For nearly 100 years the design of highways has incorporated safety through the application of criteria to each individual design element. Design elements are items like the horizontal curve, vertical curves, the cross-section, clear zone and roadside slopes. As a result, safety is only indirectly addressed since the design elements are developed in isolation without a good understanding on the impact of one element on another. To make matters worse, design elements communicate messages to the driver about the appropriate speed for the highway. Long straight tangent sections encourage drivers to drive faster whereas curved highway segments communicate a lower operating speed. This can lead to inconsistent message to the driver when design elements are not coordinated with each other. A new method is proposed that accounts for the interaction between design elements in such a way that the designer can estimate the frequency and societal cost of motor vehicle crashes. With this estimate of cost, the designer can base design decisions on what would minimize the societal cost of both the infrastructure improvement and safety. This method will allow designers to formulate highway designs that achieve a specific level of safety and communicate consistent information to drivers. This research provides a valuable planning and design tool for practitioners and policy makers alike. It represents an important shift in the highway design paradigm.

A segurança viária está diretamente relacionada, dentre outros fatores, com as características do traçado da via. A dissertação tem como objetivo realizar uma comparação entre dois dos principais modelos de análise de consistência de traçado de rodovias de pista simples bidirecional, ou seja, o método dos critérios de segurança, estabelecido por Lamm et al. (1998), e o proposto pela Fitzpatrick et al. (2000), que foi incorporado no programa IHSDM (Interactive Highway Safety Design Model) pelo módulo DCM (Design Consistency Module), desenvolvido pela FHWA (Federal Highway Administration). São apresentadas as principais características do procedimento estabelecido por cada um dos métodos e os resultados de uma análise comparativa da aplicação de ambos os métodos em um estudo de caso. Nos dois modelos de análise, as equações de previsão de velocidades foram determinadas para as situações de outros países. No estudo de caso relatado na presente dissertação, foram pesquisadas as velocidades praticadas pelos motoristas em três rodovias de pista simples bidirecional, com base nas quais foi possível estabelecer uma equação de previsão de velocidades. Efetuada a comparação dos resultados obtidos no estudo de caso, pode-se verificar que nas curvas com raios de curvatura maior de 100 m, as velocidades praticadas pelos motoristas nas condições das rodovias pesquisadas são semelhantes às velocidades estimadas pela equação de Fitzpatrick (2000), e nas curvas com raios menores de 100 m, as velocidades praticadas estão próximas da equação elaborada por Lamm (1998) na Alemanha. / Highway safety is directly related, amongst other factors, to highway design characteristics. This dissertation compares two of the main existing models of analysis of highway design consistency, which are: the safety criteria method established by Lamm et al. (1998) and the one proposed by Fitzpatrick et al. (2000) incorporated in the Interactive Highway Safety Design Model (IHSDM) by the Design Consistency Module (DCM), developed by the Federal Highway Administration (FHWA). The main characteristics of the process established by each of the methods are presented here along with the results of a comparative analysis of the application of both methods in a case study. Both models apply speed prediction equations based on studies carried out in other countries. In the case study reported in the present dissertation, the speed practiced by drivers in three bidirectional two-lane roads was investigated, yielding results which allowed the development of a speed prediction equation. After comparing the results obtained in the case study, it was verified that on curves with radius of curvature longer than 100m, the speeds practiced by drivers in the conditions of the roads here studied are similar to those predicted by Fitzpatrick\'s (2000) equation. However, on roads whose radius is shorter than 100m, the speeds practiced are closer to those yielded by the equation elaborated by Lamm (1988) in Germany.

Automobile transportation consumes a significant amount of non-reusable energy and emits emissions as by-products of fuel consumption. There has been much progress in the development of vehicle engine technology and alternative fuels to reduce the adverse impact of highway transportation on the environment. However, the research regarding the reduction of the adverse impact through highway design is still in its infancy. Furthermore, highway design manuals/guidebooks do not provide any information on environmentally-friendly designs. The primary objective of this research was to provide the tools and guidelines for a quantitative environmental evaluation in highway design. This research provided the results regarding the quantitative environmental impacts, by means of fuel consumption and emissions, of various highway geometric design conditions on the vertical grades as well as for horizontal and vertical crest curves that could be included in the highway design process. The researcher generated second-by-second speed profiles using the speed prediction models and non-uniform acceleration/deceleration models, and extracted the fuel consumption and emissions rates based on vehicle specific powers and speeds using recently developed motor vehicle emission simulator (MOVES). The generated speed profiles were matched with the extracted rates and aggregated during a trip on the grades and curves. In addition, the researcher conducted the environmental evaluation including a benefit-cost analysis with actual highway geometric data based on the proposed method and processes. The results demonstrated that fuel consumption and emissions could be significantly changed according to highway design conditions on grades and curves. Throughout the analyses, this research provides the guidelines and tools for environmental evaluations related to selected design features as a part of the highway development process. The provided guidelines and tools can reduce the uncertainty associated with the engineering judgment for environmentally-conscious highway design. Finally, this research shows the efficacy of environmentally-friendly design for sustainable (i.e., social, economical, and environmental) transportation.

The purpose of this research is to develop an intersection safety evaluation tool that is capable of assisting designers and planners in the assessment of alternative intersection designs. A conflict exposure model utilizing design hour volumes, intersection configuration and traffic control measures is proposed to achieve this goal. This approach makes use of data typically available for preliminary intersection design. The research goes beyond existing safety performance models which only examine non-directional average daily traffic (ADT) or practices which only account for the geometric and lane configuration of an intersection, such as conflict point analysis. Conflict prediction models are developed for left-turn angle, right-turn, rear end and sideswipe crashes. These models were developed through the analysis of over 1000 simulation scenarios evaluating a full range of approach and turning volumes, lane configurations and traffic control strategies. The quantifiable metrics provided can be used to inform and improve alternative intersection selection processes by differentiating between alternatives based on a surrogate safety performance. This research may be used in screening of intersection alternatives to select the most beneficial design based on objective safety performance metrics.

A segurança viária está diretamente relacionada, dentre outros fatores, com as características do traçado da via. A dissertação tem como objetivo realizar uma comparação entre dois dos principais modelos de análise de consistência de traçado de rodovias de pista simples bidirecional, ou seja, o método dos critérios de segurança, estabelecido por Lamm et al. (1998), e o proposto pela Fitzpatrick et al. (2000), que foi incorporado no programa IHSDM (Interactive Highway Safety Design Model) pelo módulo DCM (Design Consistency Module), desenvolvido pela FHWA (Federal Highway Administration). São apresentadas as principais características do procedimento estabelecido por cada um dos métodos e os resultados de uma análise comparativa da aplicação de ambos os métodos em um estudo de caso. Nos dois modelos de análise, as equações de previsão de velocidades foram determinadas para as situações de outros países. No estudo de caso relatado na presente dissertação, foram pesquisadas as velocidades praticadas pelos motoristas em três rodovias de pista simples bidirecional, com base nas quais foi possível estabelecer uma equação de previsão de velocidades. Efetuada a comparação dos resultados obtidos no estudo de caso, pode-se verificar que nas curvas com raios de curvatura maior de 100 m, as velocidades praticadas pelos motoristas nas condições das rodovias pesquisadas são semelhantes às velocidades estimadas pela equação de Fitzpatrick (2000), e nas curvas com raios menores de 100 m, as velocidades praticadas estão próximas da equação elaborada por Lamm (1998) na Alemanha. / Highway safety is directly related, amongst other factors, to highway design characteristics. This dissertation compares two of the main existing models of analysis of highway design consistency, which are: the safety criteria method established by Lamm et al. (1998) and the one proposed by Fitzpatrick et al. (2000) incorporated in the Interactive Highway Safety Design Model (IHSDM) by the Design Consistency Module (DCM), developed by the Federal Highway Administration (FHWA). The main characteristics of the process established by each of the methods are presented here along with the results of a comparative analysis of the application of both methods in a case study. Both models apply speed prediction equations based on studies carried out in other countries. In the case study reported in the present dissertation, the speed practiced by drivers in three bidirectional two-lane roads was investigated, yielding results which allowed the development of a speed prediction equation. After comparing the results obtained in the case study, it was verified that on curves with radius of curvature longer than 100m, the speeds practiced by drivers in the conditions of the roads here studied are similar to those predicted by Fitzpatrick\'s (2000) equation. However, on roads whose radius is shorter than 100m, the speeds practiced are closer to those yielded by the equation elaborated by Lamm (1988) in Germany.

Although Autonomous Vehicles (AVs) are quickly becoming a reality, there is much that needs to be understood before mainstream commercialization can occur. One critical issue is the interplay between multiple fields of engineering. Whereas the first part of this work is a granular treatment of a specific issue, the second part simultaneously examines numerous fields within the transportation industry. In the surge to understand and develop AVs, researchers tend to study specific subdivisions within the "vehicle engineering umbrella". In particular, mechanical and civil engineers study vehicle dynamics in two different levels of specificity. Mechanical engineers typically investigate small-scale dynamic behavior which applies to a single vehicle, such as vehicle-terrain interactions or the behavior of mechanical components. On the other hand, civil engineers tend to study kinematic behavior: the behavior of platoons as it pertains to large-scale traffic flow. Regardless of the scale of study, each subdivision has a set of performance metrics. Due to the differences among subdivisions, some performance metrics may (unintentionally) compete. Compromises must be made in the design stage to produce a vehicle which caters to an appropriate audience. The first part of this work features two major contributions to bridge the gap between the dynamic and kinematic perspectives. One is the application of Design Envelopes that establishes a framework to balance constraints and assess design tradeoffs arising from each viewpoints. Three Design Envelopes are introduced to reach compromises on a vehicle's velocity, acceleration, and jerk. Another contribution is a methodology to tune the parameters of a car-following model analytically. Current tuning practices require empirically collected traffic count data, which is cumbersome to obtain. Analytically parameterizing car-following models facilitates more robust planning and encompasses both the dynamic and kinematic perspectives. The second contribution utilizes these Design Envelopes to improve a currently-existing speed profile generator. Integrating the Design Envelopes reformulates the existing algorithm as a constrained LQR problem, which enhances ride comfort and maintains dynamic stability for not just one vehicle, but a platoon. Simulations demonstrate that the refined algorithm can reduce the travel time on a specific route by 3-4.4%. More importantly, the simulations demonstrate it is possible to synthesize multiple engineering fields to enhance AV design. The second part of this work features two contributions aimed at revisions to modern-day highway design policies based on the concept of combining microscopic and macroscopic principles. One common belief is that AVs should drive better than the best human drivers, which suggests operating at or close to the vehicle's theoretical handling limits. Operating in this manner requires a thorough understanding of the associated risks, particularly the risks stemming from uncertainty. This is especially pertinent as there are many inherently probabilistic quantities that are conveniently treated as deterministic in vehicle performance simulations, such as the coefficient of friction. This is a questionable practice when operating on the precipice of compromised safety. Thus, the second part of this work probabilistically examines the chance of handling loss given the amount of tire-road friction and driver acceleration. The result is a mathematically rigorous quantification of a safety margin for various road conditions and driver ability levels. Changes to the official US highway design handbook are recommended based on the findings. / Doctor of Philosophy / Autonomous vehicles (AVs) are quickly becoming a reality. In the surge to understand and develop AVs, researchers tend to study specific subdivisions within the vehicle engineering umbrella. In particular, mechanical and civil engineers study vehicle dynamics in two different levels of specificity. Mechanical engineers typically investigate the dynamics of a single vehicle, such as vehicle-terrain interactions or how various mechanical components operate. On the other hand, civil engineers tend to study traffic flow, which involves platoons (large groups of vehicles). Regardless of the scale of study, each subdivision has a set of performance metrics. Due to the differences among subdivisions, some performance metrics may (unintentionally) compete. Compromises must be made in the design stage to produce a vehicle which caters to an appropriate audience. This work features four main contributions. The first contribution is the application of Design Envelopes that establishes a framework to balance constraints arising from the different ways of studying vehicle dynamics. Three Design Envelopes are introduced to reach compromises on various facets of a vehicle's behavior, such as the vehicle's speed. The second contribution utilizes these Design Envelopes to improve a currently-existing speed profile generator. The current speed profile generator determines how to smoothly transition between two speeds (such as needing to decelerate to remain under a speed limit), but the ride may be uncomfortable to passengers. Integrating the Design Envelopes into the algorithm enhances the ride comfort for not just one vehicle, but a platoon. Simulations demonstrate that the refined algorithm can reduce the travel time on a specific route by 3-4.4%. The third contribution examines how horizontal curves on highways are designed, and a revision based on an acceleration-based safety margin is proposed. Finally, the fourth contribution considers important design variables probabilistically to establish a link between a motorist's acceleration and the chance of a tire skidding failure, which can impact the way straightaway road segments are designed to accommodate sudden braking maneuvers. As a whole, this work demonstrates it is possible to synthesize multiple engineering fields to enhance both current and future (full-scale AV implementation) roadway design.

A aquaplanagem é um fenômeno que pode ocasionar riscos de acidentes em pistas rodoviárias e que consiste na perda de aderência entre os pneus de um veículo e a superfície do pavimento, em decorrência da presença de uma película de água com certa espessura que impede o contato entre ambos, situação essa que pode ser gerada em condições de precipitações pluviométricas de intensidades relativamente elevadas. De uma forma geral tal fenômeno é desconsiderado em normas, manuais e especificações para projetos rodoviários, tanto no Brasil como no Exterior. O presente trabalho tem como objetivo básico a proposição de um procedimento metodológico que permita a identificação de trechos de traçados rodoviários nos quais tal fenômeno possa ocorrer, seja na fase de elaboração de projetos, seja no processo de avaliação das condições de segurança de pistas existentes. O procedimento proposto foi estruturado com base na análise dos principais modelos de previsão de risco de aquaplanagem levantados durante a revisão bibliográfica, bem como em uma extensiva análise das principais variáveis que influenciam esse fenômeno. Com o propósito de avaliar a adequabilidade do procedimento proposto foi elaborado um estudo de caso considerando as características geométricas e dados pluviométricos relativos a determinada extensão do Trecho Leste do Rodoanel de São Paulo. Em tal estudo de caso foram apresentadas proposições de soluções alternativas de mitigação de risco para os trechos identificados como locais com possibilidade de ocorrência de aquaplanagem. / Hydroplaning is a phenomenon that can result in hazard risk on highways, its occurrence is defined by an absence of adherence between the tire and the pavement caused by the presence of a water film of a certain depth that hinder the contact between those surfaces, it\'s occurrence is related to high rainfall intensity situations. Usually highway design manuals, standards and criteria don\'t consider the occurrence of this phenomenon, in Brazil or abroad. The present work has the object of proposing a methodological procedure that allows for the identification of highway segments that are subject to hydroplaning, during its design or during the evaluation of its security conditions. The proposed procedure was based on the analysis of the hydroplaning prediction models studied during the bibliography review, as well as in an extensive analysis of the main variables influencing its occurrence. For the evaluation of the proposed procedure, a case study was conducted with the east portion of the \"Rodoanel Mario Covas\" geometric characteristics and pluviometry data. In this study some risk mitigation proposals were evaluated for the extensions on which were identified the possibility of hydroplaning occurrence.

A aquaplanagem é um fenômeno que pode ocasionar riscos de acidentes em pistas rodoviárias e que consiste na perda de aderência entre os pneus de um veículo e a superfície do pavimento, em decorrência da presença de uma película de água com certa espessura que impede o contato entre ambos, situação essa que pode ser gerada em condições de precipitações pluviométricas de intensidades relativamente elevadas. De uma forma geral tal fenômeno é desconsiderado em normas, manuais e especificações para projetos rodoviários, tanto no Brasil como no Exterior. O presente trabalho tem como objetivo básico a proposição de um procedimento metodológico que permita a identificação de trechos de traçados rodoviários nos quais tal fenômeno possa ocorrer, seja na fase de elaboração de projetos, seja no processo de avaliação das condições de segurança de pistas existentes. O procedimento proposto foi estruturado com base na análise dos principais modelos de previsão de risco de aquaplanagem levantados durante a revisão bibliográfica, bem como em uma extensiva análise das principais variáveis que influenciam esse fenômeno. Com o propósito de avaliar a adequabilidade do procedimento proposto foi elaborado um estudo de caso considerando as características geométricas e dados pluviométricos relativos a determinada extensão do Trecho Leste do Rodoanel de São Paulo. Em tal estudo de caso foram apresentadas proposições de soluções alternativas de mitigação de risco para os trechos identificados como locais com possibilidade de ocorrência de aquaplanagem. / Hydroplaning is a phenomenon that can result in hazard risk on highways, its occurrence is defined by an absence of adherence between the tire and the pavement caused by the presence of a water film of a certain depth that hinder the contact between those surfaces, it\'s occurrence is related to high rainfall intensity situations. Usually highway design manuals, standards and criteria don\'t consider the occurrence of this phenomenon, in Brazil or abroad. The present work has the object of proposing a methodological procedure that allows for the identification of highway segments that are subject to hydroplaning, during its design or during the evaluation of its security conditions. The proposed procedure was based on the analysis of the hydroplaning prediction models studied during the bibliography review, as well as in an extensive analysis of the main variables influencing its occurrence. For the evaluation of the proposed procedure, a case study was conducted with the east portion of the \"Rodoanel Mario Covas\" geometric characteristics and pluviometry data. In this study some risk mitigation proposals were evaluated for the extensions on which were identified the possibility of hydroplaning occurrence.

Via, condutor e veículo são os principais componentes de um sistema viário. A segurança viária decorre de como estes agentes se relacionam entre si. Esta relação pode ser avaliada através da velocidade operacional que o condutor aplica em seu veículo segundo a percepção de conforto e segurança repassada pela rodovia. A análise da consistência geométrica é uma ferramenta de análise para rodovias de pista simples que permite identificar o padrão de utilização das mesmas, através de modelos de estimativa da velocidade operacional e de critérios classificatórios. A análise de consistência geométrica vem sendo utilizada como ferramenta para avaliar problemas de projeto e operação de rodovias existentes e em projeto. A Federal Highway Administration – FHWA recomenda a utilização deste tipo de análise para avaliar a segurança viária de rodovias de pista simples. Os modelos utilizados na análise de consistência geométrica estão calibrados para condicionantes culturais do condutor, de veículos e de rodovias dos Estados Unidos. Assim, a aplicação direta do software IHSDM – Interactive Highway Safety Design Model em rodovias de pista simples do Brasil não é recomendada. A presente Tese propõe um método para análise da consistência geométrica de rodovias brasileiras de pista simples. O método utiliza modelos próprios para estimativa da velocidade operacional, critérios de aplicação das taxas de aceleração e desaceleração e propõe um índice para classificação das rodovias por quilômetro e por trecho: o ICG (índice de consistência geométrica). No estudo de caso, 14 trechos rodoviários, totalizando 225 quilômetros, são submetidos à análise pelo método proposto. A classificação obtida é confrontada com quatro índices de acidentes distintos, resultantes de uma base de dados de acidentes de seis anos, com 14.608 ocorrências. O resultado deste confronto apresenta uma correlação entre o índice de consistência geométrica por trecho, proposto, e o índice de acidentes totais e parciais de 0,59. O valor obtido confirma a relação prevista entre a freqüência de acidentes e indicadores de consistência geométrica, verificada pela FHWA, surpreendendo pela sua intensidade. O melhor desempenho do índice proposto é associado a sua composição, contemplando os critérios de segurança I (consistência do projeto) e II (consistência da velocidade operacional) e ao comportamento verificado em condutores brasileiro, menos sensíveis a restrições geométricas. / The highway, the individual users and the vehicle are the main agents of a traffic system. Traffic safety is determined by how these agents interconnect. Such relation may be assessed by the observation of the operational speed the driver uses in the vehicle according to his perception of comfort and safety of the roadways. The design consistency analysis is an assessment tool for rural two-lane highways which allows the identification of their usage patterns by using operational speed estimate models and sorting criteria. The design consistency analysis has been used as a tool to assess project and operation flaws of existing highways and projects to construct new highways. The Federal Highway Administration – FHWA recommends the use of this kind of analysis to assess the traffic safety of rural two-lane highways. The models used for the design consistency analysis are calibrated to the conditional cultural aspects of United States of America’s drivers, vehicles and highways. Therefore, the straight application of IHSDM – Interactive Highway Safety Design Model software in Brazilian rural two-lane highways is not recommended. This doctoral thesis aims at presenting a method of design consistency analysis of Brazilian rural two-lane highways. Such method uses original models for estimating the operational speed, new criteria for application of acceleration vehicle dynamics rate and introduces a new index to classify highways by kilometer and by segment: the ICG or Design Consistency Index. In this case study, 14 roadway segments – of a total of 225 kilometers – were analyzed by the proposed method. The resulting classification was compared to four other accident indexes from a database of 14,608 official records collected in six years. The result of this comparison leads to a correlation between the proposed design consistency index by highways segment and the total and partial accident index of 0.59. The result confirms the foreseen relation between the accident frequency and the design consistency indicators verified by FHWA – and its intensity is astonishing. The best performance of the proposed index is associated to its composition, which involves the safety criteria I (design consistency) and II (operational speed consistency), and to the behavior observed in Brazilian drivers, less sensitive to geometric restrictions.

Via, condutor e veículo são os principais componentes de um sistema viário. A segurança viária decorre de como estes agentes se relacionam entre si. Esta relação pode ser avaliada através da velocidade operacional que o condutor aplica em seu veículo segundo a percepção de conforto e segurança repassada pela rodovia. A análise da consistência geométrica é uma ferramenta de análise para rodovias de pista simples que permite identificar o padrão de utilização das mesmas, através de modelos de estimativa da velocidade operacional e de critérios classificatórios. A análise de consistência geométrica vem sendo utilizada como ferramenta para avaliar problemas de projeto e operação de rodovias existentes e em projeto. A Federal Highway Administration – FHWA recomenda a utilização deste tipo de análise para avaliar a segurança viária de rodovias de pista simples. Os modelos utilizados na análise de consistência geométrica estão calibrados para condicionantes culturais do condutor, de veículos e de rodovias dos Estados Unidos. Assim, a aplicação direta do software IHSDM – Interactive Highway Safety Design Model em rodovias de pista simples do Brasil não é recomendada. A presente Tese propõe um método para análise da consistência geométrica de rodovias brasileiras de pista simples. O método utiliza modelos próprios para estimativa da velocidade operacional, critérios de aplicação das taxas de aceleração e desaceleração e propõe um índice para classificação das rodovias por quilômetro e por trecho: o ICG (índice de consistência geométrica). No estudo de caso, 14 trechos rodoviários, totalizando 225 quilômetros, são submetidos à análise pelo método proposto. A classificação obtida é confrontada com quatro índices de acidentes distintos, resultantes de uma base de dados de acidentes de seis anos, com 14.608 ocorrências. O resultado deste confronto apresenta uma correlação entre o índice de consistência geométrica por trecho, proposto, e o índice de acidentes totais e parciais de 0,59. O valor obtido confirma a relação prevista entre a freqüência de acidentes e indicadores de consistência geométrica, verificada pela FHWA, surpreendendo pela sua intensidade. O melhor desempenho do índice proposto é associado a sua composição, contemplando os critérios de segurança I (consistência do projeto) e II (consistência da velocidade operacional) e ao comportamento verificado em condutores brasileiro, menos sensíveis a restrições geométricas. / The highway, the individual users and the vehicle are the main agents of a traffic system. Traffic safety is determined by how these agents interconnect. Such relation may be assessed by the observation of the operational speed the driver uses in the vehicle according to his perception of comfort and safety of the roadways. The design consistency analysis is an assessment tool for rural two-lane highways which allows the identification of their usage patterns by using operational speed estimate models and sorting criteria. The design consistency analysis has been used as a tool to assess project and operation flaws of existing highways and projects to construct new highways. The Federal Highway Administration – FHWA recommends the use of this kind of analysis to assess the traffic safety of rural two-lane highways. The models used for the design consistency analysis are calibrated to the conditional cultural aspects of United States of America’s drivers, vehicles and highways. Therefore, the straight application of IHSDM – Interactive Highway Safety Design Model software in Brazilian rural two-lane highways is not recommended. This doctoral thesis aims at presenting a method of design consistency analysis of Brazilian rural two-lane highways. Such method uses original models for estimating the operational speed, new criteria for application of acceleration vehicle dynamics rate and introduces a new index to classify highways by kilometer and by segment: the ICG or Design Consistency Index. In this case study, 14 roadway segments – of a total of 225 kilometers – were analyzed by the proposed method. The resulting classification was compared to four other accident indexes from a database of 14,608 official records collected in six years. The result of this comparison leads to a correlation between the proposed design consistency index by highways segment and the total and partial accident index of 0.59. The result confirms the foreseen relation between the accident frequency and the design consistency indicators verified by FHWA – and its intensity is astonishing. The best performance of the proposed index is associated to its composition, which involves the safety criteria I (design consistency) and II (operational speed consistency), and to the behavior observed in Brazilian drivers, less sensitive to geometric restrictions.