming more popular. In these arrangements, vehicles travel at separations of only 5 to 10m between them. These short inter-vehicle distances allow compacting vehicle flows resulting in increased throughput on highways. In addition, there are also fuel/energy savings as the magnitude of aerodynamic resistance acting on vehicles is reduced. These benefits increase when reducing inter-vehicle separations to below 5m. However, it becomes extremely difficult to guarantee safety, especially, when braking in an emergency. The longitudinal and lateral control systems developed so far aim to achieve string stability in the cruise scenario, i.e., to prevent that small variations at the lead magnify towards the trail. Unfortunately, this has no relevance during emergency braking, since control systems incur saturation, i.e., the condition where computed output brake forces exceed those that can be applied by actuators. This is because all vehicles have to apply their maximum brake forces in order to minimize the stopping distance of the platoon and reach a complete standstill. As a result, emergency braking requires special attention and needs to be designed and verified independent of the cruise scenario. Braking in an emergency is mainly characterized by the problem of heterogeneous deceleration capabilities of vehicles, e.g., due to their type and/or loading conditions. As a result, a deceleration rate possible by one vehicle may not be achievable by its immediately leading or following vehicles. Not addressing this heterogeneity leads to inter-vehicle collisions. Moreover, transitions in the road profile increase the complexity of such brake maneuvers. Particularly, when there is a transition from a flat road to a steep downhill, an already saturated brake controller cannot counteract the effect of the downhill slope. Hence, its deceleration magnitude will be reduced, potentially leading to intra-platoon crashes that would otherwise not occur on a flat road. In this work, we first analyze the problem of emergency braking in platoons operating at inter-vehicle separations below 5m and under idealized conditions (i.e., flat road, instantaneous deceleration, etc.). For this case, we propose a cyber-physical approach based on exploiting space buffers that are present in the separations between vehicles, and compare it with straightforward schemes (such as Least Platoon Length and Least Stopping Distance) in terms of achieved aerodynamic benefits, overall platoon length, and stopping distance. We then consider realistic conditions (in particular, changing road profiles as mentioned before) and investigate how to design a brake-by-wire controller present at each vehicle that accounts for this. We further extend our proposed cyber-physical approach by adding cooperative behavior. In particular, if an individual vehicle is unable to track its assigned deceleration, it coordinates with all others to avoid inter-vehicle collisions, for which we propose a vehicle-to-vehicle (V2V) communication strategy. Finally, we present a detailed evaluation of the proposed cyber-physical approach based on high-fidelity vehicle models in Matlab/Simulink. Even though more work is needed towards a real-life implementation, our simulation results demonstrate benefits by the proposed approach and, especially, its feasibility.

Comprehensive information on traffic flow is essential for vehicular emission monitoring and traffic control. However, such information is not observable everywhere and anytime on the road because of high installation costs and malfunctions of stationary sensors. In order to compensate for stationary sensors’ weakness, this thesis analyses an approach for inferring traffic flows from mobile data provided by INRIX, a commercial crowd-sourced traffic dataset with wide spatial coverage and high quality. The idea is to develop Artificial Neural Network (ANN)-based models to automatically extract relations between traffic flow and INRIX measurements, e.g., speed and travel time, from historical data considering temporal and spatial dependencies. We conducted experiments using four weeks of data from INRIX and stationary sensors on two adjacent road segments on the E4 highway in Stockholm. Models are validated via traffic flow estimation based on one week of INRIX data. Compared with the traditional approach that fits the stationary flow-speed relationship based on the multi-regime model, the new approach greatly improves the estimation accuracy. Moreover, the results indicate that the new approach’s models have better resistance to the drift of input variables and can decrease the deterioration of estimation accuracy on the road segment without a stationary sensor. Hence, the new approach may be more appropriate for estimating traffic flows on the nearby road segments of a stationary sensor. The approach provides a highly automated means to build models adaptive to datasets and improves estimation and imputation accuracy. It can also easily integrate new data sources to improve the models. Therefore, it is very suitable to be applied to Intelligent Transport Systems (ITS) for traffic monitor and control in the context of the Internet of Things (IoT) and Big Data. / Information om trafikflödet är nödvändig för övervakning av fordonsutsläpp och trafikstyrning. Trafikflöden kan dock inte observeras överallt och när som helst på vägen på grund av höga installationskostnader och t.ex. funktionsstörningar hos stationära sensorer. För att kompensera för stationära sensorers svagheter analyseras i detta arbete ett tillvägagångssätt för att estimera trafikflöden från mobila data som tillhandahålls av INRIX. Detta kommersiella dataset innehåller restider som kommer från användare av bl.a. färdnavigatorer i fordon och som har en bred rumslig täckning och hög kvalitet. Idén är att utveckla modeller baserade på artificiellt neuronnät för att automatiskt extrahera samband mellan trafikflödesdata och restidsdata från INRIX-mätningarna baserat på historiska data och med hänsyn till tidsmässiga och rumsliga beroenden. Vi utförde experiment med fyra veckors data från INRIX och från stationära sensorer på två intilliggande vägsegment på E4:an i Stockholm. Modellerna valideras med hjälp av estimering av trafikflöde baserat på en veckas INRIX- data. Jämfört med det traditionella tillvägagångssättet som anpassar stationära samband mellan trafikflöde och hastighet baserat på fundamentaldiagram, förbättrar det nya tillvägagångssättet noggrannheten avsevärt. Dessutom visar resultaten att modellerna i den nya metoden bättre hanterar avvikelser i ingående variabler och kan öka noggrannheten på estimatet för vägsegmentet utan stationär sensor. Den nya metoden kan därför vara lämplig för att uppskatta trafikflöden på vägsegment närliggande en stationär sensor. Metodiken ger ett automatiserat sätt att bygga modeller som är anpassade till datamängderna och som förbättrar noggrannheten vid estimering av trafikflöden. Den kan också enkelt integrera nya datakällor. Metodiken är lämplig att tillämpa på tillämpningar inom intelligenta transportsystem för trafikövervakning och trafikstyrning.

The demand for road freight transport continues to grow with the growing economy, resulting in increased fossil fuel consumption and emissions. At the same time, the fossil fuel use needs to decrease substantially to counteract the ongoing global warming. One way to reduce fuel consumption is to utilize emerging intelligent transport system (ITS) technologies and introduce heavy-duty vehicle (HDV) platooning, i.e. HDVs driving with small inter-vehicle gaps enabled by the use of sensors and controllers. It is of importance for transport authorities and industries to investigate the effects of introducing HDV platooning. Previous studies have investigated the potential benefits, but the effects in real traffic, both for the platoons and for the surrounding vehicles, have barely been explored. To further utilize ITS and optimize the platoons, information about the traffic situation ahead can be used to optimize the vehicle trajectories for the platoons. Paper I presents a dynamic programming-based optimal speed control including information of the traffic situation ahead. The optimal control is applied to HDV platoons in a deceleration case and the potential fuel consumption reduction is evaluated by a microscopic traffic simulation study with HDV platoons driving in real traffic conditions. The effects for the surrounding traffic are also analysed. Paper II and Paper III present a simulation platform to assess the effects of HDV platooning in real traffic conditions. Through simulation studies, the potential fuel consumption reduction by adopting HDV platooning on a real highway stretch is evaluated, and the effects for the other vehicles in the network are investigated. / Efterfrågan på godstransporter på väg fortsätter att öka i takt med den växande ekonomin, vilket resulterar i ökad förbrukning av fossila bränslen och ökade utsläpp. Samtidigt behöver användandet av fossila bränslen minska för att motverka den pågående globala uppvärmningen. Ett sätt för att minska bränsleförbrukningen är att utnyttja den teknik kring intelligenta transportsystem som är under utveckling och introducera lastbilskonvojer, det vill säga lastbilar som använder sensorer och regulatorer för att kunna köra med korta avstånd mellan sig. För transportföretag och -myndigheter är det viktigt att undersöka effekterna av att införa lastbilskonvojkörning. Tidigare studier har undersökt de möjliga fördelarna, men effekterna vid körning i trafik, både för konvojerna och för omgivande fordon, är outforskade. För att ytterligare utnyttja intelligenta transportsystem och optimera konvojerna kan information om trafiksituationen längre fram på vägen användas för att optimera konvojernas körning. Artikel I presenterar en optimal hastighetsregulator baserad på dynamisk programmering och som inkluderar information om trafiksituationen längre fram. Den optimala regulatorn appliceras på lastbilskonvojer under ett inbromsningsscenario och den potentiella minskningen i bränsleförbrukning utvärderas genom en mikroskopisk trafiksimuleringsstudie där lastbilskonvojerna kör i verkliga trafikförhållanden. Effekterna för omgivande fordon är också analyserade.Artikel II och artikel III presenterar en simuleringsplattform för att utvärdera effekterna av lastbilskonvojkörning i verkliga trafikförhållanden. Genom simuleringsstudier analyseras den potentiella bränsleförbrukningsminskningen då lastbilskonvojer körs på en verklig motorvägssträcka och effekterna för de övriga fordonen på vägen undersöks. / <p>QC 20180516</p>

More than a million people die every year due to road traffic accidents globally where one in five serious or fatal accidents occurs during severe weather conditions. Sweden is in the lead of Vision Zero, with the aim of zero casualties due to road traffic, and every year new countries and organisations accept the challenge of saving lives. Early studies have shown that one way of decreasing casualties is to implement floating car data (FCD), which is data obtained from connected road vehicles. One example of such an implementation is to gather knowledge about the current state of the road network enabling targeted winter road maintenance. By implementing FCD for winter road maintenance, besides creating safer roads, savings will be made for the environment by reducing the use of fossil fuels and salt. Since the fleet of road vehicles is going towards being fully autonomous, the volumes of FCD will increase rapidly generating new possibilities for FCD usage. Recent research regarding FCD has mainly focused on traffic flow, speed and route optimisation, together with general methods for FCD mining creating intelligent transport systems. Studies have also been made to cover the gap between road weather information systems (RWIS) monitoring the road condition and thereby improving road weather forecasts. But there is a need for research regarding the implementation of FCD at a level of action, closer to the road users improving winter road maintenance. Presented in this thesis are results gathered in the project Digital Winter, a project initiated by the Swedish Traffic Administration, where FCD regarding tire-to-road friction has been procured for all public roads in Sweden. Results show promising numbers regarding coverage and reliability for implementation of FCD for winter road maintenance follow-up, managing that assigned levels of road friction are achieved. Examples are given for different areas in Sweden where harsh weather conditions are detected and statistics show coverage of FCD both at a daily and hourly level. Multiple suppliers of FCD have been participating in Digital Winter and the measurements presented, show a correlation between suppliers of FCD and methods that today are approved for winter road maintenance follow-up in Sweden. But also that the friction measured using FCD is closer to the true road friction experienced by road users.

Promoting cycling is a crucial solution to improve the livability of urban environments. A non-invasive way to promote cycling is to enhance the bike ride experience via Green Light Optimal Speed Advisory (bike-GLOSA). This work presents such a system for Hamburg, making bike-GLOSA practical in real-world urban environments and evaluating its impact on bike rides. GLOSA systems ingest data from traffic lights to predict their switching behavior and provide speed advisories to users. In the first challenge, we need to find whether the data is reliable, overseeing thousands of traffic lights throughout the city area. We develop a quality assurance framework and monitor the prediction quality over a longer period. Affected by data outages, we achieve a median prediction availability of 55% (IQR: 28%) and prediction quality of 86%. We identify concrete weak points, enhancing prediction stability by 11% to 66% (IQR: 17%) measured in 2024. Furthermore, based on four weeks of data for 18,009 traffic lights, we find that traffic adaptivity may be less problematic for traffic light prediction than previously envisioned. Afterward, we develop a novel method to match traffic lights along the user's trajectory. Instead of using the user's location or camera, our method matches traffic lights along a precalculated bike route geometry. However, errors and inaccuracies in bike routes challenge this approach, requiring an advanced model that employs spatial reasoning to find which associated traffic light turn geometries match the given route geometry. The final model achieves matching F1 scores of 92% and 86% validated on a separate dataset, requiring a median extra time of 1.4 seconds during bike route calculation. Building on these results, we focus on reducing bike routing errors and enhancing route alignment with actual bike paths. Our solution involves an authoritative bike routing dataset and cross-border routing to OpenStreetMap. Apart from a more consistent surface coverage, we find better alignment with actual cycling infrastructure, traffic lights, and user trajectories than with other routing providers. Enhanced alignment and 37% fewer routing errors lead to a 4.74% increase in traffic light matching F1 score. A route-based distance-to-signal estimation is proposed, showing a more stable distance estimation than the over-the-air distance from related work. We combine the developed components in a smartphone app and conduct an unsupervised long-term test throughout 2023 with Hamburg citizens. Survey responses suggest a twofold effect of the speed advisory: rolling out in anticipation of red and accelerating to catch green. These effects are also visible in the recorded data. Approaches with adherence to the speed advisory have 15.32% fewer stops but a 3.3% increase in energy expenditure to catch the green phase by cycling 2.92 km/h faster. Approaches without adherence have a 12.85% higher chance of stopping and a 3.39 km/h decrease in speed while saving 5.5% in energy and rolling out earlier. Combined, these cases cancel out each other, with a 0.74 km/h slower traffic light passing speed, 1.4% estimated energy savings, 0.73% increased stop rate, and 1.46 seconds increased waiting time when stopped. Based on the survey, users report a System Usability Scale of 73, with improvable reliability and coverage of speed advisories. Among many ways to improve our developed solution, users see enhanced informedness, reduced stops, and increased comfort as key benefits. We thoroughly analyze these findings and outline potential directions for future research.

O uso crescente de dispositivos móveis e o advento da Internet das Coisas têm demandado esforços para prover alternativas de comunicação sem fio. A utilização de sistemas óticos para a transmissão de dados apresenta-se como uma tecnologia promissora e complementar à comunicação por radiofrequência, especialmente devido aos desenvolvimentos consideráveis na tecnologia de iluminação por estado sólido e sua adoção em vários domínios. Os diodos de emissão de luz podem ser utilizados na promoção de comunicação por luz visível em ambientes internos e externos. Nos ambientes externos há inúmeras oportunidades a serem exploradas no que concerne aos Sistemas Inteligentes de Transporte, visto que os diodos de emissão de luz têm sido utilizados em luminárias públicas, semáforos e veículos. Esta pesquisa propôs o desenvolvimento e a avaliação de um sistema de comunicação por luz visível entre elementos da infraestrutura urbana e veículos, mais especificamente, luminárias públicas baseadas em diodos de emissão de luz e o modal de transporte público representado pelos ônibus que circulam em faixas exclusivas. A metodologia foi composta por simulação computacional e pela construção de um protótipo para auxiliar na validação das soluções propostas. O sistema complementar de comunicação sem fio por meio da luz proposto fornece pode fornecer subsídios à determinação do posicionamento preciso dos ônibus, suprindo as deficiências do sistema GPS em locais menos favoráveis à recepção de seus sinais em uma cidade. Essas informações auxiliam os usuários e os gestores do transporte público, atendendo alguns domínios de serviço em Sistemas Inteligentes de Transporte, de acordo com a norma ISO 14813. Os resultados obtidos nos testes com o protótipo, bem como, aqueles observados na simulação, comprovaram a viabilidade do sistema proposto, com o estabelecimento da comunicação entre luminária e ônibus, inclusive quando trafegando a 60 km/h. / The increasing use of mobile devices and the advent of the Internet of Things have called for efforts to provide alternatives for wireless communication. The use of optical systems for data transmission is a promising and complementary technology to radiofrequency communication, especially due to the considerable developments in solidstate lighting technology and its adoption in various domains. Light-emitting diodes can be used to promote visible light communication in indoor and outdoor environments. In outdoor environments there are numerous opportunities to be explored with regard to Intelligent Transport Systems, since light-emitting diodes have been used in public luminaires, traffic lights and vehicles. This research proposed the development and evaluation of a visible light communication system between elements of the urban infrastructure and vehicles, more specifically, public luminaires based on light-emitting diodes and the mode of public transport represented by buses that circulate in exclusive lanes. The methodology was composed by computational simulation and the construction of a prototype, to assist in the validation of the proposed solutions. The proposed complementary wireless communication system through light provides subsidies to determine the precise positioning of buses, supplying deficiencies of the GPS system in places less favorable to the reception of their signals in a city. This information helps the users and the managers of the public transport, attending some service domains in Intelligent Transport Systems, according to the ISO 14813 standard. The results obtained in the tests with the prototype, as well as those observed in the simulation, proved the feasibility of the proposed system, with the establishment of communication between luminaire and bus, even when traveling at 60 km/h.

Submitted by Fabricia Fialho Reginato (fabriciar) on 2015-06-29T23:38:32Z No. of bitstreams: 1 LuizHenriqueFeltes.pdf: 4322319 bytes, checksum: 98c3bdcf4789bd2a693e9eb290ea92c0 (MD5) / Made available in DSpace on 2015-06-29T23:38:32Z (GMT). No. of bitstreams: 1 LuizHenriqueFeltes.pdf: 4322319 bytes, checksum: 98c3bdcf4789bd2a693e9eb290ea92c0 (MD5) Previous issue date: 2013 / Nenhuma / O uso de computação móvel e ubíqua tem sido estimulado pela grande difusão dos dispositivos móveis, redes sem fio e sistemas de localização. Neste contexto, diversas aplicações estão surgindo em diferentes áreas, como educação, entretenimento, comércio e transportes. Esta dissertação propõe o MD-UTS, um modelo para o desenvolvimento de sistemas ubíquos de transporte. O modelo permite o gerenciamento de diferentes tipos de veículos em uma determinada região. Os veículos são gerenciados de acordo com seus perfis, criando um registro histórico de seu movimento. O modelo fornece informações através de serviços web que podem ser utilizadas por diferentes aplicações. A dissertação também descreve duas aplicações que usam o MD-UTS para gerenciar o transporte urbano. O MD-UTS foi integrado no simulador de transporte urbano chamado SUMO (Simulação da Mobilidade Urbana) para gerar dados sobre os veículos. Os resultados demonstram a viabilidade da proposta, facilitando a construção de aplicações direcionadas para o sistema de transporte. / The use of mobile and ubiquitous computing has been stimulated by the widespread diffusion of mobile devices, wireless networks and location systems. In this context, numerous applications are emerging in different areas such as education, entertainment, commerce and transport. This thesis proposes the MD-UTS, a model for development of ubiquitous transport systems. The model allows management of different types of vehicles in a given region. The vehicles are managed according to their profiles, making a historical record of their movement. The model provides information through web services that can be used by different applications. The thesis also describes two applications that use the MD-UTS to manage urban transport. The MD-UTS has been integrated into urban transport simulator called SUMO (Simulation of Urban Mobility) to generate data about the vehicles. The results demonstrate the feasibility of the proposed, facilitating the construction of applications directed to the transport system.

Améliorer la sécurité routière passe par une meilleure compréhension des causes d'accidents. Il est donc nécessaire de développer des observatoires discrets pour étudier la manière de conduire de tous les automobilistes. Une partie de cette analyse implique l'utilisation de capteurs mesurant les trajectoires des véhicules sur une portion de route. Deux capteurs innovants ont été crées pour pallier au manque de capteurs suffisamment précis pour ces travaux de recherche : le premier est un capteur à fibres optiques présentant une succession de réseaux de Bragg et le second, protégé par un brevet, est fondé sur une technologie résistive. Le premier repère la déformation locale de fibres optiques noyées à moins d'un centimètre sous la surface de la chaussée. Il utilise la variation de longueurs d'onde engendré par l'extension de la fibre à la zone de contact roue - sol. En utilisant un algorithme adéquat, il est insensible à la température. Le second est constitué de deux conducteurs dont un est résistif. Le poids du véhicule engendre un contact électrique entre les deux conducteurs, transformant la résistance électrique de l'ensemble. Les modèles développés, électrique ainsi que de variation thermique, permettent sa meilleure utilisation. Ils ont été soumis à une expérimentation sur une route départementale. Le capteur optique s'avère plus performant mais coûteux. Le deuxième n'est pas assez robuste mais présente des perspectives intéressantes. / This action stake is not technology for itself. It is a great help the development of new safety functions, e.g. the estimation of driver’s behaviour based uponthe vehicle’s trajectory. This trajectory is determined via two sensors we developed. This system must not disturb the driver and should therefore remain invisible to him. The first one is a fiber Bragg grating (FBG) sensor. It detects local strain due to the vehicle weight. The fiber is embedded in the road thanks to resin used in other traffic sensors. The vehicle location is spotted according to the variations of Bragg wavelengths. The fiber extension located under the ground - wheel contact zone changes the step of the Bragg grating. The second one is based upon two conductors. One of them has a grater electrical resistance. The vehicle’s weight creates a link between the two conductors. The resulting electrical resistance provides a lateral position estimation of the vehicle. Electrical and thermic models and simulation even increase the sensor reliability. A caveat is lodged. Both of them were tested on a secondary road. To put in a nutshell, the FBG sensor gives better results but is very expensive (sensors and interrogator too). The resistance sensor is not much raw nevertheless it has interesting perspectives.