Engineering › Automotive Engineering

Vehicle emissions and performance

Works Count: 98737

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Description

This cluster of papers focuses on estimating vehicle fuel consumption and emissions, with an emphasis on real-world measurements, driving cycles, eco-driving, and the impact of traffic conditions on emission factors. The research covers a wide range of topics related to vehicle emissions, including NOx and CO2 emissions, fuel consumption, and the influence of road transport on environmental pollution.

Keywords

Fuel Consumption; Eco-Driving; Vehicle Emissions; Real-World Measurements; Traffic Conditions; Driving Cycles; Emission Factors; NOx Emissions; CO2 Emissions; Road Transport

National Ambient Air Quality Standards

1985-01-01

Calvin R. Brunner

Air pollution. Its origin and control

1977-07-01

Kenneth Wark , Cecil Francis Warner , Wayne T. Davis

MANOMETRIC CARBON DETERMINATION

1940-11-01

Donald D. Van Slyke , Jordi Folch

Independent driving pattern factors and their influence on fuel-use and exhaust emission factors

2001-09-01

Eva Ericsson

A review of recent research on green road freight transportation

2014-01-04

Emrah Demir , Tolga Bektaş , Gilbert Laporte

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Transport and climate change: a review

2007-02-13

Lee Chapman

The ARTEMIS European driving cycles for measuring car pollutant emissions

2004-07-22

Michel André

The pollutant emissions from diesel-engine vehicles and exhaust aftertreatment systems

2014-06-10

İbrahim Aslan Reşitoğlu , Kemal Altınışık , Ali Keskin

Diesel engines have high efficiency, durability, and reliability together with their low-operating cost. These important features make them the most preferred engines especially for heavy-duty vehicles. The interest in diesel … Diesel engines have high efficiency, durability, and reliability together with their low-operating cost. These important features make them the most preferred engines especially for heavy-duty vehicles. The interest in diesel engines has risen substantially day by day. In addition to the widespread use of these engines with many advantages, they play an important role in environmental pollution problems worldwide. Diesel engines are considered as one of the largest contributors to environmental pollution caused by exhaust emissions, and they are responsible for several health problems as well. Many policies have been imposed worldwide in recent years to reduce negative effects of diesel engine emissions on human health and environment. Many researches have been carried out on both diesel exhaust pollutant emissions and aftertreatment emission control technologies. In this paper, the emissions from diesel engines and their control systems are reviewed. The four main pollutant emissions from diesel engines (carbon monoxide-CO, hydrocarbons-HC, particulate matter-PM and nitrogen oxides-NOx) and control systems for these emissions (diesel oxidation catalyst, diesel particulate filter and selective catalytic reduction) are discussed. Each type of emissions and control systems is comprehensively examined. At the same time, the legal restrictions on exhaust-gas emissions around the world and the effects of exhaust-gas emissions on human health and environment are explained in this study.

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Development of Ozone Reactivity Scales for Volatile Organic Compounds

1994-07-01

William Carter

Abstract This paper discusses methods for ranking photochemical ozone formation reactivities of volatile organic compounds (VOCs). Photochemical mechanisms for the atmospheric reactions of 118 VOCs were used to calculate their … Abstract This paper discusses methods for ranking photochemical ozone formation reactivities of volatile organic compounds (VOCs). Photochemical mechanisms for the atmospheric reactions of 118 VOCs were used to calculate their effects on ozone formation under various NOx conditions in model scenarios representing 39 different urban areas. Their effects on ozone were used to derive 18 different ozone reactivity scales, one of which is the Maximum Incremental Reactivity (MIR) scale used in the new California Low Emission Vehicle and Clean Fuel Regulations. These scales are based on three different methods for quantifying ozone impacts and on six different approaches for dealing with the dependencies of reactivity on NOx. The predictions of the scales are compared, the reasons for their similarities and differences are discussed, and the sensitivities of the scales to NOx and other scenario conditions are examined. Scales based on peak ozone levels were highly dependent on NOx, but those based on integrated ozone were less sensitive to NOx and tended to be similar to the MIR scale. It is concluded that the MIR scale or one based on integrated ozone is appropriate for applications requiring use of a single reactivity scale.

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Measurement of Emissions from Air Pollution Sources. 2. C1 through C30 Organic Compounds from Medium Duty Diesel Trucks

1999-04-13

James J. Schauer , Michael J. Kleeman , Glen R. Cass +1 more

Gas- and particle-phase tailpipe emissions from late-model medium duty diesel trucks are quantified using a two-stage dilution source sampling system. The diesel trucks are driven through the hot-start Federal Test … Gas- and particle-phase tailpipe emissions from late-model medium duty diesel trucks are quantified using a two-stage dilution source sampling system. The diesel trucks are driven through the hot-start Federal Test Procedure (FTP) urban driving cycle on a transient chassis dynamometer. Emission rates of 52 gas-phase volatile hydrocarbons, 67 semivolatile and 28 particle-phase organic compounds, and 26 carbonyls are quantified along with fine particle mass and chemical composition. When all C1−C13 carbonyls are combined, they account for 60% of the gas-phase organic compound mass emissions. Fine particulate matter emission rates and chemical composition are quantified simultaneously by two methods: a denuder/filter/PUF sampler and a traditional filter sampler. Both sampling techniques yield the same elemental carbon emission rate of 56 mg km-1 driven, but the particulate organic carbon emission rate determined by the denuder-based sampling technique is found to be 35% lower than the organic carbon mass collected by the traditional filter-based sampling technique due to a positive vapor-phase sorption artifact that affects the traditional filter sampling technique. The distribution of organic compounds in the diesel fuel used in this study is compared to the distribution of these compounds in the vehicle exhaust. Significant enrichment in the ratio of unsubstituted polycyclic aromatic hydrocarbons (PAH) to their methyl- and dimethyl-substituted homologues is observed in the tailpipe emissions relative to the fuel. Isoprenoids and tricyclic terpanes are quantified in the semivolatile organics emitted from diesel vehicles. When used in conjunction with data on the hopanes, steranes, and elemental carbon emitted, the isoprenoids and the tricyclic terpanes may help trace the presence of diesel exhaust in atmospheric samples.

Brake Wear Particulate Matter Emissions

2000-09-16

Bhagwan D. Garg , Steven H. Cadle , Patricia A. Mulawa +3 more

Current particulate matter (PM) emission factor models estimate brake wear particulate matter emission rates using data derived from asbestos brakes. However, most brake pads are now produced from nonasbestos materials. … Current particulate matter (PM) emission factor models estimate brake wear particulate matter emission rates using data derived from asbestos brakes. However, most brake pads are now produced from nonasbestos materials. Little work has been performed on emissions from brakes using these materials. Therefore, a brake wear study was performed using seven brake pad formulations that were in high volume use in 1998. Included were semi-metallic brakes, brakes using potassium titanate fibers, and brakes using aramid fibers. Brakes were tested on a brake dynamometer under four wear conditions. On average, 35% of the brake pad mass loss was emitted as airborne PM. The observed wear rates correspond to vehicle emission rates of 5.1−14.1 mg/mi. On average, 86 and 63% of the airborne PM was smaller than 10 μm in diameter (PM10) or 2.5 μm in diameter (PM2.5), respectively. The large number of particles observed in some wear tests was attributed to condensation, a process that is highly dependent on dilution condition. Analysis of airborne PM showed very few inhalable fibers. On average, 18% of the airborne PM was carbonaceous material. Elemental analysis indicated that metallic species together with silicon, phosphorus, sulfur, and chlorine accounted for most of the remaining mass. Estimates of brake wear PM10 and PM2.5 emission rates from light-duty vehicles are made from brake dynanometer wear tests.

Sources of fine organic aerosol. 2. Noncatalyst and catalyst-equipped automobiles and heavy-duty diesel trucks

1993-04-01

Wolfgang F. Rogge , Lynn M. Hildemann , Monica A. Mazurek +2 more

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSources of fine organic aerosol. 2. Noncatalyst and catalyst-equipped automobiles and heavy-duty diesel trucksWolfgang F. Rogge, Lynn M. Hildemann, Monica A. Mazurek, Glen R. Cass, and Bernd … ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSources of fine organic aerosol. 2. Noncatalyst and catalyst-equipped automobiles and heavy-duty diesel trucksWolfgang F. Rogge, Lynn M. Hildemann, Monica A. Mazurek, Glen R. Cass, and Bernd R. T. SimoneitCite this: Environ. Sci. Technol. 1993, 27, 4, 636–651Publication Date (Print):April 1, 1993Publication History Published online1 May 2002Published inissue 1 April 1993https://pubs.acs.org/doi/10.1021/es00041a007https://doi.org/10.1021/es00041a007research-articleACS PublicationsRequest reuse permissionsArticle Views2744Altmetric-Citations1126LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

On-Road Emissions of Particulate Polycyclic Aromatic Hydrocarbons and Black Carbon from Gasoline and Diesel Vehicles

1998-01-15

Antonio H. Miguel , Thomas W. Kirchstetter , Robert A. Harley +1 more

Motor vehicles are a significant source of fine carbonaceous particle emissions. Fuels have been reformulated and vehicle technologies have advanced, so an updated assessment of vehicular emissions is needed. Gas- … Motor vehicles are a significant source of fine carbonaceous particle emissions. Fuels have been reformulated and vehicle technologies have advanced, so an updated assessment of vehicular emissions is needed. Gas- and particle-phase pollutant concentrations were measured in the Caldecott Tunnel in the San Francisco Bay Area during the summer of 1996. Separate samples were collected for uphill traffic in two tunnel bores: one bore was influenced by heavy-duty diesel truck emissions; a second bore was reserved for light-duty vehicles. Fine particle black carbon and PAH concentrations were normalized to fuel consumption to compute emission factors. Light-duty vehicles and heavy-duty diesel trucks emitted, respectively, 30 ± 2 and 1440 ± 160 mg of fine black carbon particles per kg of fuel burned. Diesel trucks were the major source of lighter PAH, whereas light-duty gasoline vehicles were the dominant source of higher molecular weight PAH such as benzo[a]pyrene and dibenz[a,h]anthracene. Size-resolved measurements of particulate PAH showed significant fractions of diesel-derived PAH to be present in both the ultrafine size mode (<0.12 μm) and the ac cumulation mode (0.12−2 μm). In contrast, gasoline engine-derived PAH emissions were found almost entirely in the ultrafine mode.

The Pollution-Routing Problem

2011-03-13

Tolga Bektaş , Gilbert Laporte

Chemical characterization of particulate emissions from diesel engines: A review

2007-08-23

M. Matti Maricq

PM2.5 chemical source profiles for vehicle exhaust, vegetative burning, geological material, and coal burning in Northwestern Colorado during 1995

2001-06-01

John G. Watson , Judith C. Chow , James E. Houck

Size and Composition Distribution of Fine Particulate Matter Emitted from Motor Vehicles

2000-02-19

Michael J. Kleeman , James J. Schauer , Glen R. Cass

A dilution source sampling system is augmented to measure the size-distributed chemical composition of fine particle emissions from motor vehicles. Measurements are made using an optical particle counter (OPC), a … A dilution source sampling system is augmented to measure the size-distributed chemical composition of fine particle emissions from motor vehicles. Measurements are made using an optical particle counter (OPC), a differential mobility analyzer (DMA)/condensation nucleus counter (CNC) combination, and a pair of microorifice uniform deposit impactors (MOUDIs). The sources tested with this system include catalyst-equipped gasoline-powered light-duty vehicles, noncatalyst gasoline-powered light-duty vehicles, and medium-duty diesel trucks. Chemical composition analysis demonstrates that particles emitted from the gasoline-powered vehicles tested are largely composed of organic compounds while particles emitted from diesel engines contain roughly equal amounts of organic compounds and elemental carbon. The particle mass distributions from all mobile sources tested have a single mode that peaks at approximately 0.1−0.2 μm particle diameter. Of the two diesel vehicles tested, the vehicle with the lowest fine particle emissions rate released the largest number of ultrafine particles, a finding similar to that of Bagley et al. (Characterization of fuel and aftertreatment device effects on diesel emissions; Technical Report 76; Health Effects Institute: Cambridge, MA, 1996). Particle size distribution measurements taken throughout the FTP urban driving cycle used to test all of the vehicles described in this paper reveal that particulate mass emission rates and particulate size distributions from the vehicles tested here are similar during the cold start and hot start segments of the driving cycle.

Measurement of Emissions from Air Pollution Sources. 5. C1−C32Organic Compounds from Gasoline-Powered Motor Vehicles

2002-02-14

James J. Schauer , Michael J. Kleeman , Glen R. Cass +1 more

Gas- and particle-phase organic compounds present in the tailpipe emissions from an in-use fleet of gasoline-powered automobiles and light-duty trucks were quantified using a two-stage dilution source sampling system. The … Gas- and particle-phase organic compounds present in the tailpipe emissions from an in-use fleet of gasoline-powered automobiles and light-duty trucks were quantified using a two-stage dilution source sampling system. The vehicles were driven through the cold-start Federal Test Procedure (FTP) urban driving cycle on a transient dynamometer. Emission rates of 66 volatile hydrocarbons, 96 semi-volatile and particle-phase organic compounds, 27 carbonyls, and fine particle mass and chemical composition were quantified. Six isoprenoids and two tricyclic terpanes, which are quantified using new source sampling techniques for semi-volatile organic compounds, have been identified as potential tracers for gasoline-powered motor vehicle emissions. A composite of the commercially distributed California Phase II Reformulated Gasoline used in these tests was analyzed by several analytical methods to quantify the gasoline composition, including some organic compounds that are found in the atmosphere as semi-volatile and particle-phase organic compounds. These results allow a direct comparison of the semi-volatile and particle-phase organic compound emissions from gasoline-powered motor vehicles to the gasoline burned by these vehicles. The distribution of n-alkanes and isoprenoids emitted from the catalyst-equipped gasoline-powered vehicles is the same as the distribution of these compounds found in the gasoline used, whereas the distribution of these compounds in the emissions from the noncatalyst vehicles is very different from the distribution in the fuel. In contrast, the distribution of the polycyclic aromatic hydrocarbons and their methylated homologues in the gasoline is significantly different from the distribution of the PAH in the tailpipe emissions from both types of vehicles.

Road vehicle emission factors development: A review

2013-01-20

Vicente Franco , Marina Kousoulidou , Marilena Muntean +3 more

Sources and properties of non-exhaust particulate matter from road traffic: A review

2008-07-17

A. Thorpe , Roy M. Harrison

Physical characterization of particulate emissions from diesel engines: a review

2005-01-15

H. Burtscher

Energy and emissions impacts of a freeway-based dynamic eco-driving system

2009-03-06

Matthew Barth , Kanok Boriboonsomsin

Characterization of Polycyclic Aromatic Hydrocarbons in Motor Vehicle Fuels and Exhaust Emissions

1999-08-13

Linsey C. Marr , Thomas W. Kirchstetter , Robert A. Harley +3 more

Motor vehicles are a significant source of polycyclic aromatic hydrocarbon (PAH) emissions. Improved understanding of the relationship between fuel composition and PAH emissions is needed to determine whether fuel reformulation … Motor vehicles are a significant source of polycyclic aromatic hydrocarbon (PAH) emissions. Improved understanding of the relationship between fuel composition and PAH emissions is needed to determine whether fuel reformulation is a viable approach for reducing PAH emissions. PAH concentrations were quantified in gasoline and diesel fuel samples collected in summer 1997 in northern California. Naphthalene was the predominant PAH in both fuels, with concentrations of up to 2600 mg L-1 in gasoline and 1600 mg L-1 in diesel fuel. Particle-phase PAH size distributions and exhaust emission factors were measured in two bores of a roadway tunnel. Emission factors were determined separately for light-duty vehicles and for heavy-duty diesel trucks, based on measurements of PAHs, CO, and CO2. Particle-phase emission factors, expressed per unit mass of fuel burned, ranged up to 21 μg kg-1 for benzo[ghi]perylene for light-duty vehicles and up to ∼1000 μg kg-1 for pyrene for heavy-duty diesel vehicles. Light-duty vehicles were found to be a significant source of heavier (four- and five-ring) PAHs, whereas heavy-duty diesel engines were the dominant source of three-ring PAHs, such as fluoranthene and pyrene. While no correlation between heavy-duty diesel truck PAH emission factors and PAH concentrations in diesel fuel was found, light-duty vehicle PAH emission factors were found to be correlated with PAH concentrations in gasoline, suggesting that gasoline reformulation may be effective in reducing PAH emissions from motor vehicles.

Investigations of emissions and heterogeneous formation of HONO in a road traffic tunnel

2001-07-01

R. Kurtenbach , K. Becker , Jewel A. Gomes +7 more

Chase Studies of Particulate Emissions from in-use New York City Vehicles

2004-06-01

Manjula R. Canagaratna , John T. Jayne , D. Asher Ghertner +7 more

Emissions from motor vehicles are a significant source of fine particulate matter (PM) and gaseous pollutants in urban environments. Few studies have characterized both gaseous and PM emissions from individual … Emissions from motor vehicles are a significant source of fine particulate matter (PM) and gaseous pollutants in urban environments. Few studies have characterized both gaseous and PM emissions from individual in-use vehicles under real-world driving conditions. Here we describe chase vehicle studies in which on-road emissions from individual vehicles were measured in real time within seconds of their emission. This work uses an Aerodyne aerosol mass spectrometer (AMS) to provide size-resolved and chemically resolved characterization of the nonrefractory portion of the emitted PM; refractory materials such as elemental carbon (EC) were not measured in this study. The AMS, together with other gas-phase and particle instrumentation, was deployed on the Aerodyne Research Inc. (ARI) mobile laboratory, which was used to "chase" the target vehicles. Tailpipe emission indices of the targeted vehicles were obtained by referencing the measured nonrefractory particulate mass loading to the instantaneous CO2 measured simultaneously in the plume. During these studies, nonrefractory PM1.0 (NRPM1) emission indices for a representative fraction of the New York City Metropolitan Transit Authority (MTA) bus fleet were determined. Diesel bus emissions ranged from 0.10 g NRPM1/kg fuel to 0.23 g NRPM1/kg, depending on the type of engine used by the bus. The average NRPM1 emission index of diesel-powered buses using Continuously Regenerating Technology (CRT™) trap systems was 0.052 g NRPM1/kg fuel. Buses fueled by compressed natural gas (CNG) had an average emission index of 0.034 g NRPM1/kg Fuel. The mass spectra of the nonrefractory diesel aerosol components measured by the AMS were dominated by lubricating oil spectral signatures. Mass-weighted size distributions of the particles in fresh diesel exhaust plumes peak at vacuum aerodynamic diameters around 90 nm with a typical full width at half maximum of 60 nm.

Effect of ethanol–unleaded gasoline blends on engine performance and exhaust emission

2003-01-17

M. Al-Hasan

Environmental assessment of passenger transportation should include infrastructure and supply chains

2009-04-01

Mikhail Chester , Arpad Horvath

To appropriately mitigate environmental impacts from transportation, it is necessary for decision makers to consider the life-cycle energy use and emissions. Most current decision-making relies on analysis at the tailpipe, … To appropriately mitigate environmental impacts from transportation, it is necessary for decision makers to consider the life-cycle energy use and emissions. Most current decision-making relies on analysis at the tailpipe, ignoring vehicle production, infrastructure provision, and fuel production required for support. We present results of a comprehensive life-cycle energy, greenhouse gas emissions, and selected criteria air pollutant emissions inventory for automobiles, buses, trains, and airplanes in the US, including vehicles, infrastructure, fuel production, and supply chains. We find that total life-cycle energy inputs and greenhouse gas emissions contribute an additional 63% for onroad, 155% for rail, and 31% for air systems over vehicle tailpipe operation. Inventorying criteria air pollutants shows that vehicle non-operational components often dominate total emissions. Life-cycle criteria air pollutant emissions are between 1.1 and 800 times larger than vehicle operation. Ranges in passenger occupancy can easily change the relative performance of modes.

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Real-World Carbon Dioxide Impacts of Traffic Congestion

2008-01-01

Matthew Barth , Kanok Boriboonsomsin

Transportation plays a significant role in carbon dioxide (CO 2 ) emissions, accounting for approximately a third of the U.S. inventory. To reduce CO 2 emissions in the future, transportation … Transportation plays a significant role in carbon dioxide (CO 2 ) emissions, accounting for approximately a third of the U.S. inventory. To reduce CO 2 emissions in the future, transportation policy makers are planning on making vehicles more efficient and increasing the use of carbon-neutral alternative fuels. In addition, CO 2 emissions can be lowered by improving traffic operations, specifically through the reduction of traffic congestion. Traffic congestion and its impact on CO 2 emissions were examined by using detailed energy and emission models, and they were linked to real-world driving patterns and traffic conditions. With typical traffic conditions in Southern California as an example, it was found that CO 2 emissions could be reduced by up to almost 20% through three different strategies: congestion mitigation strategies that reduce severe congestion, allowing traffic to flow at better speeds; speed management techniques that reduce excessively high free-flow speeds to more moderate conditions; and shock wave suppression techniques that eliminate the acceleration and deceleration events associated with the stop-and-go traffic that exists during congested conditions.

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Estimating Vehicle Fuel Consumption and Emissions based on Instantaneous Speed and Acceleration Levels

2002-03-01

Kyoungho Ahn , Hesham Rakha , Antonio Trani +1 more

Several hybrid regression models that predict hot stabilized vehicle fuel consumption and emission rates for light-duty vehicles and light-duty trucks are presented in this paper. Key input variables to these … Several hybrid regression models that predict hot stabilized vehicle fuel consumption and emission rates for light-duty vehicles and light-duty trucks are presented in this paper. Key input variables to these models are instantaneous vehicle speed and acceleration measurements. The energy and emission models described in this paper utilize data collected at the Oak Ridge National Laboratory (ORNL) that included fuel consumption and emission rate measurements (CO, HC, and NOx) for five light-duty vehicles and three light-duty trucks as a function of the vehicle's instantaneous speed and acceleration levels. The fuel consumption and emission models are found to be highly accurate as compared to the ORNL data, with coefficients of determination ranging from 0.92 to 0.99. Given that the models utilize the vehicle's instantaneous speed and acceleration levels as independent variables, these models are capable of evaluating the environmental impacts of operational-level projects including intelligent transportation systems. The models developed in this study have been incorporated within the INTEGRATION microscopic traffic simulation model to further demonstrate their application and relevance to the transportation profession. Furthermore, these models have been utilized in conjunction with global positioning system speed measurements to evaluate the energy and environmental impacts of operational-level projects in the field.

Help or hindrance? The travel, energy and carbon impacts of highly automated vehicles

2016-02-26

Zia Wadud , Don MacKenzie , Paul Leiby

Experts predict that new automobiles will be capable of driving themselves under limited conditions within 5–10 years, and under most conditions within 10–20 years. Automation may affect road vehicle energy … Experts predict that new automobiles will be capable of driving themselves under limited conditions within 5–10 years, and under most conditions within 10–20 years. Automation may affect road vehicle energy consumption and greenhouse gas (GHG) emissions in a host of ways, positive and negative, by causing changes in travel demand, vehicle design, vehicle operating profiles, and choices of fuels. In this paper, we identify specific mechanisms through which automation may affect travel and energy demand and resulting GHG emissions and bring them together using a coherent energy decomposition framework. We review the literature for estimates of the energy impacts of each mechanism and, where the literature is lacking, develop our own estimates using engineering and economic analysis. We consider how widely applicable each mechanism is, and quantify the potential impact of each mechanism on a common basis: the percentage change it is expected to cause in total GHG emissions from light-duty or heavy-duty vehicles in the U.S. Our primary focus is travel related energy consumption and emissions, since potential lifecycle impacts are generally smaller in magnitude. We explore the net effects of automation on emissions through several illustrative scenarios, finding that automation might plausibly reduce road transport GHG emissions and energy use by nearly half – or nearly double them – depending on which effects come to dominate. We also find that many potential energy-reduction benefits may be realized through partial automation, while the major energy/emission downside risks appear more likely at full automation. We close by presenting some implications for policymakers and identifying priority areas for further research.

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Power-based electric vehicle energy consumption model: Model development and validation

2016-02-11

Chiara Fiori , Kyoungho Ahn , Hesham Rakha

Air quality guidelines for Europe

1988-01-01

James P. Lodge

On-road vehicle emissions and their control in China: A review and outlook

2016-10-14

Ye Wu , Shaojun Zhang , Jiming Hao +7 more

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Rethinking the ozone problem in urban and regional air pollution

1993-01-01

Fuel consumption and CO 2 emissions from passenger cars in Europe – Laboratory versus real-world emissions

2017-02-21

Georgios Fontaras , Nikiforos Zacharof , Biagio Ciuffo

Official laboratory-measured monitoring data indicate a progressive decline in the average fuel consumption and CO2 emissions of the European passenger car fleet. There is increasing evidence to suggest that officially … Official laboratory-measured monitoring data indicate a progressive decline in the average fuel consumption and CO2 emissions of the European passenger car fleet. There is increasing evidence to suggest that officially reported CO2 values do not reflect the actual performance of the vehicles on the road. A reported difference of 30–40% between official values and real-world estimates was found which has been continuously increasing. This paper reviews the influence of different factors that affect fuel consumption and CO2 emissions on the road and in the laboratory. Factors such as driving behaviour, vehicle configuration and traffic conditions are reconfirmed as highly influential. Neglected factors (e.g. side winds, rain, road grade), which may have significant contributions in fuel consumption in real world driving are identified. The margins of the present certification procedure contribute between 10 and 20% in the gap between the reported values and reality. The latter was estimated to be of the order of 40%, or 47.5 gCO2/km for 2015 average fleet emissions, but could range up to 60% or down to 19% depending on prevailing traffic conditions. The introduction of a new test protocol is expected to bridge about half of the present divergence between laboratory and real world. Finally, substantial literature was found on the topic; however, the lack of common test procedures, analysis tools, and coordinated activity across different countries point out the need for additional research in order to support targeted actions for real world CO2 reduction. Quality checks of the CO2 certification procedure, and the reported values, combined with in-use consumption monitoring could be used to assess the gap on a continuous basis.

Impacts and mitigation of excess diesel-related NOx emissions in 11 major vehicle markets

2017-05-01

Susan C. Anenberg , Joshua Miller , Ray Minjares +7 more

Driving Style Recognition for Intelligent Vehicle Control and Advanced Driver Assistance: A Survey

2017-08-04

Clara Marina Martínez , Mira Heucke , Fei‐Yue Wang +2 more

Driver driving style plays an important role in vehicle energy management as well as driving safety. Furthermore, it is key for advance driver assistance systems development, toward increasing levels of … Driver driving style plays an important role in vehicle energy management as well as driving safety. Furthermore, it is key for advance driver assistance systems development, toward increasing levels of vehicle automation. This fact has motivated numerous research and development efforts on driving style identification and classification. This paper provides a survey on driving style characterization and recognition revising a variety of algorithms, with particular emphasis on machine learning approaches based on current and future trends. Applications of driving style recognition to intelligent vehicle controls are also briefly discussed, including experts' predictions of the future development.

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Aerosol Technology Properties, Behavior, and Measurement of Airborne Particles

2000-09-01

M.L. Laucks

GLOBAL, REGIONAL, AND NATIONAL FOSSIL-FUEL CO2 EMISSIONS

2010-06-08

T. A. Boden , Gregg Marland , R. J. Andres

Rethinking the Ozone Problem in Urban and Regional Air Pollution

1991-01-01

National Research Council

The 100-Car Naturalistic Driving Study: Phase II - Results of the 100-Car Field Experiment

2006-01-01

Tom Dingus , Sheila G. Klauer , V. L. Neale +7 more

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04/02007 Diesel engine exhaust gas recirculation - a review on advanced and novel concepts

2004-07-01

Climate change, 1994: radiative forcing of climate change and an evaluation of the IPCC IS92 emission scenarios

1996-03-01

J. T. Houghton

Foreword Part I. Radiative Forcing of Climate Change: A Summary for Policy Makers: Preface to WGI Report Dedication 1. CO2 and the carbon cycle 2. Other trace gases and atmospheric … Foreword Part I. Radiative Forcing of Climate Change: A Summary for Policy Makers: Preface to WGI Report Dedication 1. CO2 and the carbon cycle 2. Other trace gases and atmospheric chemistry 3. Aerosols 4. Radiative forcing 5. Trace gas radiative fircing indices Part II. An Evaluation of the IPCC IS92 Emission Scenarios: A Summary for Policymakers: Preface to WGIII Report 6. An evaluation of the IPCC IS92 emission scenarios Appendices.

Explainable AI Models for IoT-Based Shaft Power Prediction and Comprehensive Performance Monitoring

2025-06-24

Sotiris Zikas , Katerina Gkirtzou , Ioannis Filippopoulos +5 more | Electronics

This paper presents a comparative analysis of machine learning-based methods for predicting shaft power in ships, a key factor in optimizing ship performance. Accurate shaft power prediction facilitates efficient operations, … This paper presents a comparative analysis of machine learning-based methods for predicting shaft power in ships, a key factor in optimizing ship performance. Accurate shaft power prediction facilitates efficient operations, reducing fuel consumption, emissions, and maintenance costs, aligning with environmental regulations and promoting sustainable maritime practices. The proposed approach evaluates three machine learning methods, analyzing 431 models to determine the most accurate and reliable option for VLCC tankers. XGBoost emerged as the top-performing model, delivering a 13% improvement in accuracy over traditional methods. Using the SHAP framework, key factors influencing shaft power predictions—such as GPS speed, draft, days from dry dock, and wave height—were identified, enhancing model transparency and decision-making clarity. This explainability fosters trust in the use of AI within marine engineering. The results demonstrate that machine learning can optimize maintenance scheduling by reducing unnecessary cleaning procedures, mitigating propulsion system wear, and improving reliability. By using predictive insights, ship operators can achieve better fuel efficiency, lower emissions, and cost savings. The study underscores the potential of explainable machine learning models as transformative tools for ship performance monitoring, supporting greener and more efficient maritime operations.

Investigation of real-world NOx and NH3 emissions from various powertrain vehicles using trip analysis method

2025-06-24

Jun Woo Jeong , Namwook Kim , Kihyung Lee | Fuel

An enhanced pricing model for truck transportation: a case study in Swedish forestry

2025-06-24

Mikael Rönnqvist , Patrik Flisberg , Gunnar Svenson +1 more | International Transactions in Operational Research

Abstract Determining freight rates for heavy trucks involves a detailed analysis of multiple cost factors, including time, distance, fuel, and other operational costs, which collectively contribute to the overall compensation … Abstract Determining freight rates for heavy trucks involves a detailed analysis of multiple cost factors, including time, distance, fuel, and other operational costs, which collectively contribute to the overall compensation for transportation services. However, actual remuneration is based on more simplified agreements. Often, the standard agreement is based on the loaded driving distance. Such agreements provide an accurate description of the average cost over many transports but can be very unfair in compensation on single transports. This paper presents a pricing model for truck transportation that extends traditional models based on distance. The new model includes a measure of cost driving factors along the route, such as hills, road surface, curves, speed limits, intersections, speed changes, long ascents, and other physical difficulties. This measure is extracted from the Calibrated Route Finder, a route selection support system used for roundwood transportation in Sweden. The suggested price model that combines distance and a weighted resistance measure gives a better match between remuneration and full costing of a transport than a model that concentrates only on distance. The suggested model has been tested on a large annual transport data set and detailed and selected transportations evaluated by five large forest companies.

Design and Evaluation of Environmental Value Mechanisms for Green Power Considering Carbon Reductions

2025-06-23

Yan Lu , Mengmeng Zhang , Lei An +3 more | Energies

Under the global context of addressing climate change and actively promoting energy transition, green power has become increasingly vital in the energy structure due to its clean and sustainable advantages. … Under the global context of addressing climate change and actively promoting energy transition, green power has become increasingly vital in the energy structure due to its clean and sustainable advantages. However, the development of green power’s environmental value faces multiple challenges that hinder its marketization. This study first systematically analyzes the current status of developing the environmental value of green power and identifies existing issues. Second, it designs a green power environmental value mechanism and constructs a quantitative model from the perspective of coal-fired power carbon abatement costs, analyzing the emission reduction value of green power in replacing different types of coal-fired power generation. The results show the following: (1) When power generation types are not differentiated, the environmental value exhibits significant seasonal variations. (2) The environmental value for coal-fired units above 300 MW is lower than the overall average, while that of gas-fired units falls between coal-fired units and the average; the environmental value of generating units with a capacity of 300 MW or less is the lowest, followed by that of unconventional coal-fired units. (3) The environmental value calculated based on the marginal carbon abatement cost of coal-fired units, is slightly higher than the tradable green certificate (TGC) price. This study provides policy support for promoting the low-carbon transition of the power sector and facilitating the development of a green power trading market.

Meeting the European Union’s zero-CO2-emissions target for cars in France

2025-06-23

André de Palma , Robin Lindsey , Yannik Riou | Transportation Research Part A Policy and Practice

Análisis de la calidad del aire en la ciudad de Quito pre y post pandemia covid-19

2025-06-23

A. Ordóñez | LATAM Revista Latinoamericana de Ciencias Sociales y Humanidades

La repentina aparición de la Pandemia Covid-19 genero un cambio significativo en la calidad del aire a nivel mundial y en nuestro país no fue la excepción, durante este periodo … La repentina aparición de la Pandemia Covid-19 genero un cambio significativo en la calidad del aire a nivel mundial y en nuestro país no fue la excepción, durante este periodo se presentaron cambios en la calidad del aire en la ciudad de Quito debido a la paralización de diversas actividades de la población decretadas a nivel gubernamental, de esta manera el objetivo de la presente investigación fue determinar la variación del nivel de contaminantes atmosféricos generados en prepandemia, durante la pandemia y post pandemia COVID-19. El método que se utilizó fue el análisis estadístico descriptivo de la base de datos de la Red Metropolitana de Monitoreo Atmosférico de Quito (REMMAQ) de nueve estaciones distribuidas en la ciudad de Quito, en los sectores de Carapungo, Belisario, Guamani, El Camal, Centro, tomando en cuenta la información desde el año 2016 hasta el año 2021. Los resultados obtenidos demostraron que los contaminantes aéreos están debajo de los niveles establecidos por la Normativa Ecuatoriana de Calidad del Aire, a pesar de ello ciertos contaminantes en las zonas de mayor cobertura vehicular como en las estaciones de Camal y Guamani tuvieron valores altos de monóxido de carbono en 2016 con 7,15 mg/m3, mientras que en el año de 2020 descendió hasta 0.53 mg/m3, y en el año 2021 se observó un ligero incremento a 0.60 mg/m3, de igual forma con respecto al ozono existió concentraciones altas de 27.17 μg/m3 en el año de 2020 durante la pandemia, y también con respecto al material particulado hubo concentraciones de 37 μg/m3, visualizándose que en la época de pandemia y postpandemia hubo un cambio notable en la composición del aire debido al Covid-19, demostrando que en la época de pandemia la calidad del aire fue aceptable.

Vehicle-specific power-based emission modeling using unsupervised machine learning techniques

2025-06-23

Chandrashekar Chowdappa , Pritha Chatterjee , Digvijay S. Pawar | Environmental Science and Pollution Research

A Comparative Performance Analysis of Load Cell and Hall-Effect Brake Sensors in Sim Racing

2025-06-21

John M. Joyce , Adam J. Toth , Mark J. Campbell | Sensors

Alongside the general growth in gaming and esports, competitive simulated (sim) racing has specifically surged in popularity in recent years, leading to an increased demand for understanding performance. In recent … Alongside the general growth in gaming and esports, competitive simulated (sim) racing has specifically surged in popularity in recent years, leading to an increased demand for understanding performance. In recent work, braking-related metrics were identified among the key indicators of successful sim racing performance. While load cell sensors currently serve as the industry standard for brake hardware, sensors like the Hall sensor may provide another viable option. No study to date has compared the performance of these braking sensors. The aim of this study was to investigate whether sim racing performance differed when racing using a load cell or Hall brake sensor. Twenty (N = 20) experienced sim racers raced with both the load cell and Hall brake sensors (with load cell behaviour mimicked on the Hall sensor) in a repeated measures design. Paired samples t-tests, Wilcoxon-signed rank tests, and chi-square goodness-of-fit tests were used to test for differences in lap time, driving behaviour metrics, and subjective responses between the two sensors. Results showed that participants achieved faster lap times using the load cell brake sensor (average lap time (p = 0.071); fastest lap time (p = 0.052)) and displayed braking behaviour more aligned with that of a “faster racer”. The differences observed may be potentially attributed to differences in in-game response curves between two brake sensors, which specifically may impact both the initial, and trail braking, phases.

Evaluation of Turkey’s Road-Based Greenhouse Gas Inventory and Future Projections

2025-06-21

Şenay Çeti̇n Doğruparmak , Kazım Onur Demirarslan , Samet Volkan Çavuşoğlu | Applied Sciences

As road traffic in Turkey is a significant source of emissions due to the increasing number of vehicles on the road, the goal of this study is to calculate greenhouse … As road traffic in Turkey is a significant source of emissions due to the increasing number of vehicles on the road, the goal of this study is to calculate greenhouse gas emissions from Turkey’s roads between 2010 and 2020, create an inventory, and estimate possible emissions until 2050. In the study, both greenhouse gases (carbon dioxide (CO2) and nitrous oxide (N2O) and co-emitting air pollutants that indirectly contribute to climate change (ammonia—NH3, nitrogen oxide—NOX, sulfur dioxide—SO2, carbon monoxide—CO, non-methane volatile organic compounds—NMVOC, and particulate matter—PM) were investigated. The study revealed that the total number of vehicles using state roads in Turkey increased by 60% between 2010 and 2020. As a result, emissions of CO2, N2O, NH3, NOX, SO2, CO, NMVOC, and PM increased by 29.6%, 24.2%, 0.5%, 19.9%, 9.9%, 18.2%, 21.5%, and 39.7%, respectively. When emissions were analyzed on a provincial basis, particular attention was drawn to provinces with high levels of urbanization. Based on forecast studies, the total number of vehicles registered for traffic will increase by 105% by 2050. Due to this increase, CO2, N2O, NH3, NOX, SO2, CO, NMVOC, and PM emissions are estimated to increase by 149.17%, 151.78%, 154.39%, 138.95%, 150.97%, 153.09%, 152.09%, and 151.47%, respectively.

Comparative Analysis of Volatile Organic Compound (Voc) Emission Levels Across Different Tillage Operations and Tractor Speeds in Agricultural Practices

2025-06-21

Yakub Bankole , Risikat O Odunukan , Sheriff Lamidi +1 more | International Journal of Latest Technology in Engineering Management & Applied Science

Abstract: This study investigates the emission levels of Volatile Organic Compounds (VOCs) across different tillage operations and tractor speeds in agricultural practices. A field experiment was conducted on a 14.4-hectare … Abstract: This study investigates the emission levels of Volatile Organic Compounds (VOCs) across different tillage operations and tractor speeds in agricultural practices. A field experiment was conducted on a 14.4-hectare farmland using four tractor models (MF new, MF old, NH new, NH old) at three different speeds (15 km/h, 20 km/h, and 24 km/h). The tillage operations included 1st plough, 2nd plough, harrowing, and ridging, with a total of 432 experimental runs. VOC emissions were monitored using a Multireal Pro Handheld Gas Analyzer. The results indicate that the highest VOC emissions occurred at 20 km/h, while at 24 km/h, emissions remained relatively stable across all tillage operations. Among the tillage operations, ridging and 1st ploughing exhibited the highest VOC emissions, while harrowing consistently produced the lowest. These findings emphasize the need for speed regulation and optimized tillage operations to mitigate environmental impact. Future research should explore sustainable tillage practices and emission control technologies to promote environmentally friendly farming.

The Impact of Drag Reduction System Technology on the Performance of Formula One Cars

2025-06-20

Xudong Yang | Applied and Computational Engineering

With the rise of motorsport in recent years, an increasing number of people have turn their attention to this sport. A racing competition is not just a contest of physical … With the rise of motorsport in recent years, an increasing number of people have turn their attention to this sport. A racing competition is not just a contest of physical strength and strategy. More importantly, it involves the continuously innovative racing car technologies. These technologies not only have an impact on motorsport but also play a significant role in the design and innovation of civilian vehicles. The paper, through a method of literature review, explores the impact of the Drag Reduction System on Formula One cars under different conditions. The paper finds that a Drag Reduction System can improve the performance of a racing car. Specifically, it enhances the vehicles straight-line speed by reducing aerodynamic drag, which is particularly crucial in high-speed racing environments where every fraction of a second can make a difference. This improvement in speed not only makes overtaking maneuvers more feasible but also significantly enhances the competitiveness and spectacle of the races. Moreover, the study highlights the strategic importance of DRS in modern Formula One, where its use is governed by specific rules and regulations to ensure fair competition. The findings suggest that while DRS provides a significant performance boost, its effectiveness is contingent upon the drivers skill and the cars overall setup, making it a complex yet essential tool in the arsenal of Formula One teams.

Assessment of NOx concentration levels during periodic technical inspection idle test of SCR-equipped diesel vehicles

2025-06-20

Jacopo Franzetti , Tommaso Selleri , Natalia Fonseca-González +3 more | Environmental Sciences Europe

Microscopic Approach to Analyze the Impact of Lane Change on Road Traffic Noise

2025-06-20

Jae Kwan Lee , Hyoungsoo Kim | Transactions of the Korean Society for Noise and Vibration Engineering

Understanding Transportation Carbon Emission Prediction: Methods, Trends, and Reflections

2025-06-20

Qihua Fan | Applied and Computational Engineering

In the context of the global response to climate change, transportation has received increasing attention as an important source of carbon emissions. The prediction methods for transportation carbon emissions have … In the context of the global response to climate change, transportation has received increasing attention as an important source of carbon emissions. The prediction methods for transportation carbon emissions have continued to develop over the past decade, forming a variety of research paths. This paper reviews the primary research methods on transportation carbon emission prediction in the past decade. Based on the systematic sorting and analysis of the existing literature, this paper classifies the mainstream methods into three categories: traditional mathematical models, simulation methods represented by system dynamics, and intelligent models and their coupled models. This paper systematically summarizes the theoretical foundations, applicable scenarios, and technical characteristics of each type of method, points out the advantages and limitations of different methods. At the same time, this paper proposes that future modeling research can be directed toward model coupling, standardization of the construction process, and other development paths. By comparing the applicability of different prediction methods, the results of this paper can help scholars quickly identify and compare different methods for solving specific research problems.

Influence of Driver Behavior on Fuel Efficiency in Intercity Buses: A Simulation-Based Study of the Yaoundé-Douala Corridor in Cameroon

2025-06-20

Franck Landry Bayi Boumal , Ahmed E. Aboud , Sernin Banza Mwanabute +2 more | Academic Journal of Science and Technology

This study examines the influence of driver behavior on fuel efficiency in intercity buses along Cameroon’s Yaoundé-Douala corridor, a critical route in a fuel-import-dependent transportation sector. Using a combination of … This study examines the influence of driver behavior on fuel efficiency in intercity buses along Cameroon’s Yaoundé-Douala corridor, a critical route in a fuel-import-dependent transportation sector. Using a combination of real-world driving cycle data and GT-SUITE simulations, we analyzed the fuel consumption of a 70-seater Mercedes Benz Actros 2031 bus under varied driving patterns. Findings indicate that aggressive driving behaviors, characterized by delayed shift timing, aggressive acceleration (0.476 m/s² in MD5 cycle) and abrupt braking, increased fuel consumption to 49.8 L/100 km, while smoother driving (0.396 m/s² in SD3 cycle) and proper shift timing achieved 40.6 L/100 km. Gear-shifting patterns and Brake Mean Effective Pressure (BMEP) analysis revealed that optimal engine operation and timely gear transitions significantly enhance efficiency. Despite the route’s infrastructural challenges, such as variable road grades, eco-driving practices offer substantial fuel savings. However, the study’s small driver sample and single-route focus limits generalizability. We recommend eco-driving training, real-time feedback systems, and multi-regional studies to develop tailored interventions for Cameroon’s diverse driving conditions, contributing to economic and environmental sustainability in developing economies.

Comparative Analysis of Data Augmentation Strategies Based on YOLOv12 and MCDM for Sustainable Mobility Safety: Multi-Model Ensemble Approach

2025-06-19

Volkan Tanrıverdi , Kadir Diler Alemdar | Sustainability

The transportation sector is an important stakeholder in greenhouse gas emissions. Sustainable transportation systems come to the forefront against this problem, with the solutions within the scope of micro-mobility especially … The transportation sector is an important stakeholder in greenhouse gas emissions. Sustainable transportation systems come to the forefront against this problem, with the solutions within the scope of micro-mobility especially attracting attention for their environmentally friendly structures. While micro-mobility vehicles reduce the carbon footprint in transportation, their widespread use remains limited due to various security concerns. In this paper, an image processing-based process was carried out on vehicle and safety equipment usage to provide solutions to the security concerns of micro-mobility users. The effectiveness of frequently used data augmentation techniques was also examined to detect the presence of micro-mobility users and equipment usage with higher accuracy. In this direction, two different datasets (D1_Micro-mobility and D2_Helmet detection) and a total of 46 models were established and the effects of data augmentation techniques on YOLOv12 model performance outputs were evaluated with Preference Ranking Organization Method for Enrichment Evaluations (PROMETHEE), one of the Multi-Criteria Decision-Making (MCDM) methods. In addition, the determination of Multiple Model Ensemble (MME), consisting of multiple data augmentation techniques, was also carried out through the K-means clustering–Elbow method. For D1_Micro-mobility datasets, it is observed that MME improves the model performance by 19.7% in F1-Score and 18.54% in mAP performance metric. For D2_Helmet detection datasets, it is observed that MME improves the model performance by 2.36% only in the Precision metric. The results show that, in general, data augmentation techniques increase model performance in a multidimensional manner.

Heavy-duty diesel vehicle NOX emissions and fuel consumption: Remote on-board monitoring analysis

2025-06-19

Suyan Li , Gang Li , Liqiang He +6 more | Transportation Research Part D Transport and Environment

Emission Rates for Light-Duty Truck Towing Operations in Real-World Conditions

2025-06-19

Bumsik Kim , Rohit Jaikumar , Rodolfo Souza +7 more | Atmosphere

Light-duty trucks (LDTs) are often used to tow trailers. Towing increases the load on the engine, and this additional load can affect exhaust emissions. Although heavy-duty towing impacts are widely … Light-duty trucks (LDTs) are often used to tow trailers. Towing increases the load on the engine, and this additional load can affect exhaust emissions. Although heavy-duty towing impacts are widely studied, data on LDT towing impacts is sparse. In this study, portable emissions measurement systems (PEMSs) were used to measure in-use emissions from three common LDTs during towing and non-towing operations. Emission rates were characterized by operating modes defined in the Environmental Protection Agency’s (EPA’s) MOVES (MOtor Vehicle Emissions Simulator) model. The measured emission rates were compared to the default rates used by MOVES, revealing similar overall trends. However, discrepancies between measured rates and MOVES predictions, especially at high speed and high operating modes, indicate a need for refinement in emissions modeling for LDTs under towing operations. Results highlight a general trend of increased CO2, CO, HC, and NOx when towing a trailer compared to non-towing operations across nearly all operating modes, with distinct CO and HC increases in the higher operating modes. Although emissions were observed to be notably higher in a handful of scenarios, results also indicate that three similar LDTs can have distinctly different emission profiles.

Modeling Influence Area for Urban Signalized Intersections Using Crowdsourced Trajectory Data

2025-06-18

Pramesh Pudasaini , Bharat Kumar Pathivada , Yao‐Jan Wu | Transportation Research Record Journal of the Transportation Research Board

The operational influence of signalized intersections extends beyond the physical intersection area to the upstream and downstream segments, where vehicles decelerate, stop, and accelerate in response to traffic signals. Determining … The operational influence of signalized intersections extends beyond the physical intersection area to the upstream and downstream segments, where vehicles decelerate, stop, and accelerate in response to traffic signals. Determining this influence area is important for accurately evaluating the operational performance of intersections at the arterial or corridor level. However, the spatial extent of the operational influence of signalized intersections is not well-addressed in existing literature or practice. Therefore, this study aims to determine and model the influence area of urban signalized intersections using a large sample of crowdsourced trajectory data collected across 20 approaches in Tucson, Arizona, U.S. We developed analytical models for the upstream and downstream influence areas by examining the speed profiles of vehicles approaching an intersection. Results showed a high variation in drivers’ decelerating and accelerating behaviors while approaching signalized intersections. The acceleration rates for departing downstream were lower than the deceleration rates for stopping upstream. The downstream influence area was 20% to 90% longer than upstream. The impacts of operating speed and temporal factors on both influence areas are further analyzed and modeled using quantile regression. Additionally, we discuss the practical implications of the influence area in traffic operations, safety, intersection design, and emissions estimation.

Measurement and spatial-temporal distribution of carbon emission from urban sewage in the mountain city

2025-06-18

Zhoufeng Wang , Shaozhi Deng , Yanjing Zhang +2 more | Environment Development and Sustainability

Eco-driving strategy of fuel cell hybrid electric vehicle based on improved soft actor-critic algorithm in car-following scenario

2025-06-17

Zhumu Fu , Zhaohui Jiang , Song Gao +3 more | Journal of Power Sources

Retrofitting green spaces based on dispersion and absorption of mobile-source carbon emissions

2025-06-17

Xinlu Bai , Xin Fu , Zeqi Ren +2 more | Transportation Research Part D Transport and Environment

Real-traffic emissions of CO, NOx, CO2, and PM2.5 from vehicles using a portable emission measurement system

2025-06-17

Chunying Lu , Shuwei Dong , Siyuan Huang +7 more | Air Quality Atmosphere & Health

Optimización aerodinámica de autobuses en Ecuador: eficiencia energética y sostenibilidad

2025-06-16

Antonio Gabriel Castillo Medina , Giovanny Vinicio Pineda-Silva , Vinicio Sebastián Ribadeneira-Ramírez | Deleted Journal

The aerodynamic optimization of buses is fundamental to improving fuel efficiency and reducing pollutant emissions, especially in countries like Ecuador, where geographic and climatic conditions present additional challenges. This study … The aerodynamic optimization of buses is fundamental to improving fuel efficiency and reducing pollutant emissions, especially in countries like Ecuador, where geographic and climatic conditions present additional challenges. This study aimed to evaluate aerodynamic strategies applied to bus design through a systematic literature review, identifying the most effective technologies to minimize aerodynamic drag and improve energy performance. An exhaustive search was conducted in scientific databases such as ScienceDirect and Scopus, selecting studies published between 2019 and 2023 that addressed the use of aerodynamic devices, body modifications, and CFD simulations. The results indicated that spoilers and diffusers can reduce the drag coefficient by 9.23% and 3.68%, respectively, while the use of dimpled surfaces achieves savings of up to 6.4 liters per 1,000 km traveled. Additionally, body modifications, such as deflectors and optimized geometries, significantly reduce aerodynamic drag and improve vehicle stability. The research highlights the importance of CFD simulations and the integration of artificial intelligence in future studies to accelerate the development of more efficient designs. It is concluded that the implementation of these technologies, along with public policies that encourage their adoption, is essential for advancing towards more sustainable and efficient public transportation in Ecuador, reducing operational costs and the environmental impact of the automotive sector.

Longitudinal assessment of transportation-carbon emissions in European tourism

2025-06-16

Shan Zhang | Current Issues in Tourism

Method Design and Field Experiment Validation of Predictive Fuel-saving Cruise Control Based on Cloud Control Platform

2025-06-16

Keke Wan , Shuyan Li , Bolin Gao +2 more | Chinese Journal of Mechanical Engineering

Abstract Predictive cruise control (PCC) is an intelligence-assisted control technology that can significantly improve the overall performance of a vehicle by using road and traffic information in advance. With the … Abstract Predictive cruise control (PCC) is an intelligence-assisted control technology that can significantly improve the overall performance of a vehicle by using road and traffic information in advance. With the continuous development of cloud control platforms (CCPs) and telematics boxes (T-boxes), cloud-based predictive cruise control (CPCC) systems are considered an effective solution to the problems of map update difficulties and insufficient computing power on the vehicle side. In this study, a vehicle-cloud hierarchical control architecture for PCC is designed based on a CCP and T-box. This architecture utilizes waypoint structures for hierarchical and dynamic cooperative inter-triggering, enabling rolling optimization of the system and commending parsing at the vehicle end. This approach significantly improves the anti-interference capability and resolution efficiency of the system. On the CCP side, a predictive fuel-saving speed-planning (PFSP) algorithm that considers the throttle input, speed variations, and time efficiency based on the waypoint structure is proposed. It features a forward optimization search without requiring weight adjustments, demonstrating robust applicability to various road conditions and vehicles equiped with constant cruise (CC) system. On the vehicle-side T-box, based on the reference control sequence with the global navigation satellite system position, the recommended speed is analyzed and controlled using the acute angle principle. Through analyzing the differences of the PFSP algorithm compared to dynamic programming (DP) and Model predictive control (MPC) algorithms under uphill and downhill conditions, the results show that the PFSP achieves good energy-saving performance compared to CC without exhibiting significant speed fluctuations, demonstrating strong adaptability to the CC system. Finally, by building an experimental platform and running field tests over a total of 2000 km, we verified the effectiveness and stability of the CPCC system and proved the fuel-saving performance of the proposed PFSP algorithm. The results showed that the CPCC system equipped with the PFSP algorithm achieved an average fuel-saving rate of 2.05%–4.39% compared to CC.

Effect of heavy-duty engines aftertreatment system on particle emission properties above 10 nm

2025-06-14

Zuwei Zheng , Sheng Su , Tao Zhou +3 more | Fuel

Carbon emissions from public transportation in major Chinese cities: spatiotemporal analysis, decoupling trends, and key drivers

2025-06-13

Cai Jia , Xudong Wang , Chenglong Yang +4 more | Frontiers in Environmental Science

This study utilized public transport data from 28 major Chinese cities from 2018 to 2022 and employed methods such as carbon emission measurement, standard deviation ellipse analysis, the Tapio decoupling … This study utilized public transport data from 28 major Chinese cities from 2018 to 2022 and employed methods such as carbon emission measurement, standard deviation ellipse analysis, the Tapio decoupling model, and the LMDI decomposition method to ana-lyse the temporal and spatial evolution, decoupling states, and driving factors of public transport carbon emissions comprehensively. The results show that (1) total carbon emissions fluctuated markedly, and emissions dropped sharply in 2020 due to the COVID-19 pandemic, rebounded in 2021, and declined again in 2022 due to technological upgrades and policies. (2) The spatial distribution of carbon emissions follows a northeastern–southwestern pattern. The center of gravity shifted slowly southwards and slightly west-wards and was influenced by economic development and transportation policies. (3) The 28 cities were classified into four groups: Type I had high emissions but low intensity; Type II exhibited a positive decoupling trend; and Types III and IV showed weak decoupling. (4) Economic activities and line density were the main drivers of emission growth, whereas carbon emission intensity and transportation intensity increasingly inhibited emissions in recent years. On the basis of these findings, we propose differentiated low-carbon transportation policies, regional collaborative governance, and technology optimization to support urban transportation low-carbon transformation under the “dual-carbon” goal.

Clean and Zero-Emission Urban Buses: Compliance with EU Regulations and Fleet Transition in Seville

2025-06-13

Mauricio Navarrete , J. Serrano , José Antonio Vélez Godiño +1 more | Energy

Analysis of influencing factors and scales of agglomerate fog on expressways

2025-06-12

Hongna Dai , Jingwen Wang , Haixia Feng +3 more | PLoS ONE

To enhance the monitoring accuracy of agglomerate fog on expressways, this paper takes the frequently occurring agglomerate fog data on Shandong’s expressways as an example. Based on the analysis of … To enhance the monitoring accuracy of agglomerate fog on expressways, this paper takes the frequently occurring agglomerate fog data on Shandong’s expressways as an example. Based on the analysis of the spatiotemporal distribution characteristics of agglomerate fog, from the spatial perspective, it employs Geographic Weighted Regression (GWR) and Multi-scale Geographic Weighted Regression (MGWR) models to analyze the influence and scale of factors including Digital Elevation Model (DEM), DEM difference, water system density, Normalized Difference Vegetation Index (NDVI), Land Surface Temperature (LST) difference, and precipitation on agglomerate fog. The main research conclusions are as follows: agglomerate fog frequently occurred in the early morning during autumn and winter when the temperature difference is large. Three concentration centers of agglomerate fog-prone road segments were identified along Shandong’s expressways, located near Jiaozhou Bay, within intermountain basins of the central region, and across the northern plain of Mount Tai (where the Yellow River traverses the concentration center). The impacts of various influencing factors on agglomerate fog are ranked as follows: DEM > DEM difference > LST difference > water system density > NDVI > precipitation, among which DEM difference and LST difference mainly promote fog formation, whereas other factors generally exhibit inhibitory effect. The influence range (adaptive scale) of precipitation is the largest, at 673 meters, followed by the water system with an influence range of 599 meters, and NDVI shows the smallest influence range at only 44 meters. It holds significant importance for reducing the accident rate on expressways.

Impact of structural and CFD analysis on the cost of biogas-fueled gas engine exhaust pipes

2025-06-12

Rabia Kaymaz , M.T. Ir. Rusdhianto Effendi Ak. , Kürşat Tanrıver | European Mechanical Science

In this study, the effects of exhaust pipe design used in biogas-fueled cogeneration systems on engineering performance and cost were investigated. First, the existing system was analyzed by field work, … In this study, the effects of exhaust pipe design used in biogas-fueled cogeneration systems on engineering performance and cost were investigated. First, the existing system was analyzed by field work, and then structural analysis was applied with CFD (Computational Fluid Dynamics). The exhaust pipe route, pipe diameter, and material thickness of the existing system were evaluated, and design improvements were suggested. It was determined that the shorter pipeline application with the changes made in the pipe route and layout reduced pressure losses. Despite the use of an exhaust pipe with a smaller diameter and made of thinner material in the proposed new design, compliance with the standards was ensured, and it was shown to be safe against wind loads with finite element analysis. Considering the calculated maximum wind load of 5.52 kN and the weight of the system, the maximum stress value was calculated as 108.691 MPa as a result of the Von Mises stress analysis applied to the exhaust pipe system in the finite element analysis. This value showed that the system was 1.56 times safer. In the deformation analysis, the maximum displacement value was measured as 0.13 mm, and this value is ideal. In the cost analysis, it was determined that the proposed new system provides a cost reduction of approximately 53% compared to the existing system. The results obtained emphasize the importance of engineering analysis in exhaust pipe design, and show the applicability of the approach to increase economic and environmental sustainability in industrial facilities.

Regional disparities, dynamic evolution and influencing factors of transportation sector carbon emissions efficiency in China

2025-06-12

Zhimin Peng , Miao Li | Environment Development and Sustainability

Life-cycle carbon emissions of autonomous electric vehicles in varying traffic situations

2025-06-12

Kai Huang , Z. Y. Zhang , Xiang Wang +2 more | Transportation Research Part D Transport and Environment