Highways In Brazil Research Articles

Evaluation of models for estimating free-flow speed on two-lane rural highways in Brazil

The objective of this article was to evaluate different models found in the literature to estimate the free-flow speed (FFS) on Brazilian two-lane rural highways. The models available in three editions of the Highway Capacity Manual (HCM) and two adaptations of the manual were evaluated to reproduce the behavior found on Brazilian highways. This evaluation was carried out based on traffic data collected in nine homogeneous segments of a Brazilian highway (MG-050) in the state of Minas Gerais. The FFS results estimated with the analytical methods were compared with the FFS data observed directly in the field. It was identified that there is no correlation between the FFS values produced by the analytical methods and the values found in the field. However, two models, one HCM2000 and another HCM2022, adapted to Brazilian traffic conditions, have similar average FFS values to those observed in the field.

The Effects of Roads on Trade and Migration: Evidence from a Planned Capital City

A large body of literature studies how infrastructure facilitates trade. We ask whether infrastructure also facilitates migration. Using a general equilibrium trade model and rich spatial data, we study the impact of a large, plausibly exogenous shock to highways in Brazil on both goods and labor markets. We find the highway system increased welfare by 2.8 percent, of which 76 percent was due to reduced trade costs and 24 percent to reduced migration costs. An implication of costly migration is spatial heterogeneity in benefits: the range of welfare improvement is 1 to 15 percent, as opposed to uniform gains with perfect mobility. (JEL H54, H76, O18, R23, R42, R53)

Electric Vehicles Charged with Solar-PV: A Brazilian Case Study for 2030

Electric vehicles and photovoltaic power stations can play an important role in replacing fossil fuels. This article presents a case study on the placement of charging stations powered by photovoltaic energy along an important highway in Brazil. A demand model was adopted to elaborate three scenarios for 2030 with different participation levels of electric vehicles in the Brazilian market. An optimized allocation model was used to derive the location and number of charging stations required to meet the charging demand. The results provided a list of adequate locations for installing the charging stations and offered insights into the consumed electricity and greenhouse gas emissions that could be mitigated by these actions. A financial analysis was conducted, and it was determined that the charging costs, based on the Internal Rate of Return calculation, were 10%. These costs were compared to the fueling costs of other traditional vehicles. The results showed that the costs can be 72% lower than the cost of refueling current conventional automobiles. The results of this study can serve as a reference in the public policy debate, as well as for investors in fast charging stations.

Trends in road accidents on Brazil's highways: Evidence of persistence using fractional integration.

This paper deals with the analysis of trends in road accidents on highways in Brazil. We use time series techniques based on fractional integration that allow us to determine if exogenous shocks in the data have transitory or permanent effects depending on the order of integration of the series. Our results indicate that a low degree of long memory was detected in the series with shocks having thus transitory effects over time. We further find that the number of accidents have been reducing over time, though in the presence of negative shocks, the recovery is not going to be immediate due to the long memory nature of the data. Despite the absence of relevant investment relating to infrastructure expansion, it is worth mentioning the consolidation of a nationwide tolled road system in Brazil involving concessions to private administrators, alongside more severe traffic laws that can impose limitations on driving licences.

Wild fauna as roadkill on a highway in the semiarid region of northeastern Brazil

The death of wild vertebrates run over by motor vehicles on highways is one of the main causes of the loss of wildlife diversity. The aim of the present study was to investigate the diversity of wild fauna in roadkill incidents on a stretch of highway in the semiarid region of Brazil. The survey was conducted between March 2020 and May 2021 through active searches using a motorcycle. Killed vertebrates were analyzed and photographed in situ. Wild fauna was studied based on ecological descriptors, speed of movement and average rate of roadkill incidents. We compared total observed richness to that expected using nonparametric estimators. A total of 464 road-killed vertebrates were represented by two species of amphibians, 17 reptiles, 17 birds and 10 mammals. Amphibians were the most affected, totaling 245 individuals. Colubridae was the family with the largest number of species affected. Boiruna sertaneja and Boa constrictor were the only medium-size to large snakes killed. Herpailurus yagouaroundi and Leopardus tigrinus are respectively categorized as “least concern” and “vulnerable” according to the IUCN. The species accumulation curves continued to rise, showing no sign of approaching to an asymptote. Chao 2 and Jack 2 were the main estimators for road-killed wild vertebrates considering total richness. The diversity reported here is considered to be underestimated and greater monthly sampling efforts are required. Conservation strategies are urgently needed for the protection of wild vertebrate fauna to mitigate the staggering loss of biodiversity caused by the construction and operation of roads and highways in Brazil.

Evaluation of Moisture Susceptibility of Asphalt Mixtures: Influence of Aggregates, Visual Analysis, and Mechanical Tests

Asphalt pavement failure is directly related to the traffic and climate effects. Temperature and moisture severely impact pavement service life. It is known that moisture changes the stiffness and stress–strain distribution and all the mechanical behaviors of the mixture/structure. There is a huge interest in studying the impact of water on the behavior of flexible pavements, mainly on freeze–thaw regions under tropical climates with high rainfall levels. The scope of the present paper was to check the susceptibility to moisture-induced damage of dense asphalt mixes produced and applied on highways in Brazil’s southernmost region using different laboratory tests: visual adhesion of coarse aggregate; tensile strength ratio (TSR), and dynamic modulus ratio (DMR). Thus, this study evaluated the morphological, chemical, and mineralogical properties of aggregates from 11 quarries, as well as the interaction between aggregates and the respective bituminous binders. Rocks with high Si contents performed worse in visual adhesiveness tests; chemical ratios such as Fe/Si above 1 and Ca/K above 5, as well as the rougher texture of aggregates, considerably improved the coating, reducing the failures in adhesion. Results of TSR and DMR, after applying the induced moisture damage cycle, indicated greater susceptibility to conventional binders than mixtures containing modified binders in their composition. The action of moisture damage for most mixtures caused a reduction in strength and stiffness, warning of a decrease in the binder’s ability within the mixture, completely changing the distribution of efforts within the structure. Therefore, from this study, it is possible to suggest using DMR instead of TSR to assess susceptibility to moisture damage.

Epidemiology of tobacco use and nicotine dependence in truck drivers.

To investigate the epidemiology of tobacco use and nicotine dependence in a sample of truck drivers in Brazil. Between 2015 and 2016, a cross-sectional study was conducted on 624 truck drivers who operate on the BR-050 highway in Brazil. Participants were interviewed about sociodemographic data, occupational characteristics, mental health, behavioral data, and tobacco use. Then, the Fagerstrom test for nicotine dependence (FTND) was used to verify nicotine dependence in smoking truck drivers. Logistic regression and linear regression were also used to verify factors associated with tobacco use in the previous 30 days and nicotine dependence scores, respectively. The prevalence of tobacco use among truck drivers was 21.1% (n = 132;95%CI: 18.1-24.5). Of the total number of smokers who responded to the FTND (n = 118; 89.4%), most had high/very high nicotinic dependence (68.6%; 95%CI: 59.8-76.3). Tobacco use was associated with absence of religion (adjusted odds ratio [AOR]: 2.60; 95%CI: 1.35-5.01), employment relationship of the contract (AOR = 1.98; 95%CI: 1.26-3.13); > 12 hours daily working time (AOR = 1.80; 95%CI: 1.09-2.98) and alcohol use in the previous 30 days (AOR = 2.92; 95%CI: 1.86-4.57). Irregular physical activity was associated with higher scores of nicotine dependence (β = 1.87; 95%CI: 0.55-3.19). The results showed a high prevalence of tobacco use and high/very high nicotine dependence among the truck drivers.

Binary logistic regression model applied to data on accidents occurred on federal highways in Brazil

Accidents on federal highways in Brazil lead to social and economic impacts on the country. Data from the Federal Highway Police reveal that thousands of people lose their lives in these accidents year after year. This paper aims to examine the factors that influence the probability of death based on the occurrence of the accident. The estimation of a binary logistic regression model took place, in which the event of interest is the circumstance of death in an accident with data from 2021. Following variable selection procedures, it was possible to obtain the final model, which was later validated with data from 2022. The accuracy of the model for both 2021 and 2022 data was around 70%. Then, the odds ratio was calculated between some distinct categories, and how much of an increase in accident lethality it generates compared to the reference category. For example, in a crash, a pedestrian is 15.6 times more likely to die when compared to the driver, while a cyclist is 5.3 times more likely to die. Although most accidents have a human cause, some results show the need of public policies that can help reduce these tragedies. To explain the model, a dashboard was created in a way that the user is able to obtain the probability of death by selecting specific accident characteristics and those involved.

Construction of Prospective Scenarios through the MOMENTUM Method: a case study on Federal Highways in Brazil

The main transport mode in Brazil is road transport. Therefore, highways play an important role in moving the country's economy. In the last survey on their conservation status in 2021, it was found that more than 60% of Brazilian roads were considered unsatisfactory. Therefore, the objective of this work is to prospect scenarios for federal highways in Brazil, from the Momentum Method. To this end, visits and inspections were carried out, from Unmanned Aerial Vehicles, on two of the main highways that cross the country: the BR-230 and the BR-101. The results, after the modeling of the problem, indicated three possible scenarios for the Federal Highways, due to the variables dollar price, investment, fuel price, and economic crisis, which have significant impact and dependence on the evaluated system: scenario "Sea of Holes", scenario "Only necessary" and scenario "Cruising Speed”.

Origin, evolution, and constructive elements of the Estrada de Mangaratiba, the first highway in Brazil

RESUMO O artigo discorre sobre aspectos históricos relacionados à definição do traçado, das técnicas de construção e degeneração da Estrada Imperial de Mangaratiba, primeira estrada de rodagem do Brasil, inaugurada em 1857. Construída para facilitar o escoamento de café produzido no Vale do Paraíba e sul de Minas Gerais, a Estrada de Mangaratiba tem sua história associada a importantes eventos do período, responsáveis por sua concepção e por seu abandono após um curto período de existência. Milhares de homens trabalharam em sua construção, ocupados com cortes da mata, nivelamento e, principalmente, em atividades relacionadas ao desmonte, transporte e preparo de toneladas de rochas, sua principal matéria-prima. A pesquisa de campo revelou que as pedras hoje expostas em trechos não asfaltados da estrada correspondem aos alicerces da antiga via, construída segundo o método do engenheiro escocês Thomas Telford sob coordenação do inglês Edward Brainerd Webb e não ao pavimento superior, como é popularmente aceito. A Estrada do Atalho, que lhe antecede, apresenta registros de diferentes modelos de pavimentação, compatíveis com técnicas herdadas dos antigos romanos. Todas as rochas utilizadas em ambas as estradas são de procedência local, extraídas com uso de explosivos de jazidas adjacentes às margens das vias, incluindo as cantarias da Ponte Bela, popularmente tidas como de origem portuguesa.

Felidae (Carnivora) as roadkill on highway in the Semiarid Region of Northeast Brazil

The death of wild vertebrates by roadkill on highways in Brazil mainly threatens endangered fauna. The aim of the present study was to report roadkill deaths of endangered felids on the PB-400 highway between the Municipalities of Cajazeiras and Monte Horebe, in the State of Paraíba, Northeast Brazil. Two individuals of Herpailurus yagouaroundi and one of Leopardus tigrinus were found, which are respectively listed as vulnerable and endangered. These results show the need for actions by the government and civil society for better management regarding the conservation of wild medium-sized felines and mitigating actions to avoid the death of wild fauna on highways.

Analysis of no-passing zones to assess the level of service on two-lane rural highways in Brazil

The highway capacity manual (HCM) is used to assess the level of service on two-lane rural highways in several countries, including Brazil. The 6th version of the HCM will address the capacity and level of service for two-lane highways based on follower density (FD). Studies have been conducted in Brazil to obtain a suitable method for calculating the level of service on two-lane highways. However, there are no studies that have determined the impact of no-passing zones involving FD, which is the main objective of this research. To achieve this goal, a set of traffic data was obtained from highway segments with the primary purpose of calibrating and validating the VISSIM traffic simulator used in this study. Using the simulator, traffic data were generated in hypothetical highway segments with a wide range of geometric and traffic characteristics. Traffic relationships for the simulation data were adjusted for the following conditions: (i) without no-passing zones, and (ii) with no-passing zones. The results of the analysis indicate that the models proposed in this study produce level of service and FD values close to values observed in the field.

Fatigue safety assessment of longitudinal and transverse reinforcements for concrete girder bridge designs

Highway concrete bridges are subjected to fatigue, with stress cycles from the traffic defining the fatigue lives of reinforcement and concrete. Most existing studies on fatigue reliability of bridges address bending, ignoring the fatigue effect on stirrups. This paper evaluates the service life and reliability indexes, from the fatigue point of view, of longitudinal and transverse reinforcements of several concrete girders (prestressed and reinforced) for new bridge designs. Traffic loads are considered as measured by a high-speed weigh-in-motion system at an important highway in Brazil. It is found that reliability indexes for longitudinal reinforcements tend to decrease with the increase of “span length/girder height” ratio and reliability indexes for stirrups tend to increase with the introduction of intermediate crossbeams. Safety levels of stirrups are usually found to be lower than those of longitudinal rebars and tendons, especially for reinforced girders. It is found that deterministic fatigue live estimates lower than 50 years correspond to unsatisfactory reliability indexes (probabilistic analysis).

Electromagnetic Launching System as an Alternative to Non-Destructive Sonic Wave Generation for Steel Bar Length Determination

Soil nailing system is widely used along highways in Brazil. Non-destructive techniques have been used to estimate the length of installed soil nails. Sonic Echo and Impulse Response techniques evaluate the bar length using sonic wave propagation. The methods are similar and consists in generate an impact with a hammer. Results may be affected by this non-standard procedure. This paper aims to propose an automated sound wave generation in order to carried out tests quickly, with reproducibility and without operator dependence. An electromagnetic launching system was developed, which uses a projectile in place of the hammer, and the electromagnetic force instead of human force. The sound data was received by a microphone and sent to the computer by a microcontroller, making the system compact and portable. Projectile output speed optimization and impact reproducibility were analyzed. Nails length were obtained by both time and frequency domain data analysis. Results showed high reproducibility under the same initial condition. Propagation velocity presented a relative error less than 1% for steel bar with length of 1 m.

Life cycle inventory and impact assessment for an asphalt pavement road construction—a case study in Brazil

Currently, there are no life cycle impact data available on the construction of road infrastructure in Brazil. This study aimed to determine several environmental impacts associated with the construction of an asphalt-paved highway in Brazil using the life cycle assessment approach and road construction data available from two Brazilian highways. The results from this study can potentially raise awareness to the importance of life cycle thinking in road construction in Brazil. The processes considered within the asphalt road pavement product system were extraction and processing of sand, gravel, and pitch; transportation of these inputs; and machinery use and operation, including direct and indirect emissions, raw materials, and electricity/fuel. Inventories available in Ecoinvent were used, and processes relevant to the Brazilian scenario were selected, with modifications made when necessary. The ReCiPe method was used to calculate the impacts, and for each category a second method was used to verify the results. The impact categories analyzed were global warming potential (GWP), terrestrial acidification potential (TAP), ozone depletion potential (ODP), freshwater eutrophication (FWEP), marine eutrophication (MEP), and freshwater ecotoxicity (FWECP). In addition, an alternative scenario was considered by substituting diesel with biodiesel in the transportation trucks. Gravel production was the main contributor to TAP (56% based on ReCiPe) and MEP (62%) categories. It was also a significant contributor to the GWP (16%), FWEP (25%), and FWECP (33%) categories. Transport of raw materials was the most impactful process in the GWP (58%), FWEP (55%), and FWECP (52%) categories. Pitch production was the major contributor to the ODP category (57%). The impact from sand production was negligible for all categories. Machinery operation had a small contribution in all impact categories (less than 14%). The different assessment methods used for each category indicated similar percent contributions for all processes considered (gravel, sand, pitch, transport, and machinery). Substitution of diesel with biodiesel caused an increase in the total impact for all categories, except for ODP. Gravel and pitch production, as well as raw material transport, were the most impactful processes in road construction. Therefore, strategies to reduce the impacts of road construction projects should focus on these three processes. In particular, investigation of the environmental impact, using a life cycle approach, of substituting gravel and pitch with alternative or recycled materials should be carried out for the Brazilian context.

Multiple correspondence analysis applied to the study of the relationship between traffic crashes and precipitation on a highway in Brazil

A incorporação de dados meteorológicos em pesquisas envolvendo o estudo de acidentes é considerada como essencial quando se objetiva analisar o comportamento de acidentes rodoviários. Neste contexto, o presente trabalho pretendeu explorar a existência de correlação entre ocorrência de acidentes rodoviários e condições climáticas, em específico a precipitação diária, num trecho selecionado da Rodovia BR- 376 (Paraná, Brasil). Uma análise de correspondência múltipla (ACM) foi aplicada (software Statigraphics) para determinar a relação existente entre as características dos acidentes e a precipitação. A ACM permitiu a criação de um mapa perceptual, agrupando as variáveis consideradas semelhantes de acordo com o método, o qual evidenciou que a intensidade da chuva não foi um fator significativo para alterar as características dos acidentes. Entretanto, a ocorrência de precipitação mostrou-se como uma circunstância condicionante. Com respeito à segurança da rodovia, a pesquisa indica aplicações práticas que podem ser aplicadas pelas agências de tráfego, como a implementação de sinalização de tráfego e educacional em pontos específicos da rodovia.

Victims of road accidents with serious injuries and dependence on some individual, climatic and infrastructure factors on federal highways in Brazil

Road or urban traffic accidents in Brazil have a large presence in external causes of mortality. The main goal of this study is to discover significant factors in the incidence of accidents on Brazilian highways based on a database with information on each person injured on federal highways in Brazil reported by the Federal Highway Police. Some factors are considered in the study as cause of the accident, type of accident, stage of the day, weather condition, highway type, highway facility, age of the victim, gender of the victim and type of vehicle. From the obtained results of chi-square tests and logistic regression models, it was observed statistical dependence (p < 0.05) of the occurrence of injured people with serious injuries and the factors cause of the accident, type of accident, day, highway type and vehicle type. Considering the dead victims, the covariates age, time of day, highway type, highway facility, gender and type of vehicle showed significance (p < 0.05). These results are of great interest for authorities to increase road enforcement, improve highway facilities and target the production of vehicles with better safety standards.

Prediction of the resilient modulus of two tropical subgrade soils considering unsaturated conditions

The resilient modulus (MR) is essential for the understanding of pavement response to climate effects, and to seasonal fluctuations of water content and matric suction. Unfortunately, only few studies have been directed towards the unsaturated resilient behavior of tropical soils and the influence of weathering and degree of laterization. This paper presents a study of the unsaturated resilient behavior of two tropical soils with distinct degrees of laterization, used as subgrades of highways in Brazil. The experimental program involved the measurement of the soil-water characteristic curve (SWCC), and the MR at different water contents and matric suctions. Eight models for MR, taken from the literature, were evaluated, and a new family of equations is proposed. The obtained SWCCs of the lateritic soil presented bimodal behavior, while the non-lateritic soil is unimodal. The bimodal behavior was attributed to clay aggregates produced by the laterization process. The observed relationship between MR and the stress-state variables depended on the degree of laterization. The lateritic subgrade soil showed significantly higher values of MR, but the resilient behavior was more sensitive to the water content when compared to the non-lateritic soil. The analysis of the literature models for MR indicated limitations in the manner how the unsaturated behavior was incorporated, producing adjusted coefficients of determination (Adj. R2) between 0.48 and 0.77. The newly proposed MR model was based on the statistical analyses of seven equations. The final proposed model includes two independent stress-state variable and a third state variable, that accounts for the water content deviation from optimum conditions. Finally, the proposed model was validated using MR data from the literature. The proposed model produced superior results when comparing to the previously proposed equations, resulting in values of Adj. R2 varying between 0.93 and 0.99. The newly proposed model proved to be flexible, being capable of modeling both the lateritic and non-lateritic soils in an accurate manner. These results are expected to offer significant improvements to the Brazilian mechanistic-empirical pavement design guide, and for similar guides in other countries where tropical soils are found.

COMPOSITIONAL STATISTICAL MODELS UNDER A BAYESIAN APPROACH: AN APPLICATION TO TRAFFIC ACCIDENT DATA IN FEDERAL HIGHWAYS IN BRAZIL

ABSTRACT This study considers the use of a composicional statistical model under a Bayesian approach using Markov Chain Monte Carlo simulation methods applied for road traffic victims ocurring in federal roads of Brazil in a specified period of time. The main motivation of the present study is based on a database with information on the injury severity of each person involved in an accident occurred in federal highways in Brazil during a time period ranging from January, 2018 to April, 2019 reported by the federal highway police office of Brazil. Four types of events associated with each injured person (uninjured, minor injury, serious injury and death) are grouped for each state of Brazil in each month characterizing compositional multivariate data. Such kind of data requires specific modeling and inference approaches that differ from the traditional use of multivariate models assuming multivariate normal distributions.The proportion events associated to the accidents (uninjured, minor injuries, serious injuries and deaths) are considered as a sample of vectors of proportions adding to a value one together with some covariates such as pavement conditions in each province, regions of Brazil, months and years that may affect the severity of the injury of each person involved in an accident. From the obtained results, it is observed that the proportions of serious accidents and deaths are affected by some covariates as the different regions of Brazil and years.

Cold Recycled Asphalt Mixture using 100% RAP with Emulsified Asphalt‐Recycling Agent as a New Pavement Base Course

The rehabilitation process of asphalt pavements using the technique of milling and filling can cause several environmental problems due to either the disposal of the milled asphalt mix or the exploration of natural resources. One alternative to mitigate these impacts is to reuse this milled material, known as reclaimed asphalt pavement (RAP), in the construction of new pavement layers. Within the several available techniques to reuse the RAP, cold recycling using an emulsified asphalt‐recycling agent has shown great potential. The aim of this study is to evaluate the application of a cold recycled asphalt mix using 100% RAP with an emulsified asphalt‐recycling agent as a new pavement base course. A trial section was built employing this material as a pavement base course in a heavy traffic highway in Brazil, and its structural behavior was monitored for 12 months using a Falling Weight Deflectometer (FWD) to assess its performance over time. Furthermore, a laboratory‐testing program was performed to evaluate the recycled mixture stiffness and strength through resilient modulus and indirect tensile strength tests. These tests were used to investigate the influence of the storage interval (7, 14, and 28 days) considering the time between mixing and compaction of the mixture. The effect of the curing time after compaction (1, 3, 7, 26, and 56 days) was also assessed. It was verified in laboratory and in the trial section that the stiffness increases with curing time. Furthermore, the backcalculated elastic resilient moduli indicated values in the same order of magnitude to those obtained in the laboratory tests. In addition to the laboratory test findings, it was also observed that the longer the period of storage, the higher the values of stiffness and tensile strength for short periods of curing. This behavior was not verified when longer curing periods were used. In general, the use of cold recycled asphalt mixtures as base course of new pavements proved to be a promising alternative to reuse RAP.