RESUMO
Transport infrastructural strain is a pressuring issue for the urbanised world due to the increasing demand for public transport. Transport operators, planners and policymakers are constantly searching for low-cost solutions to such transport issues. Therefore, it is critical to developing an environmentally sustainable and economically viable efficient traffic network to relieve traffic pressure (i.e., traffic congestion, transport infrastructure investment needs). The objective of this research is to propose a "Soft Traffic Management (STM)" concept to proactively analyse the traffic impact of transport planning strategy before implementation. This study investigates the effectiveness of a STM for easing the traffic pressure by carrying out a pilot research project on the proposed South East Busway extension in Logan City, Australia, by employing a stepwise process consisting of a multi-stage analysis and stakeholder-based modelling approach. The results indicate that the extended busway can significantly relieve traffic congestion. In addition, the proposed strategy has significantly positive impacts on the environment since it aims to reduce air pollution and fuel consumption as well as to improve the safety and efficiency of the whole transport system. This study confirms the effects of STM on improving the use of existing infrastructure more efficiently and deferring future transport infrastructure investments.
Assuntos
Poluição do Ar , Austrália , Cidades , Previsões , Meios de TransporteRESUMO
PURPOSE: To compare the effectiveness, safety, predictability and stability of FemtoLASIK procedure in low to moderate myopia using Femto Visum and Femto LDV Z6 femtosecond laser platforms and to evaluate the effect of these procedures on corneal higher-order aberrations. MATERIAL AND METHODS: Russian femtolaser platform (1 MHz) was used to form the corneal flap in the main group consisting of 98 patients (98 eyes) with mean spherical equivalent (SE) of -3.73±1.42 D. Swiss femtolaser platform (5 MHz) was used in the control group (94 patients, 94 eyes; mean SE -3.81±1.44 D). Excimer laser ablation was performed using the Russian platform (500 Hz) in both groups. All patients underwent complete ophthalmological examination. The follow-up period was 12 months. RESULTS: Twelve month postoperatively, in the '1 MHz' group uncorrected visual acuity (UCVA) of 1.0 or better was achieved in 91.8% of patients, and in the '5 MHz' group - in 90.4% (p>0.05). There were no registered losses of 2 or more lines of best-corrected visual acuity (BCVA) in either group. In the '1 MHz' group, predictability of targeted refraction within ±0.5 D was achieved in 91.8% of patients, within ±1.0 D - in 99.0%; in the '5 MHz' group - in 91.5% and 98.9% of patients, respectively (p>0.05). Root-mean-square (RMS) deviation of corneal higher-order aberrations in the 6-mm optical zone was increased by 0.072 µm (by 1.21 times) and by 0.077 µm (by 1.22 times) in the '1 MHz' and '5 MHz' groups (p>0.05), respectively. CONCLUSION: The FemtoLASIK procedures performed using Russian (1 MHz) and Swiss (5 MHz) femtosecond laser platforms are effective, safe, predictable, have stable postoperative visual and refractive outcomes, and lead to increase in RMS of corneal higher-order aberrations using both platforms in patients with low to moderate myopia. There were no statistically significant differences between the two femtolaser platforms (p>0.05) for all examined parameters.
Assuntos
Miopia , Seguimentos , Humanos , Ceratomileuse Assistida por Excimer Laser In Situ , Lasers de Excimer , Refração Ocular , Federação Russa , Resultado do TratamentoRESUMO
While macroscopic simulations of passenger vehicle traffic within cities are now common practice, the integration of last mile delivery into a macroscopic simulation to evaluate the emissions has seldomly been achieved. In fact, studies focusing solely on last mile delivery generally focus on evaluating the delivery service itself. This ignores the effect the delivery service may have on the traffic flow in cities, and therefore, on the resulting emissions. This study fills this gap by presenting the results of two macroscopic traffic simulations of New York City (NYC) in PTV VISUM: (i) on-demand meal delivery services, where the emissions are evaluated for each OD-Pairs (i.e., each trip) and (ii) on-demand meal delivery services, where the emissions are evaluated for each link of the network (i.e., street). This study highlights the effect on-demand meal delivery has on the travelled distance (i.e., detours), congestion and emissions per km of every vehicle in the network, not just the delivery vehicles.
Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Cidades , Simulação por Computador , Monitoramento Ambiental/métodos , Emissões de Veículos/análiseRESUMO
Air pollution continues to be one of the main issues in urban areas. In addition to air quality plans and emission abatement policies, additional measures for high pollution episodes are needed to avoid exceedances of hourly limit values under unfavourable meteorological conditions such as the Madrid's short-term action NO2 protocol. In December 2016 there was a strong atmospheric stability episode that turned out in generalized high NO2 levels, causing the stage 3 of the NO2 protocol to be triggered for the first time in Madrid (29th December). In addition to other traffic-related measures, this involves access restrictions to the city centre (50% to private cars). We simulated the episode with and without measures under a multi-scale modelling approach. A 1â¯km2 resolution modelling system based on WRF-SMOKE-CMAQ was applied to assess city-wide effects while the Star-CCM+ (RANS CFD model) was used to investigate the effect at street level in a microscale domain in the city centre, focusing on Gran Vía Avenue. Changes in road traffic were simulated with the mesoscale VISUM model, incorporating real flux measurements during those days. The corresponding simulations suggest that the application of the protocol during this particular episode may have prevented concentrations to increase by 24⯵g·m-3 (14% respect to the hypothetical no action scenario) downtown although it may have cause NO2 to slightly increase in the city outskirts due to traffic redistribution. Speed limitation and parking restrictions alone (stages 1 and 2 respectively) have a very limited effect. The microscale simulation provides consistent results but shows an important variability at street level, with reduction above 100⯵g·m-3 in some spots inside Gran Vía. Although further research is needed, these results point out the need to implement short-term action plans and to apply a consistent multi-scale modelling assessment to optimize urban air quality abatement strategies.