scholarly journals Assessing vehicle fuel efficiency using a dense network of CO<sub>2</sub> observations

2021 ◽  
Author(s):  
Helen Fitzmaurice ◽  
Alexander J. Turner ◽  
Jinsol Kim ◽  
Katherine Chan ◽  
Erin R. Delaria ◽  
...  
Keyword(s):  
Air Quality ◽  
Urban Areas ◽  
Local Governments ◽  
Fuel Efficiency ◽  
Vehicle Speed ◽  
Spatial And Temporal Scales ◽  
Fleet Composition ◽  
Transportation Emissions ◽  
Neighborhood Scale ◽  
Vehicle Fuel Efficiency

Abstract. Transportation represents the largest sector of anthropogenic CO2 emissions in urban areas. Timely reductions in urban transportation emissions are critical to reaching climate goals set by international treaties, national policies, and local governments. Transportation emissions also remain one of the largest contributors to both poor air quality (AQ) and to inequities in AQ exposure. As municipal and regional governments create policy targeted at reducing transportation emissions, the ability to evaluate the efficacy of such emission reduction strategies at the spatial and temporal scales of neighborhoods is increasingly important. However, the current state of the art in emissions monitoring does not provide the temporal, sectoral, or spatial resolution necessary to track changes in emissions and provide feedback on the efficacy of such policies at a neighborhood scale. The BErkeley Air Quality and CO2 Network (BEACO2N) has previously been shown to provide constraints on emissions from the vehicle sector in aggregate over a ~1300 km2 multi-city spatial domain. Here, we focus on a 5 km, high volume, stretch of highway in the SF Bay area. We show that inversion of the BEACO2N measurements can be used to understand two factors that affect fuel efficiency: vehicle speed and fleet composition. The CO2 emission rate of the average vehicle (g/vkm) are shown to vary by as much as 27 % at different times of a typical weekday because of changes in vehicle speed and fleet composition. The BEACO2N-derived emissions estimates are consistent to within ~3 % of estimates derived from publicly available measures of vehicle type, number, and speed, providing direct observational support for the accuracy of the Emissions FACtor model (EMFAC) of vehicle fuel efficiency.

Contextual Density and US Automotive CO2 Emissions across the Rural–Urban Continuum

2015 ◽  
Vol 40 (6) ◽  
pp. 590-615 ◽  
Author(s):  
Andrew Perumal ◽  
David Timmons
Keyword(s):  
Urban Areas ◽  
Methodological Approach ◽  
Fuel Efficiency ◽  
Geographical Information ◽  
Population Densities ◽  
Spatial Differences ◽  
Using Data ◽  
Household Travel ◽  
Vehicle Fuel Efficiency ◽  
National Household Travel Survey

Using data from the 2009 National Household Travel Survey, we quantify the effects of settlement patterns on individual driving habits and the resulting automotive carbon dioxide (CO2) emissions. We employ CO2 emissions to capture this impact accurately, as it reflects both vehicle miles traveled and any spatial differences in vehicle fuel efficiency choices. While previous studies have compared automotive travel in urban and suburban areas, our approach characterizes emissions across the entire US rural–urban gradient, focusing on the effects of population density. Rather than using categorical measures of contextual density (city, suburb, town, etc.), we use a geographical information system to calculate continuous measures of contextual density, that is, density at different proximities to households. These measures of contextual density allow us to model travel effects induced by the gravitational pull of the population densities of urban cores. Further, our methodological approach frames location choice as an endogenous treatment effect; that is, residential locations are not randomly assigned across our sample and significantly alter driving behavior. We find that individuals living in urban cores generate the lowest per capita automotive CO2 emissions, due to close proximities of population concentrations. Rather than attracting individuals who would likely have low CO2 emissions anyway, urban location apparently mitigates the emissions of people who would otherwise tend to have high automotive CO2 emissions. We find larger elasticities with respect to density than previous studies and also find that the attractive forces of population densities affect driving patterns at distances up to sixty-one kilometers outside of urban areas.

scholarly journals Assessing the Impact of Vehicle Speed Limits and Fleet Composition on Air Quality Near a School

2019 ◽  
Vol 16 (1) ◽  
pp. 149 ◽  
Author(s):  
Jiayi Tang ◽  
Aonghus McNabola ◽  
Bruce Misstear ◽  
Francesco Pilla ◽  
Md Saniul Alam
Keyword(s):  
Air Quality ◽  
Urban Air Pollution ◽  
Vehicle Speed ◽  
Traffic Emission ◽  
Speed Limits ◽  
School Based ◽  
Pollutant Concentrations ◽  
Fleet Composition ◽  
The Impact ◽  
Background Air

Traffic is a major source of urban air pollution that affects health, especially among children. As lower speed limits are commonly applied near schools in many cities, and different governments have different policies on vehicle fleet composition, this research estimated how different speed limits and fleet emissions affect air quality near a primary school. Based on data of traffic, weather, and background air quality records in Dublin from 2013, traffic, emission, and dispersion models were developed to assess the impact of different speed limits and fleet composition changes against current conditions. Outside the school, hypothetical speed limit changes from 30 km/h to 50 km/h could reduce the concentration of NO2 and PM10 by 3% and 2%; shifts in the fleet from diesel to petrol vehicles could reduce these pollutants by 4% and 3% but would increase the traffic-induced concentrations of CO and Benzene by 63% and 35%. These changes had significantly larger impacts on air quality on streets with higher pollutant concentrations. Findings suggest that both road safety and air quality should be considered when determining speed limits. Furthermore, fleet composition has different impacts on different pollutants and there are no clear benefits associated with incentivising either diesel or petrol engine vehicles.

scholarly journals Sensing the Environmental Neighborhoods

2021 ◽  
pp. 124-133
Author(s):  
Maider Llaguno-Munitxa ◽  
Elie Bou-Zeid
Keyword(s):  
Air Quality ◽  
Urban Areas ◽  
Low Cost ◽  
Fast Response ◽  
Environmental Data ◽  
Design Strategies ◽  
Policy Makers ◽  
Princeton University ◽  
Sensing Technology ◽  
Neighborhood Scale

AbstractGiven the benefits of fine mapping of large urban areas affordably, mobile environmental sensing technologies are becoming increasingly popular to complement the traditional stationary weather and air quality sensing stations. However the reliability and accuracy of low-cost mobile urban technologies is often questioned. This paper presents the design of a fast-response, autonomous and affordable Mobile Urban Sensing Technology (MUST) for the acquisition of high spatial resolution environmental data. Only when accurate neighborhood scale environmental data is affordable and accessible for architects, urban planners and policy makers, can design strategies to enhance urban health be effectively implemented. The results of an experimental air quality sensing campaign developed within Princeton University Campus is presented.

Improving the Protection of Children Against Air Pollution Threats in Romania � The RokidAIR Project Approach and Future Perspectives

2017 ◽  
Vol 68 (4) ◽  
pp. 841-846
Author(s):  
Hai-Ying Liu ◽  
Daniel Dunea ◽  
Mihaela Oprea ◽  
Tom Savu ◽  
Stefania Iordache
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Health Effects ◽  
Urban Areas ◽  
Behavioural Change ◽  
Health Assessment ◽  
Warning System ◽  
Personal Exposure ◽  
Mobile Technologies ◽  
Quality Maps

This paper presents the approach used to develop the information chain required to reach the objectives of the EEA Grants� RokidAIR project in two Romanian cities i.e., Targoviste and Ploiesti. It describes the PM2.5 monitoring infrastructure and architecture to the web-based GIS platform, the early warning system and the decision support system, and finally, the linking of air pollution to health effects in children. In addition, it shows the analysis performance of the designed system to process the collected time series from various data sources using the benzene concentrations monitored in Ploiesti. Moreover, this paper suggests that biomarkers, mobile technologies, and Citizens� Observatories are potential perspectives to improve data coverage by the provision of near-real-time air quality maps, and provide personal exposure and health assessment results, enabling the citizens� engagement and behavioural change. This paper also addresses new fields in nature-based solutions to improve air quality, and studies on air pollution and its mental health effects in the urban areas of Romania.

scholarly journals Non-Newtonian mixed thermo-elastohydrodynamics of hypoid gear pairs

2017 ◽  
Vol 232 (9) ◽  
pp. 1105-1125 ◽  
Author(s):  
M Mohammadpour ◽  
S Theodossiades ◽  
H Rahnejat ◽  
D Dowson
Keyword(s):  
Fuel Efficiency ◽  
Transmission Efficiency ◽  
Operating Conditions ◽  
Predictive Analysis ◽  
Hypoid Gear ◽  
Shear Rates ◽  
Contact Loads ◽  
Harmful Emissions ◽  
Vehicle Fuel Efficiency ◽  
Hypoid Gear Pairs

Transmission efficiency is the main objective in the development of vehicular differential systems, comprising hypoid gear pairs. The overall aim is to contribute to improved vehicle fuel efficiency and thus levels of harmful emissions for modern desired eco-drive axles. Detailed predictive analysis plays an important role in this quest, particularly under realistic operating conditions, comprising high contact loads and shear rates. Under these conditions, the hypoid gear pairs are subject to mixed non-Newtonian thermo-elastohydrodynamic conditions, which is the approach undertaken in this paper. Such an approach for hypoid gear pair has not hitherto been reported in the literature.

scholarly journals Key factors to facilitate locally driven family planning programming: a qualitative analysis of urban stakeholder perspectives in Africa and Asia

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Lisa Mwaikambo ◽  
Sarah Brittingham ◽  
Saori Ohkubo ◽  
Ruwaida Salem ◽  
Denis Joel Sama ◽  
...  
Keyword(s):  
Family Planning ◽  
Health Systems ◽  
Thematic Analysis ◽  
Urban Areas ◽  
Local Governments ◽  
Scale Up ◽  
Analytical Framework ◽  
Essential Elements ◽  
Evidence Based ◽  
Country Ownership

Abstract Background There has been greater recognition of the importance of country ownership in global health and development. However, operationalising country ownership to ensure the scale up and sustainability of proven interventions remains elusive at best. To address this challenge, we undertook a thematic analysis of interviews collected from representatives of local governments, public health systems, and communities in poor urban areas of East Africa, Francophone West Africa, India, and Nigeria, supported by The Challenge Initiative (TCI), aiming to rapidly and sustainably scale up evidence-based reproductive health and family planning solutions. Methods The main objective of this study was to explore critical elements needed for implementing and scaling evidence-based family planning interventions. The research team conducted thematic analysis of 96 stories collected using the Most Significant Change (MSC) technique between July 2018 and September 2019. After generating 55 unique codes, the codes were grouped into related themes, using TCI’s model as a general analytical framework. Results Five key themes emerged: (1) strengthening local capacity and improving broader health systems, (2) shifting mindsets of government and community toward local ownership, (3) institutionalising the interventions within existing government structures, (4) improving data demand and use for better planning of health services, and (5) enhancing coordination of partners. Conclusion While some themes feature more prominently in a particular region than others, taken together they represent what stakeholders perceive to be essential elements for scaling up locally-driven health programmes in urban areas in Africa and Asia.

scholarly journals Analysis of Driving Dynamics Considering Driving Resistances in On-Road Driving

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3408
Author(s):  
Jingeun Song ◽  
Junepyo Cha
Keyword(s):  
Combustion Engine ◽  
Vehicle Speed ◽  
Driving Dynamic ◽  
Engine Emissions ◽  
Engine Load ◽  
Positive Acceleration ◽  
Emission Regulations ◽  
Transportation Emissions ◽  
Light Duty Vehicles ◽  
Dynamic Variables

Internal combustion engine emissions are a serious worldwide problem. To combat this, emission regulations have become stricter with the goal of reducing the proportion of transportation emissions in global air pollution. In addition, the European Commission passed the real driving emissions–light-duty vehicles (RDE-LDV) regulation that evaluates vehicle emissions by driving on real roads. The RDE test is significantly dependent on driving conditions such as traffic or drivers. Thus, the RDE regulation has the means to evaluate driving dynamics such as the vehicle speed per acceleration (v·apos) and the relative positive acceleration (RPA) to determine whether the driving during these tests is normal or abnormal. However, this is not an appropriate way to assess the driving dynamics because the v⋅apos and the RPA do not represent engine load, which is directly related to exhaust emissions. Therefore, in the present study, new driving dynamic variables are proposed. These variables use engine acceleration calculated from wheel force instead of the acceleration calculated from the vehicle speed, so they are proportional to the engine load. In addition, a variable of driving dynamics during braking is calculated using the negative wheel force. This variable can be used to improve the accuracy of the emission assessment by analyzing the braking pattern.

scholarly journals Simulation and measurement of air quality in the traffic congestion area

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Shin Yu ◽  
Chang Tang Chang ◽  
Chih Ming Ma
Keyword(s):  
Air Quality ◽  
Traffic Congestion ◽  
Traffic Management ◽  
Reference Model ◽  
Dispersion Model ◽  
Fluid Model ◽  
Three Dimensional ◽  
Vehicle Speed ◽  
Management Plans ◽  
Dimensional Distribution

AbstractThe traffic congestion in the Hsuehshan tunnel and at the Toucheng interchange has led to traffic-related air pollution with increasing concern. To ensure the authenticity of our simulation, the concentration of the last 150 m in Hsuehshan tunnel was simulated using the computational fluid dynamics fluid model. The air quality at the Toucheng interchange along a 2 km length highway was simulated using the California Line Source Dispersion Model. The differences in air quality between rush hours and normal traffic conditions were also investigated. An unmanned aerial vehicle (UAV) with installed PM2.5 sensors was developed to obtain the three-dimensional distribution of pollutants. On different roads, during the weekend, the concentrations of pollutants such as SOx, CO, NO, and PM2.5 were observed to be in the range of 0.003–0.008, 7.5–15, 1.5–2.5 ppm, and 40–80 μg m− 3, respectively. On weekdays, the vehicle speed and the natural wind were 60 km h− 1 and 2.0 m s− 1, respectively. On weekdays, the SOx, CO, NO, and PM2.5 concentrations were found to be in the range of 0.002–0.003, 3–9, 0.7–1.8 ppm, and 35–50 μg m− 3, respectively. The UAV was used to verify that the PM2.5 concentrations of vertical changes at heights of 9.0, 7.0, 5.0, and 3.0 m were 45–48, 30–35, 25–30, and 50–52 μg m− 3, respectively. In addition, the predicted PM2.5 concentrations were 40–45, 25–30, 45–48, and 45–50 μg m− 3 on weekdays. These results provide a reference model for environmental impact assessments of long tunnels and traffic jam-prone areas. These models and data are useful for transportation planners in the context of creating traffic management plans.

scholarly journals Morpho-Physio-Biochemical Attributes of Roadside Trees as Potential Tools for Biomonitoring of Air Quality and Environmental Health in Urban Areas

Land ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 236
Author(s):  
Ha Na You ◽  
Myeong Ja Kwak ◽  
Sun Mi Je ◽  
Jong Kyu Lee ◽  
Yea Ji Lim ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Environmental Health ◽  
Urban Areas ◽  
Biochemical Parameters ◽  
Lipid Peroxide ◽  
Platanus Occidentalis ◽  
Physiological Variables ◽  
Sources Of Pollution ◽  
Species Specific

Environmental pollution is an important issue in metropolitan areas, and roadside trees are directly affected by various sources of pollution to which they exhibit numerous responses. The aim of the present study was to identify morpho-physio-biochemical attributes of maidenhair tree (Ginkgo biloba L.) and American sycamore (Platanus occidentalis L.) growing under two different air quality conditions (roadside with high air pollution, RH and roadside with low air pollution, RL) and to assess the possibility of using their physiological and biochemical parameters as biomonitoring tools in urban areas. The results showed that the photosynthetic rate, photosynthetic nitrogen-use efficiencies, and photochromic contents were generally low in RH in both G. biloba and P. occidentalis. However, water-use efficiency and leaf temperature showed high values in RH trees. Among biochemical parameters, in G. biloba, the lipid peroxide content was higher in RH than in RL trees, but in P. occidentalis, this content was lower in RH than in RL trees. In both species, physiological activities were low in trees planted in areas with high levels of air pollution, whereas their biochemical and morphological variables showed different responses to air pollution. Thus, we concluded that it is possible to determine species-specific physiological variables affected by regional differences of air pollution in urban areas, and these findings may be helpful for monitoring air quality and environmental health using trees.

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