Highway Sections Research Articles

Freeway crash risk prediction considering unobserved heterogeneity: A random effect negative binomial regression approach

Unobserved heterogeneity of crashes remains a significant issue for freeways that influence crash prediction, and therefore deserves much attention. Using a fusion data set of crash data, driving behavior data, and traffic flow data, this study explores the spatiotemporal heterogeneity of crash determinants for different freeway segments (e.g. Yixing section and Liyang section of Ning-Hang freeway of China) and then predict the crash probability. A random effect negative binomial regression model is built to investigate the contributing factors of the crashes. Remarkable differences are observed in the crash determinants for Yixing section (include average vehicle speed, hourly average traffic volume, average free speed, road segment length, and number of left lane-merging) and Liyang section (include average intensity of aggressive driving behavior, average kilometer traffic volume). The results found the traffic flow has a more significant impact on crashes than the driving behaviors. It is found that the crash probability is a monotone decreasing function when the predicted number of crash is 0. With the increase of the number of predicted crash, the crash probability gradually converges from a large value to 0. Then the probability of other predicted number of crashes (e.g. crash = 1, crash = 2, crash = 3) presents a quadratic parabola trends. The model comparison demonstrates that the proposed model outperforms conventional model, and the prediction performance for Liyang section is better than that of Yixing section. The research findings are interesting and important for preventing crashes.

Hydrogen station location optimization coupling hydrogen sources and transportation along the expressway

The appropriate siting of hydrogen refueling stations (HRSs) can contribute to reducing hydrogen costs and promoting the widespread adoption of hydrogen fuel cell vehicles (HFCVs). This study integrates hydrogen sources and transportation, aiming to minimize the unit hydrogen cost. Two models for hydrogen station siting along the expressway are established. For the selection of feasible station siting schemes under discrete conditions, we design a screening process and algorithm Taking a specific highway section as a case study, both models are optimized, resulting in the unit hydrogen cost of 50.44 CNY/kg and 51.69 CNY/kg, respectively. Optimization verification is conducted, with percentage variances of 6.61 % and 18.77 %, respectively. Furthermore, the study delves into the impacts of different hydrogen demand, hydrogen production capacities, and the maximum allowable spacing between HRSs on station siting for both models. This research provides significant insights for hydrogen station siting along the expressway.

Road safety inspections: Basic principles

Some European Union Directives which were implemented by the various Member States, have established the fundamental guidelines for safety inspections of road infrastructures, according to the principle of the independence of the inspectors with respect to both the owner of the infrastructure and of its manager. This article addresses the practical implementation of the guidelines based on some inspections carried out on motorway sections in Italy.

Experimental study on plastic deformation of alluvial silty sand under traffic cyclic loading

With the development of highway construction, alluvial silt is gradually used as roadbed filler, but its dynamic characteristics are less studied. Based on the highway section from Luanzhou to Qingtuoying of G508, the plastic strain and dynamic stress-dynamic strain development law of alluvial silty sand under cyclic loading are analyzed by GDS dynamic triaxial test. The results show that under the action of a small range of dynamic stress amplitude, the soil sample is not destroyed, and the number of cycles is 1000 times, which is the critical point at which the axial total strain gradually tends to be stable. When the dynamic stress amplitude is 300 kPa, the total axial strain increases linearly, and the soil sample is destroyed. The cumulative plastic strain of the alluvial silt is the smallest when the optimum water content is 8.0 %, the confining pressure is 80 kPa, and the frequency is 1Hz.At this time, the cyclic load has a dense effect on the soil, and the soil structure does not fail. The dynamic stress-strain relationship of alluvial silty sand conforms to the R. L. Kondner hyperbolic model. The greater the confining pressure and the closer the moisture content to the optimal moisture content, the greater the dynamic strength. The research results are helpful to provide reference for other similar projects.

Zoning of highways of the Cherkasy region according to the degree of formation of ecosystem relations

The research is due to the great attention paid to the preservation and restoration of biodiversity in the countries of the European Union. Purpose. Carrying out zoning of the Cherkasy region according to the degree of completeness of the formation of roadside landscapes ecosystemsю Methods. From a methodological point of view, zoning is considered as one of the main methods of geographical analysis a nd synthesis. Zoning performs the function of a general geographic method of organizing spatial diversity in the geographic envelope and systematizing territorial formations at the regional level, which makes it an essential element of a systematic approach in geography. Results. The monitoring parameters of the infrastructure components of the main highways of the Cherkassy region (Kyiv-Odesa and Vinnytsia-Uman) used by us can be used for zoning, provided they are combined into logically formed factor groups. In particular, we combined all the initial parameters into the following groups of factors: natural-geographic factor: geolocation (geographic coordinates), air temperature and humidity, natural radiation background; degree of anthropogenic impact: noise level, dustiness, some geochemical indicators, proximity (or remoteness) of the road surface from agricultural land; the degree of manifestation of ecosystem relations: the number of plant species and their recurrence, the presence of invasive species and those that are indicators of salinity and waterlogging, the presence of species included in the National Catalog of Biotopes of Ukraine. Based on the list of main groups of factors, the main indicator of zoning will be the degree of completeness of the formation of roadside ecosystems. Conclutions. Taking into account the activation of ruderal flora at the exits from gas stations, or on remote sections of highways, it can be asserted that in these locations the Le Chatelier-Brown principle is fully in effect, according to which the biosphere compensates for the harmful effects from the outside with its diversity. The author sees prospects for further research in the expansion of the list of objects, in particular, it will be very interesting to investigate the formation of ecosystem relations on secondary communication routes.

Judahella kangpla: a new marine ostracod from the Upper Triassic of Thailand

The record of Mesozoic marine ostracods from South-East Asia is poorly known. This lack of data has led to uncertainty regarding their diversity and geographical distribution during this key interval of the Phanerozoic. Here, we report ostracod fossils from the Rong Kwang-Ngao highway section in northern Thailand, type locality for Upper Triassic (Carnian) Kang Pla Formation of the Lampang Group. The studied material comprises almost 100 specimens, most representing a new species, Judahella kangpla sp. nov., which is the first to be formally described from the Upper Triassic of Thailand. The morphology of Judahella kangpla, together with its diagnostic normal pore pattern and sexual dimorphism are discussed. The stratigraphical and geographical distribution of Judahella from the Upper Permian to Upper Triassic is summarized. Although preliminary, our work adds significant information to the biodiversity of marine ostracods during the Triassic along the eastern Tethyan coast. Marie-Béatrice Forel [marie-beatrice.forel@mnhn.fr], Muséum national d’Histoire naturelle, CR2P, MNHN-CNRS-Sorbonne Université, 8 rue Buffon (CP38), 75005 Paris, France; Anisong Chitnarin [anisong@sut.ac.th], School of Geotechnology, Institute of Engineering, Suranaree University of Technology, 111 University Avenue, Mueang District, Nakhon Ratchasima Province 30000, Thailand.

Studying the predictability of crash risk caused by manual takeover of autonomous vehicles in mixed traffic flow

ABSTRACT This study explores how to reduce the cost of prediction as much as possible while ensuring the prediction accuracy of a real-time crash risk model. The extreme gradient enhancement (XGBoost) algorithm was used to predict the crash risk of autonomous vehicles in different sections of highway. The results show that the prediction performance of the model is the best when the threshold value is 0.05. Choosing two variables to predict can ensure high accuracy and simultaneously reduce the cost of prediction when the accuracy of crash risk prediction of the three sections can reach 73%, 62%, and 70%. However, when only one variable can be selected due to sensor or system failure, the speed difference between the takeover car and the front car can be chosen to achieve the greatest benefit. These findings could provide a reference for technicians to design safer and more economical autonomous vehicles.

ROADKILL OCCURRENCE OF Cerdocyon thous (Linnaeus, 1766) AND Lycalopex gymnocercus (G. Fisher, 1814) IN SOUTHERN BRAZIL

Despite being important for the country’s development, roads may have impacts on the ecosystems where they occur, as well as the wild populations that live there. Several species are at risk of being run over on the highways, including taxa considered common and abundant. Of these species Crab-eating-fox (Cerdocyon thous) and Pampas-fox (Lycalopex gymnocercus) are susceptible to the impacts of highways and as a result this study aims to evaluate the occurrence of roadkills of C. thous and L. gymnocercus in highways in the Araucaria Plateau, Rio Grande do Sul. Monthly surveys were conducted from May / 2016 to April / 2017, along eight sections of state and federal highways of Rio Grande do Sul, Brazil. The surveys were performed in a motor vehicle, searching for carcasses of the target species. 25 animals killed by running over were recorded, 18 were C. thous and seven L. gymnocercus, but no significant difference was observed between the species or sections evaluated. However, the asphalt highways with the highest traffic volume had the highest running over concentrations. The presence of crops along the roads can be attractive to many native species, and the absence of natural barriers facilitates access to the highways, increasing the risk of collision with vehicles. It is important that mitigating measures be implemented on the highways, in order to minimize the running over of wild fauna.

Short-term traffic flow prediction based on weather factors analysis and neural network

With the progress of urban transportation infrastructure and the construction of intelligent transportation system, sufficiently accurate traffic flow prediction is of increasing importance for urban planning and management. This paper based on traffic flow data in a section of highway in Los Angeles, USA, we combine external qualitative data such as weather and work calendars, analyze and process the factors significantly influencing traffic flow first, then train and test the traffic flow data by building machine learning Support Vector Regression (SVR) model and the Back Propagation neural network (BP neural network). The test results show that the BP neural network traffic flow prediction model incorporating the external environment is more accurate, and that the external environment has a significant impact on the traffic flow prediction problem. If more significantly influencing factors can be taken into account, or if the current algorithm can be optimized, the prediction accuracy will have further improved, thus effectively enhancing the efficiency and safety of traffic systems.

Introduction of a new index to assess pavement functional condition

AbstractFor most countries, the construction of the road network is completed to a great extent. As a result, the road operators have focused on the management of the current road constructions. The pavement management systems have been the determinative answer to the above need finding the optimal and more efficient solution which minimizes the maintenance cost. In this context, the present paper aims at the development of an index that assesses sections of road networks based both on the pavement essential demands and surface characteristics. This project presents a model for the rating of highway sections taking into consideration criteria and sub-criteria related to the pavement function. The developed model has been formed based on the opinion of a group of experts. The technique of the fuzzy analytic hierarchy process (FAHP) has been used to mathematically analyze the above opinions and manipulate uncertainty and subjectivity. This method ends up by calculating the weights of significance which are the factors of the index equation. The index is composed in combination with the variables which have come up from the regular measurements of pavement characteristics assessing the pavement functional condition. The results are compared to those of the regular AHP highlighting the degree of influence by the uncertainty of experts’ judgments in some factors of the index. Furthermore, the suitability and ease in the fitting of the FAHP method are verified in pavement management problems. In this project data related to the checks on surface characteristics in the National Highway Network are displayed.

Variable speed limit control strategy at the entrance and exit of freeway tunnel

In order to effectively reduce the accident rate of freeway tunnel section and improve the safety factor of tunnel section, variable speed limit control scheme at the entrance and exit of tunnel is presented from the perspective of safety. First, by considering the influence of tunnel section characteristics on vehicle operation, variable speed limit cells and variable length cells are added to improve the cell transmission model and establish a dynamic traffic flow model; Second, aimed at the minimum speed dispersion and the minimum change rate of tunnel illumination, and taken the fixed speed limit and the maximum speed difference as constraints, the variable speed limit control optimization model at the entrance and exit of the tunnel is established; Third, the genetic algorithm is employed to solve the control function with meeting the safety requirement of traffic operation. The results show that compared with the fixed speed limit mode, the implementation of variable speed control in tunnel group sections can significantly reduce the dispersion of running speed, which is conducive to traffic safety and operation efficiency.

Design of Drainage Downspouts Systems over a Road Embankment

Numerous studies have examined the complex relationship between factors like embankment downspout spacing, height, slope, and rainfall characteristics in the quest to find the best spacing for embankment downspouts. Defining the correct spacing between road drainage elements is of utmost importance in minimizing water flow on roadways. This paper presents a methodology based on numerical methods for the design of road drainage systems using the Iber model. The objective of the work is to propose a tool and criteria for analyzing the hydraulic behavior of runoff on highways, determine the appropriate drainage behavior, and apply the methodology in a case study. This case study is based on a straight highway section with slopes up to 5%, according to Spanish road design regulations. Different dimensions are considered for the chute, drainage channel, collection nozzle, and downspout over the embankment. Tests are carried out to evaluate the separation between downspouts, the longitudinal slope, and the size of the nozzles. The results show the suitable hydraulic performance of the model, besides providing the absorption capacity of each downspout. The influence of the nozzle size, the slope, and the width of the causeway on the draughts and velocities is analyzed. The influence of downspout spacing and nozzle type on road drainage design is determined. In summary, this article presents a methodology and criteria for the design of road drainage systems and shows the results obtained in a case study using the Iber model. The results help in understanding the influence of different variables on the hydraulic behavior of road runoff and provide relevant information for proper drainage design.

Inventory of road arborization on the urban section of BR-153 Gurupi-TO

Roadside tree planting involves integrating the road into the landscape. Therefore, the objective of this study was to assess the tree vegetation in the urbanized, duplicated section of BR-153 highway in Gurupi, Tocantins. Permanent plots were systematically established along the central and lateral medians, each measuring 10x10m (100m²) in size, totaling 146 plots in the central median (CM), 54 in the right lateral median (RLM), and 49 in the left lateral median (LLM). Within these plots, all tree individuals with a minimum height of 4.0m from the ground and a diameter at breast height (DBH) ≥ 5cm were sampled.In the inventory, a total of 260 individuals were counted in the central median, distributed across 24 species and 7 families, with a Shannon diversity index (H') of 1.98 and Pielou's evenness index (J') of 0.62. In the right lateral median, 92 individuals were recorded, representing 13 species and 5 families, with (H') of 2.13 and (J') of 0.83. In the left lateral median, 68 individuals were registered, comprising 15 species and 6 families, with (H') of 2.06 and (J') of 0.76, which is consistent with studies conducted in the region. The average height of the vegetation was 6.6m, and the mean diameter along the stretch was 29.99 cm. The species with the highest importance values were Tabebuia roseo alba (Ridl.) Sandwith, Delonix regia (Bojer ex Hook.) Raf., and Syagrus harleyi Glassman. The families with the highest importance values were Bignoniaceae, Anacardiaceae, Fabaceae, and Arecaceae. Of the species found, 57.14% are recommended tree species for highway tree planting. However, it is worth noting that the high number of individuals of the exotic species Delonix regia (flamboyant) may be considered a negative aspect, as it may compromise the diversity of the Brazilian flora by outcompeting native species.

Research on prediction method of expressway section traffic flow considering anomaly detection probability

AbstractReal‐time and accurate short‐term traffic flow prediction can provide a scientific basis for decision making by travellers and traffic management, and alleviate traffic congestion to a certain extent. The existing traffic flow prediction methods often encounter limitations in real‐time performance and accuracy due to the post‐processing required to rectify anomaly detection results during data pre‐processing. This paper presents a novel traffic flow prediction model, termed the With‐Anomaly Detection Probability (ADP) Attention‐Bidirectional Long‐Short Term Memory (BiLSTM) model. This model takes the probability of anomaly detection into consideration, integrating the anomaly detection outcomes as an inherent parameter into the traffic flow prediction framework. Additionally, the model incorporates an attention mechanism within the long‐short term memory network. Through a comprehensive simulation study utilizing actual measured traffic flow data from the Shanghai‐Chongqing Expressway, the effectiveness of the proposed model is rigorously evaluated. The prediction results show that the model proposed in this paper is a real‐time and accurate short‐time traffic flow prediction model compared with the basic models.

Research of Porous Asphalt Concrete Application on Highway Sections with The Increased Aquaplaning Danger Level

Statistics of road accidents show that even in the summer the number of accidents directly depends on weather conditions, and one such reason is aquaplaning in some parts of the road. Therefore, solving the issue of improving the road structure in such areas, while maintaining the regulatory strength, equality and coefficient of adhesion are relevant in road construction. The research allowed developing an improved mixture of porous asphalt mixture taking into account the physical-mechanical and operational properties. The construction of the road surface was also improved with the separation of the pavement layers, where porous asphalt mixture was used as the top layer, and the basalt canvas (impregnated) between the used construction levels was used. The mathematical calculation of the road was improved taking into account the physical phenomena occurring between the car and the road surface in the presence of water. The speed limits were calculated, and the thickness of the fluid layer was taken into account as well. The authors of the article also paid attention to the influence of road roughness on the speed limit.

Preliminary assessment of road dust from Portuguese motorways: chemical profile, health risks, and ecotoxicological screening

Among non-exhaust emissions, road dust resuspension represents a rather important contribution to particulate matter in urban areas. This study aimed to achieve a chemical characterisation of road dust particulate matter (PM10) on two motorway sections, one rural and one urban, and to explore the related health and ecotoxicological risks. Measured PM10 dust loadings reached very low levels (0.66–1.49 mg m-2) compared to equivalent studies in other road environments in Portugal and other countries. Emission factors ranged from 33 to 62 mg veh−1 km−1. The carbonaceous content represented 14% of the total PM10 mass, whereas the highest contribution to the mass was given by mineral matter. Elements such as Si, Al, Ca, Fe and K accounted for almost three quarters of the total element mass for all samples, whilst Cu and Zn, mostly associated with brake and tyre wear, were the most enriched elements in relation to the soil composition. Nonetheless, Ti and Zr presented the highest non-carcinogenic risks for human health. Despite the low amounts of particulate matter in the aqueous solution, the ecotoxicological screening with the Aliivibrio fisheri bioluminescence inhibition bioassay allowed to classify the samples as toxic.

Concrete durability evaluation in new built pavement sections of expressways in Poland

A review of concrete durability at several sections of the new built expressways in Poland is presented. Two-layers jointed plain concrete pavements were constructed using a slip-form technology. For freeze-thaw and deicing salts durability of concrete the specified air void properties, including the spacing factor and the microvoids content, was evaluated on core specimens drilled from the constructed pavements. The observed system of fine air voids indicates optimal features for increased frost and scaling resistance without a significant negative impact on strength. The correlation was established between the microvoid content in the hardened concrete and the data of the Super Air Metre on fresh concrete mix was established. Concrete durability in high moisture environment, combined with fatigue traffic load and external supply of alkaline deicing salt solutions, was considered using newly developed principles of nonreactive aggregate selection. The aggregate selection based on petrographic analysis and the assessment of expansive behaviour of concrete was fully confirmed using the performance tests with external supply of sodium chloride. The suitability of the established methodology for durability acceptance testing for exploration of alternative materials for paving is discussed.

ANALISIS KECEPATAN KENDARAAN DAN KINERJA RUAS JALAN RAYA KAPAL AKIBAT AKTIVITAS RUMAH SAKIT MANGUSADA KAPAL, MENGWI, BADUNG

Mangusada Hospital is one of the hospitals in Badung Regency, which is located in Kapal Village. Hospital activities during operating hours will directly affect the smoothness of traffic on the roads around the hospital caused by the activity of entering and leaving vehicles to or from the hospital. To find out the performance of the Ship Highway section, a research was conducted in the area for three days, namely Monday and Friday representing working days, Sunday representing holidays. Analysis of road performance using the 1997 MKJI calculation procedure for urban road sections. Based on the results of data analysis it is known that the highest vehicle traffic volume on Monday was 3046.05 pcu/hour occurred at 07.15 WITA -08.15 WITA, on Friday it was 2802 pcu/hour occurred at 07.00 WITA - 08.00 WITA, Sunday at 2372.9 pcu/hour occurred at 16.45 WITA - 17.45 WITA. The level of road service during Monday's peak hour was at level C with a degree of saturation value of 0.59, the average speed of light vehicles reached 39 km/hour. The condition of the vehicles at the road service level illustrates that traffic flow conditions are still stable, travel speed and freedom of movement are affected by the large volume of traffic so that the driver can no longer choose the desired speed

An over-the-horizon potential safety threat vehicle identification method based on ETC big data

Smart cars rely on sensors like LIDAR and high-precision map-based perception for driving environment sensing. However, they can't detect low-speed vehicles beyond visual range, affecting safety and comfort. Manual vehicles face similar challenges. Low-speed driving contributes to expressway accidents due to limited visibility, road design, and equipment performance. To enhance safety, an over-the-horizon potential safety threat vehicle identification method using ETC big data is proposed. It consists of three layers. The first layer is the vehicle section travel speed sensing layer based on the wlp-XGBoost algorithm. The second layer is the in-transit vehicle position estimation layer based on the DR-HMM algorithm. The third layer is the Multi-information fusion of potential safety threat vehicle identification layer. Dynamic real-time detection and identification of potential safety threats in expressway sections were achieved, and simulations were conducted using real-time ETC data from Quanxia section on an ETC platform. Results show accurate prediction of vehicle speed and position in different road sections and traffic situations, with over 95% accuracy and recall in identifying potential safety threat vehicles. It perceives changes in the traffic conditions of road sections in real-time based on the changing trend of potential safety threat vehicle numbers, providing a vital reference for speed planning and risk avoidance.

Traffic monitoring at the planning stage of an intelligent transport system (on the example of the city of Omsk)

The article presents a variant of substantiating the choice of sections of the road network for collecting data and conducting an analytical review regarding information on traffic flows at the stage of implementing an intelligent transport system. Today, this issue is relevant. This is due to the approval of the "Concept for the creation an intelligent transport systems for the Omsk region in 2022". The authors considered the main types of traffic monitoring. The main indicators of the local project for the implementation of an intelligent transport system have been established. A map is presented with the recommended location of sections of highways and stationary posts for recording traffic parameters for monitoring on the road network of the city of Omsk. A comparative analysis of methods for examining traffic parameters at stationary posts and with the help of a control vehicle is presented. Keywords: intelligent transport system, traffic management, traffic monitoring, traffic flow parameters, road network