RESUMO
Public transport priority systems such as Bus Rapid Transit (BRT) and Buses with High Level of Service (BHLS) are top-rated solutions to mobility in low-income and middle-income cities. There is scientific agreement that the safety performance level of these systems depends on their functional, operational, and infrastructure characteristics. However, there needs to be more evidence on how the different characteristics of bus corridors might influence safety. This paper aims to shed some light on this area by structuring a multivariate negative binomial model comparing crash risk on arterial roads, BRT, and BHLS corridors in Bogotá, Colombia. The analyzed infrastructure includes 712.1 km of arterial roads with standard bus service, 194.1 km of BRT network, and 135.6 km of BHLS network. The study considered crashes from 2015 to 2018 -fatalities, injuries, and property damage only- and 30 operational and infrastructure variables grouped into six classes -exposure, road design, infrastructure, public means of transport, and land use. A multicriteria process was applied for model selection, including the structure and predictive power based on [i] Akaike information criteria, [ii] K-fold cross-validation, and [iii] model parsimony. Relevant findings suggest that in terms of observed and expected accident rates and their relationship with the magnitude of exposure -logarithm of average annual traffic volumes at the peak hour (LOG_AAPHT) and the percentage of motorcycles, cars, buses, and trucks- the greatest risk of fatalities, injuries, and property damage occurs in the BHLS network. BRT network provides lower crash rates in less severe collisions while increasing injuries and fatalities. When comparing the BHLS network and the standard design of arterial roads, BHLS infrastructure, despite increasing mobility benefits, provides the lowest safety performance among the three analyzed networks. Individual factors of the study could also contribute to designing safer roads related to signalized intersection density and curvature. These findings support the unique characteristics and traffic dynamics present in the context of Bogotá that could inform and guide decisions of corresponding authorities in other highly dense urban areas from developing countries.
Assuntos
Acidentes de Trânsito , Planejamento Ambiental , Veículos Automotores , Segurança , Colômbia , Acidentes de Trânsito/estatística & dados numéricos , Acidentes de Trânsito/mortalidade , Acidentes de Trânsito/prevenção & controle , Humanos , Veículos Automotores/estatística & dados numéricos , Segurança/estatística & dados numéricos , Modelos Estatísticos , Análise Multivariada , Cidades , Meios de Transporte/estatística & dados numéricosRESUMO
The TransMilenio (TM) is a transport system. Twenty-year-old TM is a fast, highly efficient, and self-sufficient mode of passenger transport. This work aims to evaluate the effects of changing current TM diesel buses by electricity-powered buses (battery, wire-based), on the PM2.5 concentrations at surface level. Emissions calculations considering combustions and resuspension of TM and Non-TM were performed. A CFD model was implemented to estimate current PM2.5 concentrations at the roadside level, and the CFD results were validated using the statistic parameters: MB, RMSE, r, and IOA. Results from the emission calculations indicate that TM buses (30-50%) are one of the main sources of primary PM2.5 in all the considered urban sites in this study. Non-exhaust emissions from most vehicle categories were also identified as an important source of primary PM2.5 (40% of total emissions). The CFD model reproduced closely the trends and levels of PM2.5 concentrations measured at the roadside level in all the locations. Replacing TM diesel vehicles with electric vehicles reduces PM2.5 concentrations between 10 and 30% according to the CFD results obtained. Higher reductions can be achieved if policies are adopted to control other types of vehicles and non-exhaust emissions since they have a contribution of about 60%. Finally, this study shows that the combined use of emission calculations and advanced near-road dispersion models are useful tools to study and manage air quality in large cities.
Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Colômbia , Eletricidade , Monitoramento Ambiental , Veículos Automotores , Material Particulado/análise , Emissões de Veículos/análiseRESUMO
La gestión del riesgo colectivo, abordada desde una perspectiva de articulación de las acciones individuales con las familias y colectivos, debe mostrar resultados diferenciados permitiendo ver la operacionalización del plan de acciones colectivas con el accionar de las EAPB. Para esto se retoma el concepto de Atención Primaria en Salud (APS) y se articula con los gestores comunitarios los cuales permiten evidenciar los resultados. Objetivo: analizar la gestión del riesgo colectivo en salud por medio de la afectación de los determinantes sociales intermedios en la ciudad de Bogotá entre el año 2017 y 2019. Metodología: estudio de caso sobre la estrategia de gestión del riesgo basada en APS. Para esto, se estructuraron tres fases el estudio : fase I (identificación de riesgos), fase II (análisis de riesgos colectivos) y fase III (intervención centrada en las personas). Resultados: se mencionan las acciones realizadas en una EAPB - Subsidiada que permiten mitigar y/o disminuir la externalidad que representa en los indicadores de morbilidad y mortalidad. Particularmente, la acción del gestor permitió evidenciar cuatro grupos de cohortes: gestantes, niños y niñas menores de 5 años, detección temprana de cáncer cérvico-uterino y enfermedades crónicas. Conclusiones: los gestores de riesgo son un insumo útil como estrategia en APS en la ciudad de Bogotá, debido a que se identificó adecuadamente a la mayoría de la población en riesgo y se canalizó oportunamente a las entidades prestadoras de servicio pudiendo tener resultados beneficiosos para la población.