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The use of modeling and simulation aids in deriving many decisions related to transportation planning and traffic operations. Representing the real systems via simulation allows exploring system behavior in an articulated way, which is often impossible in the real world. In this paper, a simulation-based framework is presented to evaluate the impact of congestion charging on daily activity plans of the individuals. Personal decision to accept the congestion charges is evaluated by comparing the value of time with congestion charge. Value of time varies throughout the day depending upon the time pressure at any moment exerted by preceding and succeeding activities. Time pressure during an activity increases if available time for that activity is insufficient to attain the perceived utility. Daily activities in the schedules are modeled using bell-shaped marginal utility that results in sigmoid utility. A model is presented which derives the activity-specific parameters of the marginal utility function for the specific individual. To examine value of time of each person, the congestion charging is applied where personal willingness-to-pay is determined by comparing the ratios of cost to utility for original and adapted schedules. A large-scaled microsimulation of the modeled framework is used to simulate the whole population, which is created by FEATHERS, an operational activity-based model for Flanders, Belgium. The results of the simulation show that the number of individuals who avoid the congestion charges by adapting their schedules is almost three times the number of those who agree to pay it. The proposed framework can be useful to evaluate the tradeoff between value of time and costs where flexibility in selection of time defines the variability in cost. [ABSTRACT FROM AUTHOR]

Path computation in a network is dependent on the network's processes and resource usage pattern. While distributed traffic control methods improve the scalability of a system, their topology and link state conditions may influence the sub-optimal path computation. Herein, we present Pathfinder, an application-aware distributed path computation model. The proposed model framework can improve path computation functions through software-defined network controls. In the paper, we first analyse the key issues in distributed path computation functions and then present Pathfinder's system architecture, followed by its design principles and orchestration environment. Furthermore, we evaluate our system's performance by comparing it with FreeFlow and Prune-Dijk techniques. Our results demonstrate that Pathfinder outperforms these two techniques and delivers significant improvement in the system's resource utilisation behaviour. [ABSTRACT FROM AUTHOR]

Purpose: Freight vehicle parking facilities at large urban freight traffic generators, such as urban retail malls, are often characterized by a high volume of vehicle arrivals and a poor parking supply infrastructure. Recurrent congestion of freight parking facilities generates environmental (e.g. pollution), economic (e.g. delays in deliveries) and social (e.g. traffic) negative externalities. Solutions aimed at either improving or better managing the existing parking infrastructure rely heavily on data and data-driven models to predict their impact and guide their implementation. In the current work, we provide a quantitative study of the parking supply and freight vehicle drivers' parking behaviour at urban retail malls. Methods: We use as case studies two typical urban retail malls located in Singapore, and collect detailed data on freight vehicles delivering or picking up goods at these malls. Insights from this data collection effort are relayed as data stories. We first describe the parking facility at a mall as a queueing system, where freight vehicles are the agents and their decisions are the parking location choice and the parking duration. Results: Using the data collected, we analyse (i) the arrival rates of vehicles at the observed malls, (ii) the empirical distribution of parking durations at the loading bays, (iii) the factors that influence the parking duration, (iv) the empirical distribution of waiting times spent by freight vehicle queueing to access the loading bay, and (v) the driver parking location choices and how this choice is influenced by system congestion. Conclusions: This characterisation of freight driver behaviour and parking facility system performance enables one to understand current challenges, and begin to explore the feasibility of freight parking and loading bay management solutions. [ABSTRACT FROM AUTHOR]

Introduction: The planning of transport infrastructures in France has been marked by three major developments: the European reform concerning the opening of rail transport to competition, the privatisation of semi-public motorway concession-holding companies, and the use of public-private partnership contracts. This article proposes examining the following research question: how to plan a series of infrastructure projects within an uncertain context? The methodology: (i) analyses whether the objectives (traffic, travel time, safety, cost, socio-economic profitability, financial profitability) of the 12 motorway and HSL projects built since the 1990s have been attained with the new planning procedure (such as risk management methods, financial risk assessment, impact assessment, public consultation) (ii) compares the additional costs and delays for three HSL projects according to their type of financing and whether or not they have used these planning procedures. Results: The analysis shows that traffic levels are lower than forecasts for 8 projects. The cost is greater than the forecasts for all infrastructures. The socio-economic profitability and the financial profitability are also lower than forecasts for approximately two-thirds of the projects. Conclusion: The social, political, institutional and environmental risks are generally well identified and treated by the client, no matter whether public or private.. The risk of additional cost is less well covered. The traffic risk remains a topical issue. Anticipating risks is liable to produce other risks, such as overcosts or opposition. It seems necessary to deepen the traffic forecast studies and to develop the multi criteria analysis method that can take account of the different points of view from the consultation. [ABSTRACT FROM AUTHOR]

Purpose: Road traffic incidents cause delay, affect public safety and the environment. The CEDR PRIMA project aims to extend practical guidance for traffic managers in pro-active Traffic Incident Management (TIM) techniques to reduce the impacts and associated costs of incidents. Methods: The paper describes modelling methods used in the project for assessing the effect of different management techniques on incident duration and travel delay under various scenarios, including collision, adverse weather, heavy vehicle breakdown and other obstruction, assuming various management strategies and generic impacts of novel technologies. Macroscopic simulations of 178 variations of 13 basic scenarios have been performed using a flexible and computationally efficient macroscopic queue model, results being verified by simulation using a velocity-based Cell Transmission Model (CTM-v). Results: The results of the two modelling methods are broadly consistent. While delays estimated by the two methods can differ by up to 20%, this is small compared to the factor of 30 range of modelled delays caused by incidents, depending on their nature and circumstances, and is not sufficient to affect general conclusions. Under the peak traffic conditions assumed, the most important factor affecting delay is whether running lanes can be kept open, but quick clearance of carriageway is not always feasible. Conclusions: Comparison of two very different modelling methods confirms their consistency within the context of highly scenario-dependent results, giving confidence in the results. Future research and data needs include further validation of the models, potential application to traffic flow and conflict prediction and incident prevention, and more complete and consistent recording of incident timelines and impacts. [ABSTRACT FROM AUTHOR]

In the field of self-driving technology, the stability and comfort of the intelligent vehicle are the focus of attention. The paper applies cognitive psychology theory to the research of driving behavior and analyzes the behavior mechanism about the driver's operation. Through applying the theory of hierarchical analysis, we take the safety and comfort of intelligent vehicle as the breakthrough point. And then we took the data of human drivers' perception behavior as the training set and did regression analysis using the method of regression analysis of machine learning according to the charts of the vehicle speed and the visual field, the vehicle speed and the gaze point as well as the vehicle speed and the dynamic vision. At last we established linear and nonlinear regression models (including the logarithmic model) for the training set. The change in thinking is the first novelty of this paper. Last but not least important, we verified the accuracy of the model through the comparison of different regression analysis. Eventually, it turned out that using logarithmic relationship to express the relationship between the vehicle speed and the visual field, the vehicle speed and the gaze point as well as the vehicle speed and the dynamic vision is better than other models. In the aspect of application, we adopted the technology of multi-sensor fusion and transformed the acquired data from radar, navigation and image to log-polar coordinates, which makes us greatly simplify information when dealing with massive data problems from different sensors. This approach can not only reduce the complexity of the server's processing but also drives the development of intelligent vehicle in information computing. We also make this model applied in the intelligent driver's cognitive interactive debugging program, which can better explain and understand the intelligent driving behavior and improved the safety of intelligent vehicle to some extent. [ABSTRACT FROM AUTHOR]

Select link analysis provides information of where traffic comes from and goes to at selected links. This disaggregate information has wide applications in practice. The state-of-the-art planning software packages often adopt the user equilibrium (UE) model for select link analysis. However, empirical studies have repeatedly revealed that the stochastic user equilibrium model more accurately predicts observed mean and variance of choices than the UE model. This paper proposes an alternative select link analysis method by making use of the recently developed logit-weibit hybrid model, to alleviate the drawbacks of both logit and weibit models while keeping a closed-form route choice probability expression. To enhance the applicability in large-scale networks, Bell's stochastic loading method originally developed for logit model is adapted to the hybrid model. The features of the proposed method are twofold: (1) unique O-D-specific link flow pattern and more plausible behavioral realism attributed to the hybrid route choice model and (2) applicability in large-scale networks due to the link-based stochastic loading method. An illustrative network example and a case study in a large-scale network are conducted to demonstrate the efficiency and effectiveness of the proposed select link analysis method as well as applications of O-D-specific link flow information. A visualization method is also proposed to enhance the understanding of O-D-specific link flow originally in the form of a matrix. [ABSTRACT FROM AUTHOR]

A comprehensive project evaluation and decision-making method considering multiple objectives, stakeholders, and attributes of proposed traffic treatments is inherently complicated. Although individual techniques in evaluating operations, safety, economic, and stakeholder objectives are available, a practical method that integrates all these risk factors and their uncertainties into a multi-attribute decision-making tool is absent. A three-level project decision-making process was developed to model and assess multiple-attribute risk in a proposed traffic treatment from the perspective of multiple stakeholders. The direct benefits from reducing delay and safety risk (basic objectives of traffic treatments) are computed in Level 1 with established methods. Feasibility and performance analysis in Level 2 examine site-specific constraints and conduct detailed performance analysis using advanced analysis tools. In Level 3, this paper introduces an innovative and integrated multiple attributes evaluation process under fuzziness and uncertainty (MAFU) process for evaluation and decision-making. The MAFU is a comprehensive and systematic assessment and decision-making procedure that can assess the magnitudes of project performance and to integrate conflicting interests and trade-offs among stakeholders. A case study illustrates the application of MAFU for the selection of a traffic alternative involving several evaluation attributes and stakeholders. Results show that the MAFU produced the smallest variance for each alternative. With traditional cost-benefit evaluation methods, the uncertainty associated with performance of a traffic project in terms of operation, safety, environmental impacts, etc., is unrestricted and cumulative. Therefore, a reliable multi-attribute evaluation of complex traffic projects should not be made with conventional cost-benefit analysis alone but with a process like MAFU. [ABSTRACT FROM AUTHOR]

High levels of pollution and congestion in urban centres are an increasing concern for local councils in the UK. Heavy goods vehicles delivering urban freight to city centres are a leading cause of this problem. This paper discusses the concept of using light rail networks to deliver freight to city centres from surrounding businesses. Specifically, various innovative designs are considered for the interior of the metro carriage and developed into visual models using Autodesk Inventor software. A full evaluation of all the designs developed is completed, resulting in a proposed design for consideration. The conclusion reached is that the proposed interior design is viable and coincides with the future metro fleet designs and concepts. [ABSTRACT FROM AUTHOR]

Lysosomal distribution is linked to the role of lysosomes in many cellular functions, including autophagosome degradation, cholesterol homeostasis, antigen presentation, and cell invasion. Alterations in lysosomal positioning contribute to different human pathologies, such as cancer, neurodegeneration, and lysosomal storage diseases. Here we report the identification of a novel mechanism of lysosomal trafficking regulation. We found that the lysosomal transmembrane protein TMEM55B recruits JIP4 to the lysosomal surface, inducing dyneindependent transport of lysosomes toward the microtubules minus-end. TMEM55B overexpression causes lysosomes to collapse into the cell center, whereas depletion of either TMEM55B or JIP4 results in dispersion toward the cell periphery. TMEM55B levels are transcriptionally upregulated following TFEB and TFE3 activation by starvation or cholesterolinduced lysosomal stress. TMEM55B or JIP4 depletion abolishes starvation-induced retrograde lysosomal transport and prevents autophagosome-lysosome fusion. Overall our data suggest that the TFEB/TMEM55B/JIP4 pathway coordinates lysosome movement in response to a variety of stress conditions. [ABSTRACT FROM AUTHOR]

Software Defined Network (SDN) is a new network technology which allows network providers to afford predefined Quality of Service (QoS) for video streaming applications. Network administrators can develop desired traffic engineering techniques over SDN and support Quality of Experience (QoE) and QoS for their customers. One of the most important issues in traffic engineering is to find favorable links for routing between source and destination. The fitness of each link in the network depends on the end users QoE and the applications they are used. In this paper to achieve optimal routes, the fitness of each link is determined by type-2 fuzzy sets. Then, an adaptive traffic engineering method is proposed to find the best routes between source cameras and monitoring center in a video surveillance system. The proposed method is based on Constraint Shortest Path (CSP) problem and calculates minimum cost path which satisfies delay constraint. Due to NP-completeness of the CSP problems, LARAC algorithm is used to solve it. To the best of our knowledge, this is the first proposed traffic engineering technique which is based on type-2 fuzzy set for video streaming applications over SDN. The contribution of the proposed method regarding to the related works, is to apply type-2 and type-1 fuzzy logic for calculating the costs of network links based on QoE for providing QoS in a video surveillance system. In addition, this paper models the provisioning of QoS in a real scenario and emulates them in a network emulator. Many comparisons carried out between the proposed method and other well-known methods to show the effectiveness of the proposed method in terms of packet loss, delay and PSNR. [ABSTRACT FROM AUTHOR]

The mechanical performance of epoxy asphalt concrete has been well reported in existing studies. This study investigated the surface characteristics of asphalt concrete, including the permeability, friction coefficient, moisture damage resistance and surface texture. The permeability test, dynamic friction test, Cantabro test, Hamburg test and laser texture scanning test were carried out for such investigations. Test results show that the permeability of the epoxy asphalt concrete was very low, which is desirable for protecting the steel deck. The friction coefficient can satisfy the requirement for steel deck bridge according to the Pendulum Number. However, it was found that the skid resistance could be a concern when the vehicle speed is higher than a certain level according to the dynamic friction test. The results suggested to control the traffic speed when epoxy asphalt concrete is applied as steel bridge pavement. In terms of the raveling and stripping, it was found that the epoxy asphalt mixture has an excellent anti-stripping performance based on the Cantabro test and Hamburg wheel tracking test results. The yield point was not reached after 20,000 loading cycles at 60 °C in the immersed Hamburg wheel tracking test. The mean profile depth of the epoxy asphalt concrete is 0.305 mm, much lower than conventional asphalt concrete indicating a very fine surface texture. [ABSTRACT FROM AUTHOR]

The objective of this research is to investigate the pavement response of road-bridge transition section without slab under impact load caused by vehicle bumping. The three-dimensional (3D) finite element models (FEM) of road-bridge transition section without slab were developed to simulate the response under impact load. The influence of different parameters (damping ratio, step height, vehicle speed as well as axle load) on the pavement response was investigated. Results indicated that an obvious increase of pavement response was observed with the step height and axle load rising. On the contrary, the rise of vehicle speed and damping ratio led to the decrease of pavement response. In addition, the pavement under impact load exhibited larger response as compared to under static load. Therefore, the phenomenon that static load was considered only in the traditional pavement structure is defective. Finally, the correction coefficients of design index for highway asphalt pavement were proposed to consider the influence of impact load. [ABSTRACT FROM AUTHOR]

In China, the research on asphalt pavement deterioration was hindered by a lack of comprehensive investigations on field data collection of pavement performance within its service life. The problem of traditional methods that yield inadequate data can be addressed using a combination of the Pavement Mechanistic-Empirical (PME) system and matter-element analysis (MEA). Measured data for the rutting of a road section in the Shaanxi province was employed as the validation data in this study. The input parameter for PME was localized, and a decay model based on the predicted results of PME was established by the MEA method. The results from PME indicate that the predicted results of rutting show a ''lagging" characteristic when compared with the measured data. Some optimization measures are employed to process the predicted results of PME so as to better fit the measured data. The predicted data for rutting resistance can be considered essential data for the MEA method to investigate the decay tendency of the rutting of asphalt pavement in its design life. A case study indicates that the rutting resistance of asphalt pavement will deteriorate from excellent to good, good to medium, medium to inferior, and inferior to bad in 13.8 months, 32.5 months, 43.8 months, and 55.2 months, respectively. The combination of PME and MEA proves to be appropriate to evaluate rutting potential in project level pavements. Follow-up research can be carried out on the developing trend of pavement damage, so as to better determine the maintenance time for a chosen road section. [ABSTRACT FROM AUTHOR]

The paper evaluates the contents of total forms of selected heavy metals (Zn, Cu, Ni and Pb) as well as the activity of catalase (CAT), dehydrogenases (DEH), alkaline phosphatase (AlP) and acid phosphatase (AcP) in mineral surface horizons of forest soils exposed to the effect of road traffic pollutions. The sampling locations ( n = 24) were determined in the area covered by the Szubin Forest along the exit road from Bydgoszcz to Poznań (provincial road no. 223). Soil was sampled 25 m away from the traffic lane, from two depths, 5-20 cm (humus horizons) and 20-50 cm (eluvial horizons). The contents of the heavy metals analysed were in the order of Pb > Zn > Cu > Ni. Despite intensive road traffic, with the Integrated Pollution Index ( IPI) calculated, there was found a low pollution with nickel, average with zinc and copper and high with lead only. However, under the Regulation of the Minister of Environment, heavy metal values recorded allow for classifying the soils analysed as soils unpolluted with those metals. In the soil samples analysed, there were found significant positive dependencies between the content of clay fraction and zinc ( r = 0.455; P < 0.05) and copper ( r = 0.430; P < 0.05). With the enzyme activity results, values of the soil resistance index ( RS) were calculated. The enzymes analysed were classified in the following decreasing order in terms of their resistance to traffic pollution: catalase > acid phosphatase > alkaline phosphatase > dehydrogenases (humus horizons) and catalase > dehydrogenases > alkaline phosphatase > acid phosphatase (eluvial horizons). Organic carbon showed a significant positive correlation with the activities of alkaline ( r = 0.668; P < 0.05) and acid phosphatase ( r = 0.668; P < 0.05) however not with catalase and dehydrogenases. [ABSTRACT FROM AUTHOR]

Smart cities involve the provision of advanced services for road traffic users. Vehicular ad hoc networks (VANETs) are a promising communication technology in this regard. Preservation of privacy is crucial in these services to foster their acceptance. Previous approaches have mainly focused on PKI-based or ID-based cryptography. However, these works have not fully addressed the minimum information disclosure principle. Thus, questions such as how to prove that a driver is a neighbour of a given zone, without actually disclosing his identity or real address, remain unaddressed. A set of techniques, referred to as Attribute-Based Credentials (ABCs), have been proposed to address this need in traditional computation scenarios. In this paper, we explore the use of ABCs in the vehicular context. For this purpose, we focus on a set of use cases from European Telecommunications Standards Institute (ETSI) Basic Set of Applications, specially appropriate for the early development of smart cities. We assess which ABC techniques are suitable for this scenario, focusing on three representative ones-Idemix, U-Prove and VANET-updated Persiano systems. Our experimental results show that they are feasible in VANETs considering state-of-the-art technologies, and that Idemix is the most promising technique for most of the considered use cases. [ABSTRACT FROM AUTHOR]

This study aims at demonstrating how cycle tourism could activate a regeneration of small and medium sized stations in inland areas, able to involve also territorial and urban areas hosting these stations. Starting point of this research is the issue of the small and medium sized Italian stations, mostly unused even if they are still active as rail service. Since control of trains' traffic is organized only in bigger railway yards, small stations are gradually becoming empty containers: ghost stations, without any railway personnel. Thanks to the potentiality of the cycle tourism, riding slow through landscapes, it becomes possible to valorize and safeguard this heritage, not only exploiting its potentiality as shift-node between train and bike, but also imaging a systemic strategy triggering urban, territorial and social reactivation. Main challenge was to experiment how another model of mobility, the cycle tourism, able to promote a territorial project preferring to pass slowly through the inland areas, avoided by the fast infrastructural lines, could contribute in such regeneration process. In order to validate this intuition, it was carried out a project of four stations in proximity of the cycle tourist path VENTO, along the Po River. These stations were transformed in 'green mobility hubs', where shifting from train to bicycle and vice versa. This becomes the occasion to imagining new functions hosted in empty spaces of stations (both internal and external): they will provide cycle tourists with territorial info and specific services, such as repair areas and bikes and baggage safekeeping and both tourists and local inhabitants with social activities in order to bring them to live again station's area. These functions want to generate an expectation, both in tourists and local people, to rediscover the territory around: in this way stations reassume their role of urban and territorial gates. [ABSTRACT FROM AUTHOR]

Traffic congestion is a major mobility problem, which generates enormous economic resources and causes serious problems for the most dense of cities. Intelligent transportation systems based on vehicular ad-doc network (VANET) communications will improve many services, expressively, related to transport, security, reliability, management and including the assistance in the reduction of traffic congestion. In this context, we propose an intelligent system based, firstly, on a new clustering technique to control and maintain the stability of routes during inter-vehicular communications, and secondly, a bio-inspired systematically conducting mobility measurement of agent, intervening in cases of traffic congestion, in order to find new routes to those offered by the global positioning system. Obviously, by providing an appropriate route selection process, such routing concept could be helpful in exchanging control messages to inform the nearest medics willing to give first aid and routing of another alert to the nearest ambulance. Thus, in order to deal with these sophisticated optimization techniques, we evaluate in this article means of simulation experiments. According to that, we have anticipated particular incidents suitable to estimate the pertinence of the proposed system. The analysis and implementation in VANET will be based on three simulators, especially, SUMO, MOVE and NS2. The results prove the effectiveness of the approach by reducing fuel consumption and $$\hbox {CO}_{2}$$ emissions along with the rest of pollutant emissions in the case of an incident. [ABSTRACT FROM AUTHOR]

The wireless sensor networks are used in tracking and monitoring objects. Owing to the wireless nature of communication, the adversary eavesdrops and back traces the origin of the message. The detection of source location information threatens the source node as well as the monitored object and reduces the functionality of the network. Existing approaches hide the location of the source node with fake packets, which is not a cost effective solution for resource-limited sensor networks. Therefore in this work, virtual source-α approach prevents the adversaries from tracing the source location. The virtual source-α approach is based on virtual source based approach which efficiently handles the realistic global eavesdropper. The performance of this approach is compared with the periodic collection and the source simulation approach with respect to the network and source location privacy. The simulation results show that virtual source-α approach performs better than the existing approaches. [ABSTRACT FROM AUTHOR]

The recent preparation of the Operation and Maintenance (O&M) Manual for Palestinian municipalities is an important step to guide them towards preparing and implementing their O&M priority-based plans, considering scare resources. During the course of preparation of the Manual, the proposed procedures were applied at ten pilot municipalities. This study aims to explore the outcome of the implementation of the 2014 O&M road maintenance plans at these municipalities. To achieve this, analysis of the outcome of a questionnaire designed to collect relevant information from these municipalities was conducted. The results show that seven of the targeted municipalities used the prioritization criteria proposed in the O&M Manual. Despite that the remaining municipalities had the liberty to slightly change the relative weight of the indicators, sensitivity analysis was conducted and indicated robustness of the indicators. The average percentage of roads' lengths of the actually maintained to the planned was 35%, suggesting that the plans were ambitious and need to be more rational. Most of the allocated funds for road maintenance came from the municipalities own budgets, indicating need to have more financing by the government to ensure the integrity of the municipal road infrastructure assets. The results also indicated that 95% of the maintenance works were executed through external contracts, and that the municipalities need to be supported and equipped to conduct the basic road maintenance works. [ABSTRACT FROM AUTHOR]

Uneven workload distributions in teams can lead to suboptimal team performance. This paper therefore describes the design of a virtual assistant that supports workload harmonization in teams by measuring workload, informing team members about their own and other team members' workload, and supporting team members in the redistribution of workload. The virtual assistant was developed in the context of train traffic control according to the situated Cognitive Engineering (sCE) methodology, which was extended to allow for a value sensitive design process. More specifically, the values 'insight,' 'helping others' and 'privacy' were explicitly accounted for throughout the design of the virtual assistant. A prototype of the virtual assistant was evaluated positively in a focus group. Thereby, the contribution of the paper is twofold. First, an improvement in a human-centered development methodology-sCE with values-is described and its use is demonstrated in an actual design case. Second, a novel, positively evaluated solution for workload harmonization in teams is presented. [ABSTRACT FROM AUTHOR]

There has been an increase in the amount and complexity of traffic on Dutch inland waterways. Traffic management shifted from local traffic control to corridor traffic management. Due to these changes, operators in nautical traffic management centers experience difficulty to gain and maintain sufficient situation awareness. In our previous research, three groups of deficiencies of current situation awareness support have been identified. To overcome these deficiencies, a theoretical framework for information engineering user interface concepts was developed and used for designing three interface concepts. A coherent, an integrated and a context-dependent adaptable user interface were designed and implemented as testable prototypes. To support the process of information engineering, we combined user-centered design techniques with the formalism of set theory, directed graphs and semantic networks. From a methodological point of view, these proved to be useful both in conceptualization and implementation of the concepts. The usability of these concepts was tested in a simulator environment. The results show that the implemented prototypes represent an important improvement compared to the traditional interface solutions currently used by nautical traffic management operators. However, it was recognized that the coherent user interface implementation still suffered from a number of deficiencies. The context-dependent adaptable user interface was evaluated most positively. [ABSTRACT FROM AUTHOR]

The transportation problem (TP) is an important supply chain optimization problem in the traffic engineering. This paper maximizes the total profit over a three-tiered distribution system consisting of plants, distribution centers (DCs) and customers. Plants produce multiple products that are shipped to DCs. If a DC is used, then a fixed cost (FC) is charged. The customers are supplied by a single DC. To characterize the uncertainty in the practical decision environment, this paper considers the unit cost of TP, FC, the supply capacities and demands as Gaussian type-2 fuzzy variables. To give a modeling framework for optimization problems with multifold uncertainty, different reduction methods were proposed to transform a Gaussian type-2 fuzzy variable into a type-1 fuzzy variable by mean reduction method and CV reduction method. Then, the TP was reformulated as a chance-constrained programming model enlightened by the credibility optimization methods. The deterministic models are then solved using two different soft computing techniques-generalized reduced gradient and modified particle swarm optimization, where the position of each particle is adjusted according to its own experience and that of its neighbors. The numerical experiments illustrated the application and effectiveness of the proposed approaches. [ABSTRACT FROM AUTHOR]

Development of speed model is a challenging task particularly under mixed traffic condition where the traffic composition plays a significant role in determining the individual vehicle speed. Estimation of passenger car equivalent (PCE) which is essential in converting the mixed traffic volume into its equivalent homogeneous also requires the speed information of individual vehicle categories at varying traffic conditions on the road. The present research was carried out to model the individual vehicle speed and to study the effects of traffic volume and its composition on individual speed and PCE in the context of urban mixed traffic. Traffic data on classified traffic volume and speed information were collected at six-lane divided arterial mid-block road sections in New Delhi, India. The methodology of artificial neural network was adopted to develop a volume-based speed prediction model for individual vehicle category. Validation results showed a great deal of agreement between the predicted and the observed speeds. Then, the sensitivity analysis was performed utilizing the model developed in order to examine the effects of traffic volume and its composition on individual speed and corresponding PCE. [ABSTRACT FROM AUTHOR]

Various initiatives, strategies and programmes have been taken by the Government of Malaysia to resolve issues pertaining to road traffic deaths. Nevertheless, the implementation of the programmes outlined in Malaysian Road Safety Plan 2006 needs to be enhanced in order to achieve the set targets. In this regard, it is imperative for all parties concerning road safety to determine the factors that significantly contribute to road traffic deaths. According to the Ministry of Works, Malaysia, the blackspot treatment programme (which is centred on the elimination of road hazards by engineering approaches) is successful in reducing the number of injuries due to road traffic accidents up to a certain extent. This study is focussed on analysing road traffic deaths caused by various road environment elements recorded by the police from 2000 to 2011 in order to determine their distribution, proportion and relationship with fatal accidents. The Chi-square test and Marascuilo procedure with 5% level of significance are used in this study. Based on locality, the number of road traffic deaths in rural area (66%) is significantly higher compared with that in urban areas (34%). Based on road category, the number of road traffic deaths is the highest for federal roads, whereas the highest rate of fatalities per kilometre is recorded for expressways. Based on road segment, the number of road traffic deaths is the highest for straight road segments, followed by bends. In addition, the number of road traffic deaths is the highest for Y/T junctions, followed by cross junctions. The lowest number of road traffic deaths is recorded for interchanges and roundabouts. The results show that only 11.25% of the total road traffic deaths are related to road defects. The highest proportion of deaths due to road defects (48.6%) is associated with lack of street lighting provision, whereas road shoulder edge drop-off and potholes contribute 15.4% and 11.2% of road traffic deaths, respectively. [ABSTRACT FROM AUTHOR]

This paper examines the design of the credit-based congestion management schemes that achieve Pareto-improving outcome in general two-mode networks. It is assumed that transit is a slower but cheaper alternative to driving alone. The distributional welfare effects of congestion pricing on users with the different value of time (VOT) in Liu and Nie (Trans Res Board 2283:34-43, 2012) are used in developing Pareto-improving credit schemes. We show that, similar to the single-mode model, the sufficient and necessary condition for the existence of a discriminatory Pareto-improving credit scheme is the reduction in the total system cost. A sufficient condition for the existence of an anonymous Pareto-improving credit scheme is also derived. A cross-OD subsidization scheme is proposed when the sufficient condition is not satisfied for each origin-destination (O-D) pair. Numerical experiments on the expanded Sioux Falls networks with a log-normal VOT distribution demonstrate that the proposed Pareto-improving scheme can generate positive net revenue in the presence of good transit coverage. [ABSTRACT FROM AUTHOR]

This paper models the relationship between vehicle miles traveled (VMT) on local and collector roads with an objective to predict local road VMT by using collector road VMT. Through a continuous approximation method typically used for vehicle routing, it first analytically reveals this relationship mainly as a function of roadway density ratios between multiple roadway classifications. This structural relationship suggests regression equations using density ratios or logarithmic values of them as the explanatory variables. The use of regression equations enables to account for varying spatial distributions of roadways and demand through parameter calibration. The proposed regression equations are proved good fits through computer simulation using distinct community road network topologies. In addition, practical data from Hennepin County of Minnesota, U.S.A. that encompasses Minneapolis indicates that our developed regression equations can work well. [ABSTRACT FROM AUTHOR]

In this study, we analyze the criticality of nodes in air transportation using techniques from three different domains, and thus, three essentially different perspectives of criticality. First, we examine the unweighted structure of air transportation networks, using recent methods from control theory (maximum matching and minimum dominating set). Second, complex network metrics (betweenness and closeness) are used with passenger traffic as weights. Third, ticket data-level analysis (origin-destination betweenness and outbound traffic with transit threshold) is performed. Remarkably, all techniques identify a different set of critical nodes; while, in general, giving preference to the selection of high-degree nodes. Our evaluation on the international air transportation country network suggests that some countries, e.g., United States, France, and Germany, are critical from all three perspectives. Other countries, e.g., United Arab Emirates and Panama, have a very specific influence, by controlling the passenger traffic of their neighborhood countries. Furthermore, we assess the criticality of the country network using Multi-Criteria Decision Analysis (MCDA) techniques. United States, Great Britain, Germany, and United Arab Emirates are identified as non-dominated countries; Sensitivity analysis shows that United Arab Emirates is most sensitive to the preference information on the outbound traffic. Our work gears towards a better understanding of node criticality in air transportation networks. This study also stipulates future research possibilities on criticality in general transportation networks. [ABSTRACT FROM AUTHOR]

The approximation of the traversal cost is a critical component of dynamic traffic assignment model. In link based traffic assignment, it assumes that the constraints sets are linear or convex and it is not realistic in general traffic networks. Comparing with the link based model, the path cost in the objective function of the path based traffic assignment model is implicitly nonlinear or non-convex, which is difficult to solve. In this paper, a path based traffic assignment model combining the generalized expansion method in M/G/c/c model with the point queue model is proposed to extend the link traversal cost to the travel cost along the path. Comparing with the link based model without considering intersection effects, this proposed path based model can take into account queuing delays between intersections and it is easy to implement. In order to validate the proposed path based model, a comparative experiment is implemented by comparing with the traditional travel cost models in Sydney traffic networks. Taking into account travel flow changes and blocking time, the proposed path based model is more effective for travellers from the uncongested traffic to congested traffic networks. In addition, the results from traffic assignment model show that the proposed model can achieve feasible results. [ABSTRACT FROM AUTHOR]

This paper addresses the discrete network design problem (DNDP) with emphasis on the environmental benefits. These benefits are traditionally quantified by emission models, which in general account for vehicle speeds, traffic flows and emission coefficients. An alternative approach for approximating the environmental impact of traffic is developed. This approach finds the route that keeps the most balanced speed profile throughout the route, which contributes to fuel consumption reduction. The paper formulates an optimization problem that includes the described approach for the DNDP. The solution of the problem consists of projects that contribute the most to the generation of such 'balanced speed routes'. The paper illustrates the problem and the solution for a real-size network with a medium-size set of candidate projects. [ABSTRACT FROM AUTHOR]

Peer-to-Peer (P2P) traffic is widely used for the purpose of streaming media, file-sharing, instant messaging, games, software etc., which often involves copyrighted data. From the past decade, P2P traffic has been contributing to major portion of Internet traffic which is still rising and hence is consuming a lot of network traffic bandwidth. It also worsens congestion of network traffic significantly and degrades the performance of traditional client-server applications. Popularity of various P2P applications has led Internet Service Providers (ISPs) to face various challenges regarding efficiently and fairly utilizing network resources. The traditional methods of identifying P2P traffic such as port-based and payload-based are proving ineffective due to their significant limitations and can be bypassed. Hence, new approaches based on statistics or behaviour of network traffic needs to be developed and adopted in order to accurately identify existing and new P2P traffic which emerge over the time. This article presents a survey regarding various strategies involved in identifying P2P traffic. Furthermore, conceptual analysis of network traffic measurement and monitoring is also presented. [ABSTRACT FROM AUTHOR]

As one of the essential components of Intelligent Transport Systems (ITS), Vehicular Ad Hoc Network (VANET) plays a significant role in enabling various on-road applications, most of which primarily rely on two-hop Vehicle-to-Infrastructure communications. To make such communications reliable and secure, it is significant to ensure that only the trustworthy vehicles are selected as relays. To tackle this challenge, this paper proposes a robust trust-based relay selection scheme, called PTRS, which, based on Dirichlet distribution, systematically integrates a set of unique features of VANET, e.g., hybrid architecture, high dynamics, into the traditional reputation system, with an objective to effectively differentiate the trust levels of the vehicles, meanwhile, preserving robustness. Besides, the location privacy of vehicles are preserved in our proposed scheme by using the technique of pseudonyms and trust levels instead of explicit reputation scores. Detailed security analysis is conducted, which shows that the proposed PTRS scheme is secure and robust against several sophisticated attacks in VANETs. In addition, a set of extensive simulations are carried out, demonstrating its effectiveness and accuracy. [ABSTRACT FROM AUTHOR]

Robotic swarms are decentralized systems formed by a large number of robots. A common problem encountered in a swarm is congestion, as a great number of robots often must move towards the same region. This happens when robots have a common target, for example during foraging or waypoint navigation. We propose three algorithms to alleviate congestion: in the first, some robots stop moving towards the target for a random number of iterations; in the second, we divide the scenario in two regions: one for the robots that are moving towards the target, and another for the robots that are leaving the target; in the third, we combine the two previous algorithms. We evaluate our algorithms in simulation, where we show that all of them effectively improve navigation. Moreover, we perform an experimental analysis in the real world with ten robots, and show that all our approaches improve navigation with statistical significance. [ABSTRACT FROM AUTHOR]

As global internet traffic continues to increase, network operators face challenges on how to efficiently manage transmission in their networks. Even though attempts are underway to make optical networks automatic, the majority of actions related to traffic engineering are still performed manually by the administrators. In this paper we propose an Automatic Hidden Bypasses approach to enhance resource utilization in optical networks. Our solution uses the software-defined networking concept to automatically create or remove hidden bypasses which are not visible at the network layer. The mechanism increases throughput and reduces transmission delays. [ABSTRACT FROM AUTHOR]

This study investigates different methods to visualise uncertainty in static representations of probabilistic traffic models predictions on road-networks. Although various graphical cues may be used to represent uncertainty it is not a priori clear which of them are most suited for this purpose, since their legibility, intelligibility and the degree to which they interfere with other graphical elements in a representation differ widely. Several graphical uncertainty representations were therefore developed and analysed in expert sessions. A selection of the initial set of uncertainty visualisations was further evaluated in a cognitive alternative task-switching experiment. The results show that graphical representations are able to convey uncertainty information relatively accurately, while some uncertainty visualisations outperform others. It depends on the model and scenario which representation is most suited for a given application. This paper presents an overview of possible graphic uncertainty representations and the considerations involved when applying them to uncertainty in traffic model visualisations. [ABSTRACT FROM AUTHOR]

Wireless network sensors and their use in traffic monitoring, traffic density determination or vehicle speed detection and classification have recently been the focus of interest for researchers. This article describes how a new sensor circuit was designed to deliver instantaneous, real-time and novel solutions as a vehicle detection system, which is more powerful than the nodes used in other studies, and gives results with smaller error margins due to its serial communication qualification. With the proposed logic algorithm, it was possible to categorise the instantaneous traffic status of a road in four levels: no traffic, mild traffic, heavy traffic and very heavy traffic. Additionally, with the nodes placed at the beginning and the end of the road, the number of vehicles per hour for a day was determined and traffic was analysed. Then, vehicles passing by were classified with a proposed classification algorithm and magnetic signature length (MSL) parameter as cars, minibuses, buses and trucks, and an accuracy rate of 95% was obtained. As the last application, the direction of motion of the vehicle on the x-axis as well as left-to-right or right-to-left directions was determined, and the result was 94% accurate. The simplicity of the proposed algorithms, the absence of any complex mathematical calculations, the low cost of the sensor node and circuit and the low power consumption of the communication system demonstrate the superiority of this system in comparison with other studies. [ABSTRACT FROM AUTHOR]

This study investigates the electric vehicle (EV) traffic equilibrium and optimal deployment of charging locations subject to range limitation. The problem is similar to a network design problem with traffic equilibrium, which is characterized by a bi-level model structure. The upper level objective is to optimally locate charging stations such that the total generalized cost of all users is minimized, where the user's generalized cost includes two parts, travel time and energy consumption. The total generalized cost is a measure of the total societal cost. The lower level model seeks traffic equilibrium, in which travelers minimize their individual generalized cost. All the utilized paths have identical generalized cost while satisfying the range limitation constraint. In particular, we use origin-based flows to maintain the range limitation constraint at the path level without path enumeration. To obtain the global solution, the optimality condition of the lower level model is added to the upper level problem resulting in a single level model. The nonlinear travel time function is approximated by piecewise linear functions, enabling the problem to be formulated as a mixed integer linear program. We use a modest-sized network to analyze the model and illustrate that it can determine the optimal charging station locations in a planning context while factoring the EV users' individual path choice behaviours. [ABSTRACT FROM AUTHOR]

Recent years have witnessed intensification of road traffic and, with it, the amount of substances emitted by vehicles. Such emissions need to be monitored for public health purposes. The aim of this study was to evaluate the impact of the highway traffic on the total content and bioavailability of Zn, Cu, Ni, Cd, Cr and Pb in nearby soils as well as influence of an acoustic screen on spatial distribution of the metals. The material included 40 soil samples collected from 15 research points located 5, 10, 25 and 50 m away from the road acoustic screen and from 4 points between the screen and the highway. Additionally, 5 research points were located next to the metal barrier. Selected physicochemical properties of soils were determined: soil texture, soil pH, TOC and CaCO content. The total content of heavy metals in the soils was determined by AAS after digestion in aqua regia and bioavailable forms in 1 M diethylenetriaminepentaacetic acid. The research found low impact of the highway traffic on the content of heavy metals in soils; however, due to a very short period of this potential impact (5 years), the moderately polluted category of geo-accumulation index of cadmium and high bioavailability of lead indicate the need of repeating the research within the next several years. Furthermore, the road acoustic screen significantly influenced spatial distribution of the metals in soils. [ABSTRACT FROM AUTHOR]

In software development, refactoring is a process that improves the system internal structure without altering its external behavior. Applying design patterns, which are common reusable solutions of several kinds of problems is widely adopted. This technique, however, raises a challenging issue that after applying design patterns the software system may not preserve some certain behavioral properties. This paper proposes a new approach to checking consistency between original software system and its evolution at both design and implementation phases. First, we formalize elements of software designs and programs. Methods, based on these formalizations, are proposed for verifying the design and implementation of the system. Finally, the paper presents a case study of Adaptive Road Traffic Control system to illustrate the proposed approach in detail. [ABSTRACT FROM AUTHOR]

Most studies published to date consider single noise sources and the reported noise metrics are not informative about the peaking characteristics of the source under investigation. Our study focuses on the association between cardiovascular mortality in Switzerland and the three major transportation noise sources-road, railway and aircraft traffic-along with a novel noise metric termed intermittency ratio (IR), expressing the percentage contribution of individual noise events to the total noise energy from all sources above background levels. We generated Swiss-wide exposure models for road, railway and aircraft noise for 2001. Noise from the most exposed façade was linked to geocodes at the residential floor height for each of the 4.41 million adult (>30 y) Swiss National Cohort participants. For the follow-up period 2000-2008, we investigated the association between all noise exposure variables [L(Road), L(Rail), L(Air), and IR at night] and various cardiovascular primary causes of death by multipollutant Cox regression models adjusted for potential confounders including NO. The most consistent associations were seen for myocardial infarction: adjusted hazard ratios (HR) (95% CI) per 10 dB increase of exposure were 1.038 (1.019-1.058), 1.018 (1.004-1.031), and 1.026 (1.004-1.048) respectively for L(Road), L(Rail), and L(Air). In addition, total IR at night played a role: HRs for CVD were non-significant in the 1st, 2nd and 5th quintiles whereas they were 1.019 (1.002-1.037) and 1.021 (1.003-1.038) for the 3rd and 4th quintiles. Our study demonstrates the impact of all major transportation noise sources on cardiovascular diseases. Mid-range IR levels at night (i.e. between continuous and highly intermittent) are potentially more harmful than continuous noise levels of the same average level. [ABSTRACT FROM AUTHOR]

Continuous and simultaneous measurements of ammonia gas (NH) and fine particulate ammonium (PMNH ) were performed in two distinct urban areas: Osaka, Japan, and Ho Chi Minh City (HCMC), Vietnam. Measurements were performed using a new online instrument. Two measurement periods were conducted during February 11-March 12, 2015 (cold period), and July 1-September 14, 2015 (warm period), at the urban site in Osaka, while 17 days of measurements, from May 21 to June 8, 2015, were conducted at the urban site in HCMC. The average NH concentration at the HCMC site was much higher than that at the Osaka site. The differences in the NH levels between the two cities are a result of their different emission sources. Traffic emission is a significant contributor to the NH levels within the urban area in Osaka. Conversely, the contribution of traffic emission to the NH levels in the HCMC urban area is negligible. With a population of around 8.5 million people living in the urban area of HCMC, the high NH level is due to human sources and poor waste management systems, especially because of the high temperature (30 °C) and dense population of the city (density up to 42,000 inhabitants per km). In contrast to the NH levels, the highest PMNH level occurred during the cold period at the Osaka site, and the average level at this site was higher than that at the HCMC site. The availability of atmospheric acids, low temperature, and high humidity facilitates the formation of ammonium. Our results indicate that NH plays a key role in secondary inorganic aerosol formation; therefore, it contributes to a significant amount of PM at the Osaka site. In contrast, the high levels of PM observed at the HCMC site are likely from road traffic emission, mainly motorcycles, rather than secondary inorganic aerosol formation. [ABSTRACT FROM AUTHOR]

Purpose In order to explore the effect of curb parking on dynamic traffic and formulate some reasonable and effective traffic management measures, the effects on capacity and traffic safety are studied. Methods Four road segments with curb parking were selected as the investigation location. Several traffic characteristics and parameters were then investigated and counted, including traffic flow volume, speed, headway and traffic conflict. Based on a reduction of lane effective width and the Gap Acceptance Theory, two effect models describing curb parking and road capacity were constructed. Considering the factors involved in motor vehicle conflicts (such as non-motor vehicle lane distribution and stopping sight distance), the effects of curb parking on both motor vehicle and non-motor vehicle traffic safety was analyzed, as well as pedestrian crossing safety. This case study analyzes both the capacity and traffic safety of all four investigation segments. Results Results show that the lane effective width of road segment with curb parking significantly influences the road capacity and impacts the traffic flow volumes of the parking lane and its adjacent lane. Conclusions Curb parking significantly effects traffic operation safety; however, it can be improved by implementing traffic safety management measures. [ABSTRACT FROM AUTHOR]

In order to ensure that traffic capacity is stable, and avoid incident congestion is anabatic, a double-layer ramp-metering model is proposed in this paper to control the traffic flow at each on-ramp, nearby incident congestion. The function of the lower model is to recognize where the incident congestion exists, based on an adaptive neural network, whose inputs are traffic flow, velocity and density. The outputs of the lower model are the section number where the congestion occurs and the ramp number which should be controlled. If there is congestion, the upper model would be activated. The function of the upper model is to calculate the control strategy. The required control ramp number from the lower model would be transmitted to the upper model together with the real-time state of controlled section. The upper model would calculate the ramp-metering ratio for each required ramp by minimizing the main time cost, total average queue length and equity index. In order to describe the traffic state more accurately, a tailored traffic model for urban freeway in China is established in the upper model to get the prediction, which considers the speed-limited value on main roadway, and corrects the calculation method of traffic flow state on origin point and exit ramp. The simulation results show the double model is effective to control the incident congestion induced by aggressive behavior. [ABSTRACT FROM AUTHOR]

This study considers a multi-trip split-delivery vehicle routing problem with soft time windows for daily inventory replenishment under stochastic travel times. Considering uncertainty in travel times for vehicle routing problems is beneficial because more robust schedules can be generated and unanticipated consequences can be reduced when schedules are implemented in reality. However, uncertainties in model parameters have rarely been addressed for the problems in this category mainly due to the high problem complexity. In this study, an innovative and practical approach is proposed to consider stochastic travel times in the planning process. In the planning model, the possible outcomes of vehicle arrivals and product delivery at retailers are systematically categorized and their associated penalty and reward are estimated. Thus, unanticipated costs for every scheduling decision can be incorporated into the planning model to generate vehicle routing schedules that are more robust facing uncertain traffic conditions. To solve the model that is characterized as an NP-hard problem in a reasonable amount of time, a two-stage heuristic solution algorithm is proposed. Finally, the stochastic model is compared with the deterministic model in both planning and simulated operation stages using the data of a supply chain in Taiwan. The result confirms that the schedule generated by the stochastic model is more robust than the one created with the deterministic model because undesired outcomes such as unfulfilled demands are greatly reduced. [ABSTRACT FROM AUTHOR]

Ensuring a minimum operational level of road networks in the presence of unexpected incidents is becoming a hot subject in academic circles as well as industry. To this end, it is important to understand the degree to which each single element of the network contributes to the operation and performance of a network. In other words, a road can become an "Achilles-heel" for the entire network if it is closed due to a simple incident. Such insight of the detrimental loss of the closure of the roads would help us to be more vigilant and prepared. In this study, we develop an index dubbed as Achilles-heel index to quantify detrimental loss of the closure of the respective roads. More precisely, the Achilles-heel index indicates how many drivers are affected by the closure of the respective roads (the number of affected drivers is also called travel demand coverage). To this end, roads with maximum travel demand coverage are sorted as the most critical ones, for which a method-known as "link analysis"-is adopted. In an iterative process, first, a road with highest traffic volume is first labeled as "target link," and second, a portion of travel demand which is captured by the target link is excluded from travel demand. For the next iteration, the trimmed travel demand is then assigned to the network where all links including the target links run on the initial travel times. The process carries on until all links are labeled. The proposed methodology is applied to a largesized network of Winnipeg, Canada. The results shed light on also bottleneck points of the network which may warrant provision of additional capacity or parallel roads. [ABSTRACT FROM AUTHOR]

This paper proposes test scenarios for evaluation of yaw stability for medium commercial vehicles. Maneuvering, speed, longitudinal tire force, tire-road friction coefficient, road slope, and load condition are considerable factors that have effect on the medium commercial vehicle yaw stability. After conducting an analysis on these six factors, effective test scenarios were developed. A sine with dwell test is well known as a test scenario for evaluation of performance of electronic stability control (ESC) on passenger vehicles and heavy commercial vehicles. The SWD test was modified considering medium commercial vehicle dynamics, and the ramp steer maneuver with maximum acceleration test was proposed. Simulation validation has been conducted using field test data. From simulation study, it was shown that the ESC system for medium commercial vehicle is effectively evaluated by the proposed test scenarios. [ABSTRACT FROM AUTHOR]

Population growth and the massive production of automotive vehicles have lead to the increase of traffic congestion problems. Traffic congestion today is not limited to large metropolitan areas, but is observed even in medium-sized cities and highways. Traffic engineering can contribute to lessen these problems. One possibility, explored in this paper, is to assign tolls to streets and roads, with the objective of inducing drivers to take alternative routes, and thus better distribute traffic across the road network. This assignment problem is often referred to as the tollbooth problem and it is NP-hard. In this paper, we propose mathematical formulations for two versions of the tollbooth problem that use piecewise-linear functions to approximate congestion cost. We also apply a biased random-key genetic algorithm on a set of real-world instances, analyzing solutions when computing shortest paths according to two different weight functions. Experimental results show that the proposed piecewise-linear functions approximate the original convex function quite well and that the biased random-key genetic algorithm produces high-quality solutions. [ABSTRACT FROM AUTHOR]

Bidirectional multicast mechanisms are used to support multi-point to multi-point (MP2MP) traffic such as video-conferencing. These mechanisms are deployed today in multi-protocol label switching (MPLS) networks using the connectionless mode in which traffic engineering (TE) features such as bandwidth reservation and fast reroute in case of link and/or node failure are not defined. Indeed, TE procedures are defined in MPLS for unicast and multicast point-to-multipoint (P2MP) traffic only. Hence, MP2MP traffic that requires TE procedures is carried out using a full mesh of P2P or P2MP paths. Similarly, a full mesh of P2P and P2MP backup paths should be predefined in order to fast reroute traffic in case of a node failure. This leads to a major scalability problem since MPLS TE paths incur heavy overhead burden on MPLS nodes (CPU and memory). In this paper, we emphasize on fast reroute procedures using MP2MP TE paths. In particular, we define the control plane procedures that should be established. In addition, we present a simulation study that demonstrates the scalability amelioration when using MP2MP TE paths for fast rerouting instead of full mesh P2P and/or P2MP paths. [ABSTRACT FROM AUTHOR]

Historic traffic information is valuable in transportation analysis and planning, e.g., evaluating the reliability of routes for representative source-destination pairs. Also, it can be utilized to provide efficient and effective route-search services. In view of these applications, we propose the k traffic-tolerant paths ( TTP) problem on road networks, which takes a source-destination pair and historic traffic information as input, and returns k paths that minimize the aggregate (historic) travel time. Unlike the shortest path problem, the TTP problem has a combinatorial search space that renders the optimal solution expensive to find. First, we propose an exact algorithm with effective pruning rules to reduce the search time. Second, we develop an anytime heuristic algorithm that makes 'best-effort' to find a low-cost solution within a given time limit. Extensive experiments on real and synthetic traffic data demonstrate the effectiveness of TTP and the efficiency of our proposed algorithms. [ABSTRACT FROM AUTHOR]

Reduction of greenhouse gas (GHG) emissions from transportation is an essential part of the efforts to prevent global warming and climate change. Eco-routing, which enables drivers to use the most environmentally friendly routes, is able to substantially reduce GHG emissions from vehicular transportation. The foundation of eco-routing is a weighted-graph representation of a road network in which road segments, or edges, are associated with eco-weights that capture the GHG emissions caused by traversing the edges. Due to the dynamics of traffic, the eco-weights are best modeled as being time dependent and uncertain. We formalize the problem of assigning a time-dependent, uncertain eco-weight to each edge in a road network based on historical GPS records. In particular, a sequence of histograms is employed to describe the uncertain eco-weight of an edge at different time intervals. Compression techniques, including histogram merging and buckets reduction, are proposed to maintain compact histograms while retaining their accuracy. In addition, to better model real traffic conditions, virtual edges and extended virtual edges are proposed in order to represent adjacent edges with highly dependent travel costs. Based on the techniques above, different histogram aggregation methods are proposed to accurately estimate time-dependent GHG emissions for routes. Based on a 200-million GPS record data set collected from 150 vehicles in Denmark over two years, a comprehensive empirical study is conducted in order to gain insight into the effectiveness and efficiency of the proposed approach. [ABSTRACT FROM AUTHOR]