TRANSPORTES

Data-driven modeling of urban airspace availability for air mobility operations in the São Paulo Metropolitan Region

2024-01-16T13:51:25-03:00

Urban Air Mobility (UAM) is an emerging form of transportation that is expected to introduce novel flight networks into already busy and complex airspace surrounding major cities and metropolitan regions. This work provides a data-driven approach to modeling the urban airspace availability for emerging UAM operations toward supporting their safe and efficient integration. Using historical flight tracking data, clustering analysis is first performed to learn the current patterns of urban airspace use by conventional traffic and identify the airspace volumes that are least constrained and best accessible for UAM flights. Meteorological data is then incorporated into the machine learning framework to create a probabilistic model of the spatiotemporal distribution of conventional traffic flows. This model enables the prediction of active airport arrival/departure patterns and the resulting airspace availability for UAM given dynamic operational conditions. The data-based approach is demonstrated for the São Paulo metropolitan area, which is the largest in Brazil and a promising market for UAM. It allowed for a high-fidelity characterization of the São Paulo urban airspace use patterns as well as for accurate predictions of the available airspace for UAM, bringing novel insights and capabilities in support of dynamic and efficient urban airspace management.

Análise da prática do excesso de velocidade em vias de trânsito rápido a partir de dados naturalísticos de direção

2023-11-15T07:11:48-03:00

O controle da velocidade constitui-se de um desafio para a gestão urbana orientada à redução de mortes e lesões no trânsito. O objetivo deste artigo foi avaliar a influência de características operacionais na ocorrência do excesso de velocidade nas vias de trânsito rápido de Curitiba (PR). A metodologia foi baseada no uso de dados naturalísticos de direção e na aplicação da regressão logística binária para investigar a relação entre características operacionais das vias (variáveis explicativas) e o excesso de velocidade (variável resposta). O resultado geral indica a prática do excesso de velocidade ao longo de 20,64% do tempo de viagem em fluxo livre. A análise isolada das variáveis explicativas indicou que a presença de radar aumentou a chance de não exceder a velocidade entre 8,16 e 21,09 vezes para as situações de qualquer excesso e acima de 20% do limite, respectivamente. A análise conjunta das variáveis explicativas resultou estatisticamente significativa para a presença de radar e a presença de semáforo, sendo que o primeiro reduziu em 9,55 vezes e o segundo aumentou em aproximadamente 30% a chance de excesso. Este resultado demonstra a importância da fiscalização eletrônica de velocidade como parte da estratégia de gestão da velocidade em áreas urbanas.

Mechanistic-empirical assessment of axle load legal limits on Brazilian roadways

2024-04-16T11:05:24-03:00

This paper presents a comprehensive mechanistic-empirical assessment of axle load legal limits policy on Brazilian roadways, considering the intricate balance between enhanced freight transportation and potential pavement deterioration. Focusing on the prevailing flexible pavements, the study explores factors such as asphalt concrete stiffness, thickness, and axle-load increments, accounting for variations in tire-load and pressure. The analysis reveals complex relationships between these factors and their impact on pavement distress mechanisms, particularly fatigue cracking and rutting. The investigation highlights the substantial influence of axle load legal limits adjustments, even seemingly minor ones, on pavement damage, ride quality, safety, and operational efficiency. A calibrated model for assessing mechanistic-empirical load equivalency factors (LEFs) was developed, offering insights into the disparities between the model and existing empirical equations used in the Brazilian Pavement Design Guide (BPDG). This comparison underscores the potential underestimation of axle load legal limits adjustments in the current approach, emphasizing the importance of informed decision-making in transportation policy. In conclusion, this study provides critical insights for policymakers and engineers while considering axle load policy adjustments. The findings emphasize the significance of accurate engineering considerations to sustainably balance economic growth, road safety, and efficient freight transportation within Brazil’s evolving road network.