Fatigue Life Predictions for a European Pavement Test Section Subjected to Individual and Platoon Truck Configurations

Truck platooning for the transportation of loads is a strategy recently proposed by the automotive sector to cope with traffic congestion, fuel consumption, and operational costs. This new way of configuring trucks changes the typical pressures pavements structures experience. For this reason, the research efforts of the pavement sector should be aligned with the automotive sector to propose road-friendly platoon configurations. This is one of the objectives of the European project ENSEMBLE. ENSEMBLE, as indicated by its acronym, works on ENabling SafE Multi-Brand pLatooning for Europe. In this context, the present study presents a real scale test done in the Applus IDIADA facilities to evaluate the fatigue behavior of a pavement structure subjected to individual and platoon truck configurations. The effects of parameters such as traffic distribution through the year and by time of day, percentage of platoons, truck loads, number of trucks in platoon configuration, lateral wandering, and inter-truck distances were evaluated. The study’s findings revealed that the reduced rest times between trucks in the platoon configuration reduce the recovery time of the asphalt layers, increasing the fatigue damage to the pavement at high temperature conditions. This underlines the need for further research to allow the proper implementation of truck platoons. For example, research is needed to define strategies to make truck platoon configurations more pavement-friendly and analyze the costs associated with the changes in the required road maintenance/rehabilitation treatments, among others.

On stability of distributions of WhatsApp traffic characteristics

This paper deals with the main methods of traffic classification and describes the functional scheme of a test bench and the test procedure. It provides the results of verifying the hypothesis about the stability of distributions of WhatsApp traffic characteristics. The delivered test results in this paper emphasize the influence of certain traffic characteristics on the final traffic distribution form. In addition, the comparison of the results obtained for the entire set of tests and the results received for individual test sets reveals the absence of other critical traffic characteristics significantly influencing the distribution form concluding in the need for further research. The paper concludes that the stability pattern of distributions of WhatsApp traffic characteristics can be obtained and visualized after more critical traffic characteristics are revealed and processed in similar tests. This paper stands as a pioneer research in assessing the traffic analysis and implementing the results in applied science.

Determination of the required amount of traffic of suburban trains, taking into account all-day and intraday irregularities in passenger traffic distribution

Objective: Automation of processing data on passenger traffi c in an arbitrary direction in order to determine the number of “threadsˮ in the time schedule for suburban passenger traffi c in the future. Verifi cation of the adequacy of the existing infrastructure and design solutions for reconstruction in terms of ensuring the required throughput capacity of railway lines. Methods: The calculation of the number of trains is carried out by mathematical modeling of passenger traffi c distribution by hours of the day on each day of the week of the initial month. The identifi cation of trains with non-daily destination is made by comparing the calculation results for each day of the week. Results: An algorithm has been developed for calculating on a computer the perspective amount of suburban train traffi c, taking into account the uneven distribution of passenger traffi c by hours of the day and days of the week. Practical importance: The data obtained using the presented algorithm makes it possible to simplify the development of advance time schedules, taking into account the needs of the population in transportation. The results of the work can be used in feasibility studies for the reconstruction of station layout development and passenger devices, as well as serve as the basis for the technical re-equipment of lines in order to increase their throughput (replacement of signaling and communication equipment, construction of second main tracks, reconstruction of yard necks, etc.). The results of the calculation also make it possible to identify schedule “threadsˮ for withdrawal of trains on days of the week when they are not in demand, but at the same time take into account non-daily trains when developing a standard time schedule. The form of presentation of the results takes into account the spatial irregularity of passenger traffi c and makes it possible to distinguish zonal trains.

Improving A/B Testing on the Basis of Possibilistic Reward Methods: A Numerical Analysis

A/B testing is used in digital contexts both to offer a more personalized service and to optimize the e-commerce purchasing process. A personalized service provides customers with the fastest possible access to the contents that they are most likely to use. An optimized e-commerce purchasing process reduces customer effort during online purchasing and assures that the largest possible number of customers place their order. The most widespread A/B testing method is to implement the equivalent of RCT (randomized controlled trials). Recently, however, some companies and solutions have addressed this experimentation process as a multi-armed bandit (MAB). This is known in the A/B testing market as dynamic traffic distribution. A complementary technique used to optimize the performance of A/B testing is to improve the experiment stopping criterion. In this paper, we propose an adaptation of A/B testing to account for possibilistic reward (PR) methods, together with the definition of a new stopping criterion also based on PR methods to be used for both classical A/B testing and A/B testing based on MAB algorithms. A comparative numerical analysis based on the simulation of real scenarios is used to analyze the performance of the proposed adaptations in both Bernoulli and non-Bernoulli environments. In this analysis, we show that the possibilistic reward method PR3 produced the lowest mean cumulative regret in non-Bernoulli environments, which proved to have a high confidence level and be highly stable as demonstrated by low standard deviation measures. PR3 behaves exactly the same as Thompson sampling in Bernoulli environments. The conclusion is that PR3 can be used efficiently in both environments in combination with the value remaining stopping criterion in Bernoulli environments and the PR3 bounds stopping criterion for non-Bernoulli environments.

Power-law distribution found in city-scale traffic flow simulation

Origin of a power-law in traffic-volume distribution found in traffic simulations of Kobe city was studied. The traffic distribution which was obtained from a shortest path search with randomized OD (origin-destination) set in Kobe city digital map obeys power-law. The toy model that Cayley tree is embedded in the network is also verified. It is theoretically shown that the traffic distribution with all possible OD set in a Cayley tree obeys power-law like distribution. With randomized OD set, the distribution is diffused from the theoretical point sets. Relationship between these facts and the origin of power-law is discussed.

Optimization of lane-changing advisory of connected and autonomous vehicles at a multi-lane work zone

The work zone with lane closure will be an active bottleneck due to vehicles’ mandatory lane-changing conflicts. The emerging Connected Autonomous Vehicle (CAV) technology provides opportunities for vehicle motion planning to improve traffic performance. However, the literature using CAV technology mainly focuses on single-lane lane-changing control in the merging area. The algorithm dealing with multi-lane lane-changing control is absent. In this paper, a simulation system with a lane-changing optimal strategy embedded for the multi-lane work zone is presented under the heterogeneous traffic flow. First, the road upstream of the work zone is divided into several segments, and an optimal multi-lane lane-changing algorithm is designed. It is recommended that CAVs, on the closure lane and the merged lane, change lanes on each segment to balance traffic distribution and minimize traffic delay. Second, to validate the algorithm proposed, a typical three-lane freeway with one-lane closed for the work zone is researched, and the simulation platform based on cellular automata is developed. Third, the advantages of multi-lane control strategies are studied and discussed in traffic efficiency improvement and collision risk reduction by comparing previous lane-changing control algorithms.

Trafficking in persons: cluster analysis of sending and receiving countries

The objective of this article is to deepen the understanding of the problem of human trafficking by analyzing the patterns of the distribution of traffic across countries, based on international statistics on various socio-economic indicators. We conducted cluster analysis using neuro network grouping algorithm of Kohonen self-organizing maps, basing on 44 variables reflecting different social and economical aspects for 144 countries. Countries were grouped according to the type and level of risk of trafficking-related crimes, and traffic distribution maps were built based on generally accepted hypotheses about traffic factors. As a result of the study, a number of hypotheses explaining the nature of traffic were tested. The results reveal the linkage between the risk of incoming and outgoing trafficking and the socio-economic parameters of the countries and groups.