229 research outputs found

    A new microsimulation model for the evaluation of traffic safety performances

    Get PDF
    Some papers have been recently presented (Cunto and Saccomanno 2007, Cunto and Saccomanno 2008, Saccomanno et al. 2008) on the potential of traffic microsimulation for the analysis of road safety. In particular, studies have confirmed that the reproduction by simulation of user behaviour under different flow and geometry conditions, can identify a potential incident hazard and allow to take appropriate countermeasures at specific points of the road network. The objective of this paper is to assess the validity of this approach; for this reason a microsimulation model and an automatic video detection system have been developed. The microscopic model allows the estimation of road safety performance through a series of indicators (Deceleration Rate to Avoid Crash, Time to Collision, Proportion of Stopping Distance), representing interactions in real time, between different pairs of vehicles belonging to the traffic stream. When these indicators take a certain critical value, a possible accident scenario is identified. The microscopic simulation model is used combined with a new video image traffic detection algorithm to calculate vehicle trajectories. Microscopic traffic flow parameters obtained by video detection are used to calibrate the microsimulation model, and the safety performance indicators obtained by the real vehicles trajectories can be compared with simulated scenarios where safety performance indicators are obtained on the simulated trajectories. Results indicate that the methodology can be useful in the estimation of safety performance indicators and in evaluating traffic control measures

    The Computer System Architecture of our first real-time real-world experiment of adaptive traffic signals with "connected" vehicles

    Get PDF
    Abstract Connected vehicles can transmit real-time information to traffic control management systems. Despite the recent technical advances of telecommunication networks and mobile computing there have been no real-time adaptive traffic signal control experiments with connected vehicles. Most of the research in this field has been carried out only with simulations. In this work we present the computer system that was adopted to regulate traffic signals in real-time with "smartphone-connected" vehicles as the only source of information. We introduce the description of the computer system architecture that was deployed in an experiment of a Floating Car Data (FCD)-based adaptive traffic signal in which a traffic signal has been regulated in real-time with 100% "smartphone-connected" vehicles. The description of the system based on commonly-used technologies could help others to develop and deploy new traffic signal management systems in new "connected" intersections

    A Review of the use of traffic simulation for the evaluation of traffic safety levels: can we use simulation to predict crashes?

    Get PDF
    Abstract This paper presents a literature review on the application of traffic simulation for the evaluation of traffic safety levels. The main aim is to identify, through the implementation of a multi-step methodology current research-trends, main gaps in the literature and possible future challenges. First, a bibliometric analysis is carried out to obtain a broad overview of the topic of interest. Subsequently, the most influential contributions are analysed in-depth, with specific attention to specific issues

    A review of traffic signal control methods and experiments based on Floating Car Data (FCD)

    Get PDF
    Abstract This paper intends to give a short review of the state of the art on the use of floating car data concerning the management of traffic flow at signalized intersections. New technologies such as connected and autonomous vehicles and Co-operative Intelligent Transportation Systems (C-ITS) are going to change the future of traffic control and management. Traffic signal control systems can be reorganized by using Floating Car Data (FCD), yet the concept of floating car data (FCD) has been mainly studied to gain traffic information and/or signal information. Only recent works have been focalizing on the potential application of FCD for traffic signal real-time control. This paper aims to evidence the most important concepts that can be extracted from the literature on this important topic

    The use of a Blockchain-based System in Traffic Operations to promote Cooperation among Connected Vehicles

    Get PDF
    Abstract This paper intends to present some ideas for the implementation of cooperative ITS systems based on the Blockchain Technology (BT) concept. Blockchain technology has been recently introduced and, in this paper, we discuss a system that is based on a dedicated blockchain, able to involve both drivers and city administrations in the adoption of promising and innovative technologies that will create cooperation among connected vehicles. The proposed blockchain-based system can allow city administrators to reward drivers when they are willing to share travel data. The system manages in a special way the creation of new coins which are assigned to drivers and institutions participating actively in the system. Moreover, the system allows keeping a complete track of all transactions and interactions between drivers and city management on a completely open and shared platform. The main idea is to combine connected vehicles with BT to promote Cooperative ITS use and a better use of infrastructures

    mobile for emergencies m4em a cooperative software tool for emergency management operations

    Get PDF
    Abstract In serious emergencies, as in the case of floods and extreme weather conditions, where a substantial number of people are involved and over vast areas which may also involve different provinces, currently civil protection planning carries on emergency management operations within rigid schemes. A procedure that would be capable of handling events acquiring data continuously and developing real time solutions in a highly flexible manner has not yet been proposed. This research focuses on how the systematization of information systems and communication processes can improve the management of emergencies caused by extreme weather and climate events. The objectives of improved service, levels of safety and sustainability of the intervention in emergencies would be obtained through a centralized decision support system. The system and tools that are presented in this paper aim to respond to emergency issues dynamically responding to the dynamics of the events by taking advantage of an information system capable of sharing data, notifications, service orders, appeals for help, information on the status of the transport network and any other information. The system would provide decision support by acquiring information from smartphones and other nomadic devices; it would so provide exchange of information in real time on one or more virtual platforms among stakeholders and between them and the citizens. Substantially, the system is based on smartphone applications coupled with a central management emergency Decision Support System specifically built to make best use of the possibilities offered by the latest telematics systems and cooperative web and phone-based tools

    the use of smartphones to assess the feasibility of a cooperative intelligent transportation safety system based on surrogate measures of safety

    Get PDF
    Abstract The future of road transportation is going to be shaped by connectivity and autonomous driving. Connected and autonomous vehicles are expected to increase safety and reduce traffic congestion. Once all the vehicles are connected and geo-localized there might still be a need to integrate a different level of autonomous vehicles on the road: from the human driven vehicle to the fully autonomous vehicle. While surrogate safety measures have been extensively considered to estimate the risk of accidents due to improper driving, there has been no attempt to use them to help drivers achieve a better driving style. This paper presents an experimentation on the idea to warn drivers when they are driving in such a way (owing to their interactions with other vehicles) that could potentially lead to an accident. In the proposed system the driver is warned of the risk of collision by the combined use of localization (GPS) gathered information and the application of road safety indicators such as Deceleration Rate to Avoid a Crash, Time To Collision and others. The experimentation involving car-following vehicles showed the feasibility, with existing technologies, of using surrogate measures of safety to assist the driver in keeping a better driving trajectory. Once connected vehicles are introduced on the market, the presented results can be a base to develop commercial smartphone applications that will allow users of "not connected" old vehicles to also take advantage of real time driving assistance for a safer use of the road

    Co-operative ITS: ESD a smartphone based system for sustainability and transportation safety

    Get PDF
    Abstract Co-operative Intelligent Transportation Systems (C-ITS) are emerging rapidly due to recent development in Global Navigation Satellite System GNSS systems and mobile internet. The main goal of these systems is to improve traffic conditions and safety level on the road networks. With the rapid growth of smartphone technologies and mobile internet, C-ITS based on smartphone may contribute increasingly in vehicle data collection and in traffic safety and sustainability issues. This paper, extending previous research results, explores the possibilities of using smartphone applications coupled with a central server GIS (Geographic Information System) web system to contribute to traffic safety and to reduce fuel consumption. The idea of a co-operative system in which GPS (Global Positioning System) enabled smartphones are capable to acquire individual vehicle's kinematics is extended to take into account both safety and fuel consumption issues. Information in the system is shared on a web server for promoting more sustainable and safe driving styles. The co-operative system allows drivers to examine information about their individual driving style and consumptions allowing a better use of the road. Road operators can use the system to find critical points on the network and to promote traffic safety

    Unbiased metabolomic investigation of Alzheimer's disease brain points to dysregulation of mitochondrial aspartate metabolism

    Get PDF
    Alzheimer's disease (AD) is the most common cause of adult dementia. Yet the complete set of molecular changes accompanying this inexorable, neurodegenerative disease remains elusive. Here we adopted an unbiased lipidomics and metabolomics approach to surveying frozen frontal cortex samples from clinically characterized AD patients (n = 21) and age-matched controls (n = 19), revealing marked molecular differences between them. Then, by means of metabolomic pathway analysis, we incorporated the novel molecular information into the known biochemical pathways and compared it with the results of a metabolomics meta-analysis of previously published AD research. We found six metabolic pathways of the central metabolism as well as glycerophospholipid metabolism predominantly altered in AD brains. Using targeted metabolomics approaches and MS imaging, we confirmed a marked dysregulation of mitochondrial aspartate metabolism. The altered metabolic pathways were further integrated with clinical data, showing various degrees of correlation with parameters of dementia and AD pathology. Our study highlights specific, altered biochemical pathways in the brains of individuals with AD compared with those of control subjects, emphasizing dysregulation of mitochondrial aspartate metabolism and supporting future venues of investigation
    • …
    corecore