On-road Transportation Research Articles

Numerical simulation on the combustion and NOx emission characteristics of a turbocharged opposed rotary piston engine fuelled with hydrogen under wide open throttle conditions

Under the stress of environmental pollutions and fossil fuel consumption caused by on-road transport, hybrid vehicles are attracting much attention. Opposed rotary piston (ORP) engines are a promising power source for hybrid vehicles, due to their compact designs and high power density. In this paper, combustion and emission characteristics of a turbocharged ORP engine fuelled with hydrogen were investigated to evaluate the overall performance of this engine. The results indicated that volumetric efficiency of this ORP engine was higher than 89.0% for all the given cases. Peak in-cylinder pressure was in the range of 51.0 ~ 69.0 bar; and 4000 RPM scenario had the maximum value, being benefitted from high intake temperature and pressure, and high volumetric efficiency. Combustion duration of this engine ranged 27 ~ 43° crank angle (CA), and combustion phase happened at 7.5 ~ 13°CA after top dead centre (TDC). Peak nitrogen monoxide (NO) formation rates were corresponding to 5 ~ 13°CA after TDC; accumulated NO decreased slightly after reaching the peak value for low engine speed conditions. Discharge pressure at the start of the exhaust stroke was higher than 6.0 bar, especially for 5000 RPM case whose value was approximately 11.0 bar. This ORP engine presented excellent torque characteristics, and the maximum indicated power density was approximately 104.0 kW·L−1 which was much higher than turbocharged four-stroke reciprocating engines fuelled with gasoline.

Personal exposure to airborne particles in transport micro-environments and potential health impacts: A tale of two cities

The present study investigated the personal exposure (PE) of commuters to fine particles (PM2.5) and black carbon (BC) in two cities: Singapore and Danang (Vietnam) with different socio-economic conditions. The PE measurement was conducted during a multimodal round trip from Singapore to Danang and back with various on-road transport modes in urban micro-environments within each city by using portable devices. Real-time assessment of PE revealed that more than 60% of the integrated inhaled dose of PM2.5 by commuters to occurred at airport concourses and transit micro-environments to/from the aeroplane by apron bus. Whereas for BC, the transit by apron bus made a major contribution (> 50%) to the total integrated exposure. The PE to PM2.5 and BC in transport micro-environments was an order of magnitude higher in Danang compared to Singapore while using various on-road modes of transport in each city. Elevated concentrations of airborne particles in Singapore and Danang were significantly contributed by heavy-duty diesel vehicles and motorcycles, respectively. Moreover, a reduction in years of life expectancy is likely to occur among urban commuters while using motorized transport compared to active mobility (cycling).

Mining urban sustainable performance: GPS data-based spatio-temporal analysis on on-road braking emission

The on-road braking emission has been proved by former studies to account for a considerable part of on-road transportation. To improve cleaner air in urban area, the spatio-temporal analysis on emission performance of on-road braking is necessary as a guideline for decision-making. In this paper, we propose a framework for analysis on the particle matter emission of on-road vehicle braking events on an urban scale. We used massive vehicle trajectories in Tokyo area with short time interval as the database for analysis. From the result, we found that within the in the study area, the average driving distance during braking takes up about 20.60% of total driving distance. The average quantity of PM10 emission from braking for each driving trajectory is 14.09 mg and the one from exhaust emission is 35.36 mg. The emission from braking can averagely occupy 39.85% of exhaust emission. What’s more, in our finding, the braking emission from heavy duty vehicle is 2.33 times of light duty vehicle. From the spatial distribution of PM10 braking emission, we found that braking emission usually happened in the city center and popular crowded areas due to the large traffic volume, as well as the main trunk roads of capital expressway or highway. We also found a different spatial pattern between the light duty vehicle and heavy-duty vehicle. In temporal change, we found that rapid peaks during the rush hour on weekday and contrastive stabilization on weekend. We believe our finding can provide a clearer pattern and understanding on the emission behavior of on-road vehicle braking.

PRELIMINARY ESTIMATION ON AIR POLLUTION LOAD OVER BOGOR CITY TOWARDS DEVELOPMENT OF CLEAN AIR ACTION PLAN

Emission inventory (EI) data are crucial to provide source apportionment and relative strength of various air pollutant sources in a city. The process of EI compilation can be either bottom-up or top-down, which depends on data availability and other resources. For a city like Bogor, known as a buffer zone of the capital of the Republic of Indonesia, these EI data are now available only for greenhouse gases (GHGs) but not for the air pollutants. Therefore, a top-down EI was designed and implemented for the city in the base year of 2016. Note that the sources of activity data were compiled from the previously arranged GHGs EI database as well as some other data gathered from the local authority. We adopted the EI framework of the Atmospheric Brown Cloud Emission Inventory Manual spreadsheet for the compilation. We included SO2, CO, NO2, PM10, PM2.5, NMVOC, and PM components (black carbon and organic carbon). Point sources, area sources, as well as mobile sources, were considered in the emission estimation. The latter species were included as they are known as strong short-lived climate-forcing pollutants (SLCPs). On-road transport contributed significantly to SO2, NMVOC, and PM2.5, with a portion of 60-86% of the total emission. Industrial combustion sources dominated the shares to the total emissions of NOx (91%) and CO (92%). Based on this baseline information, we then proposed the source wise clean air action plan for the city in order to reduce the emission. A more accurate and up to date EI database should be done through a survey to get local representative activity data and to be compiled on a regular basis.

Air quality and fossil fuel driven transportation in the Metropolitan Area of São Paulo

In this paper, we use origin and destination mobility surveys and high-resolution assignment and emission models to study air quality and short-lived climate pollutant impacts related to on-road transportation in the Metropolitan Area of São Paulo (MASP). To begin with, we calculate transport carbon dioxide (CO2) emissions from fossil fuel-driven vehicles (light and heavy-duty) at spatial and temporal resolutions of 500 m and one hour, by means of traffic demand forecasting. These estimates, carry out for 2007 and 2012, are based on passenger and freight trips and the height of the atmospheric boundary layer, among other variables. These proxies depend also on ancillary parameters as particulate matter concentrations and dilution rates. In the second place, we evaluate the changes in CO2 emissions from the MASP (3%/year). Transport emission inventories combine mobility surveys and road network assignments with air quality data. In spite of using different methodologies, bottom-up road link assignments versus top-down vehicle activity-based and fuel consumption approaches, the estimated CO2 emissions are consistent with the Official São Paulo State's Inventory. This work found that the CO2 emissions in MASP were 10,044 and 11,503 t Ceq./day in 2007 and 2012 (73% light and 27% heavy vehicles), respectively. On-road emission patterns agree with the spatial-temporal variation of transportation journeys and corresponding passenger and freight network assignments. Temporal patterns, diurnal, weekly and monthly, were determined using traffic counts and congestion surrogates. The patterns were also crosschecked with average CO2 measurements, available for 2014 at the road (western area of MASP) and background sites (Jaraguá Peak). Kerbside road measurements showed two prominent peaks associated to the morning (437 ± 45 ppm) and night rush hours (435 ± 49 ppm), coupled to low values of boundary layer height (313 m) and dilution rate (329 m2/h). Background values (414 ± 2 ppm) were subtracted from on-road measurements to estimate excess CO2 (12 ± 8 ppm) directly attributed to vehicles. The inventory reflects the relationships between traffic patterns and emissions, and the developed methodology could be used to evaluate the impacts of forthcoming urban transport and emission control policies. In the future, our estimates will be verified with ground measurements of CO2 concentrations over a bigger monitoring network in the MASP.

Comprehensive study on boil-off gas generation from LNG road tankers under simultaneous impacts of heat leakage and transportation vibration

The minimization and utilization of boil-off gas (BOG) during the production, storage, and transportation of liquefied natural gas (LNG) have drawn wide interests. However, current studies on quantification of BOG generation still need to be improved because the mechanical vibration impact on BOG generation has seldom been considered in most of LNG studies. In this paper, the dynamic BOG generation under both heat leakage and vibration impact during the LNG on-road transportation have been quantitatively investigated via the integration of computational fluid dynamics (CFD) and process dynamic simulations. First, a multiphase LNG model is developed to characterize the thermal energy increment due to on-road vibration effect by CFD simulations, where a user-defined function (UDF) is employed with the dynamic mesh algorithm. Next, the vibration-induced thermal energy is introduced into a process dynamic model, where a heat-leakage considered LNG tanker is simulated to quantify the total BOG generation during the LNG on-road transportation. This work for the first time addresses two root causes of BOG generation with both CFD and process dynamic simulations, which lays a solid foundation for future BOG minimization and utilization during various LNG transportation, storage, and applications.

Interlinkage between water-energy-food for oil palm cultivation in Thailand

Biofuels for use in on-road transportation have been promoted in Thailand over the past decade to reduce dependence on imported fossil resources as well as possibly reducing greenhouse gas emissions. This has led to an increase in production of biodiesel which is produced from palm oil. However, as palm oil is also used for food, it is important to take this into consideration as well. Also, oil palm cultivation is rather water-intensive. Hence, it is necessary to analyze the interlinkage between water, food, and energy to have a holistic understanding and prevent trade-offs when addressing one issue in isolation. The water-energy-food nexus for oil palm cultivation in Thailand has been conducted following two widely used methods, the Water-Food-Energy Nexus (WFEN) and Water-Energy-Food (WEF) nexus assessment method. The results are demonstrated as a single score, which is easier for suggesting a suitable area for oil palm plantation. The assessment indicates the southern region of Thailand is the most suitable for oil palm plantation. The recommendation is consistent with the suggestion of the government, based on land and climate suitability. However, this study considers more comprehensive aspects including various other environmental aspects. Oil palm cultivation mainly relates to the amount of freshwater consumption, leading to the increment of fuel consumption for pumping water. On the other hand, the effectiveness of fresh fruit bunch yield (for food and energy production) should be developed in the future. Besides, the results recommend the central region for the expansion of oil palm cultivation in the future because of the availability of a good irrigation infrastructure.

Capturing uncertainty in emission estimates related to vehicle electrification and implications for metropolitan greenhouse gas emission inventories

Various sources of uncertainty exist in current on-road emission and energy consumption modelling approaches, which could affect the evaluation of energy and power distribution systems and related policies. These uncertainties are ever more pertinent today as urban transportation systems undergo drastic changes. This study presents a greenhouse gas emission and energy consumption accounting approach for on-road transportation, developed to estimate well-to-wheel emission distributions for household gasoline and electric vehicles, while capturing specific sources of uncertainty in the modelling process. Using data for Greater Toronto and Hamilton, the combined effects of vehicle electrification and well-to-wheel emission uncertainty were investigated. Under the base case, and for the study years 2011 and 2017, mean values for daily regional greenhouse gas emissions from household transportation, were estimated at 31,000 and 29,000 metric tons of CO2eq. The results of the policy scenarios present insight into the effectiveness of electric vehicles at reducing emissions and point out possible risks of using deterministic and single point estimates in policy appraisal. A sensitivity analysis demonstrates that well-to-tank emissions have the largest uncertainty, while tank-to-wheel emissions contribute the most to total uncertainty as they make up 75% of total emissions.

Identifying User Satisfaction Level of Road services: A Focus on Rajshahi City Bypass Road, Bangladesh.

The entire nation of Bangladesh depends highly on on-road transportation than other alternative routes, and this sector plays an essential role in the country’s overall communication. In the present competitive scenario of any country, every sustainable development of infrastructure, especially in road services depends on effective management of the road user’s needs and expectation. Every service provider or concerned organisation need to understand and meet the road user’s requirement. To perceive the road user’s demand, the present study initiates a survey to key out the drivers of user satisfaction, estimate current satisfaction levels and capture the various issues that determine the future road service requirement of a newly constructed road in Rajshahi. The study primarily focuses on quantitative methods to represent the database. Formulating a mathematical model like Factor analysis and linear regression, the evaluation criteria are employed to identify the road user satisfaction level. The criteria’s weights have obtained through the Analytical Hierarchy Process (AHP) method for understanding the future road service requirement. A structured questionnaire with a sample of 250 and expert opinions have included for the data collection procedure. The stratified random sampling method has used in this research. Five complex variables namely Comfort, Safety, Amenities, Roadside Signage and Emergency services are considered to discover the overall satisfaction level in Rajshahi City Bypass Road. The study concluded with an exciting finding that road user comfort has a high impact on the whole satisfaction level, among other factors considered in this study. To evaluate the future needs and expectations of better road infrastructure development, Expert gives priority to the safety of road user. This study will assist the policymaker for future priority basis sustainable decision making, and the methodology adopted herein can be replicated globally.

New Emission Inventory of Carbonaceous Aerosols from the On-road Transport Sector in India and its Implications for Direct Radiative Forcing over the Region

ABSTRACT In this study, we categorized detailed mass-based emission factors (EFs) by age, calculated new estimates of fuel use, and developed spatially resolved emission inventories of constituents (PM2.5, black carbon [BC], and organic carbon [OC]) in the fine aerosol generated by the on-road transport sector in India. On a national level, this sector released an estimated 355 (104–607) Gg y–1, 137 (47–227) Gg y–1, and 106 (34–178) Gg y–1 of PM2.5, BC, and OC, respectively, for the base year 2013, contributing nearly 7%, 17%, and 6% of the total emissions for each constituent. Although super-emitter vehicles comprised only 24% of the total traffic volume, they were responsible for 67% and 47% of the national PM2.5 and BC emissions, respectively, which indicates that eliminating these vehicles may rapidly reduce emissions from the on-road transport sector in India. To predict the direct radiative forcing (DRF) from BC emissions in this sector, we then input emission estimates for the carbonaceous aerosols into the Community Atmosphere Model (CAM5) global climate model and found a positive DRF of up to 6 W m–2 at the top of the atmosphere (TOA) and a negative DRF of up to 10 W m–2 at the surface, suggesting that as much as 16 W m–2 of energy remains trapped within the atmosphere. With the rapid economic growth and continued urbanization, the transport sector in India is likely to further expand in the future and hence requires immediate attention in order to reduce the BC burden and improve air quality in the nation.

Gasoline-ethanol blend formulation to mimic laminar flame speed and auto-ignition quality in automotive engines

Several environment agencies worldwide have identified biofuels as a viable solution to meet the stringent targets imposed by future regulations in terms of on-road transport emissions. In the last decades, petroleum-based gasoline has been increasingly blended with oxygenated fuels, mostly ethanol. Blending ethanol with gasoline has two major effects: an increase of the octane number, thus promoting new scenarios for engine efficiency optimization, and a potential reduction of soot emissions.3D-CFD simulations represent a powerful tool to optimize the use of ethanol-gasoline blends in internal combustion engines. Since most of the combustion models implemented in 3D-CFD codes are based on the “flamelet assumption”, they require laminar flame speed as an input. Therefore, a thorough understanding of the gasoline-ethanol blend chemical behavior at engine-relevant conditions is crucial. While several laminar flame speed correlations are available in literature for both gasoline and pure ethanol at ambient conditions, none is available, to the extent of authors’ knowledge, to describe laminar flame speed of gasoline-ethanol blends (for different ethanol volume contents) at engine relevant conditions. For this reason, in the present work, laminar flame speed correlations based on 1D detailed chemical kinetics calculations are derived targeting typical full-load engine-like conditions, for different ethanol-gasoline blends. A methodology providing a surrogate able to match crucial properties of a fuel is presented at first and validated against available experimental data. Then, laminar flame speed correlations obtained from 1D chemical kinetics simulations are proposed for each fuel blend surrogate.

Environmental impact of the on-road transportation distance and product volume from farm to a fresh food distribution center: a case study in Brazil.

The pollutants' emissions from on-road transport are critical pressure on the climate change scenario, and most developing countries rely on mostly diesel transportation. The current study aimed to estimate the environmental impact of the distance from the agricultural production area of fresh food (papaya, potato, and tomato) to a fresh food distribution center located in Campinas, Sao Paulo, Brazil. The way the products were carried was assessed for calculating the total transported volume. The total amount carried was measured, considering the number of trips multiplied by the total distance traveled within a year of supply. An online calculator was used to evaluate the amount of CO2 emission, and to allow the estimative of the amount of CO2-eq, that is the Global Warming Impact (GWP) in 100 years. The highest CO2 emission was identified in the potato transported from Paraná State to the distribution center, with a CO2-eq emission of 3237 t/year (64% of contribution), followed by the papaya from Bahia State (2723 t/year, 42% of contribution), and the tomato from Sao Paulo State (625 t/year, 71% of contribution). However, when computing the GWP, the highest value was found in the transport of potato from the Minas Gerais State (8 × 10-2 in 100 years) followed by the papaya from Rio Grande do Norte State (5 × 10-2 in 100 years) and the papaya from Bahia (3 × 10-2 in 100 years). The higher the amount of product transported by a trip, the smaller the environmental impact in the long run. A proper strategy to reduce the environmental impact would be to have large freight volume when transporting food from vast distances within continental countries.

Liquefied natural gas tanker truck-to-tank transfer for on-road transportation

Fugitive methane emissions from the liquefied natural gas (LNG) supply chain have revealed uncertainty in the overall greenhouse gas emissions reduction associated with the use of LNG in heavy-duty vehicles and marine shipping. Methane is the main constituent of natural gas and a potent greenhouse gas. Recent measurements have shown that the LNG offloading process had the largest contribution to methane emissions in the refueling portion of the supply chain. However, there are limited studies analyzing the LNG offloading process for small-scale applications. This study investigates six methods used to offload LNG from a tanker truck to an LNG refueling station and their contribution to methane emissions. A verified thermodynamic model is created by comparing numerical results with the experimental data collected from an LNG offloading process in a refueling station. The modeling results show that the LNG transfer by using a pressure buildup unit causes methane emissions as high as 104 g/kg LNG. In contrast, LNG transfer by using a pump and controlled pressure buildup unit provides the lowest risk of methane venting. Also, the results of parametric study indicate that rigid foam insulation can be considered as an economical alternative to vacuum jacketed pipes in LNG refueling stations.

Impact of Pavement Roughness and Deflection on Fuel Consumption Using Energy Dissipation

The transportation sector contributes up to 27% of the total greenhouse gas (GHG) emissions in the United States; on-road transportation is responsible for 84% of the entire sector, implying that vehicles are a major cause of global warming. To understand the fuel energy dissipated through a vehicle’s suspension and tires, researchers have recently examined stochastic pavement models combined with mechanics-based vehicle models. These approaches assume the pavement is nondeformable with a certain random roughness level. In this paper, a pavement–vehicle interaction model is developed that can accommodate both road roughness and the deflection of rigid pavement. A quarter-car model is considered to represent the vehicle, a filtered white noise model is used to characterize the road roughness, and a two-elastic layered foundation (Euler–Bernoulli beam for the top pavement and Winkler foundation for the subgrade) is employed to simulate the rigid pavement. Subsequently, an augmented state-space representation is formulated for the entire pavement–vehicle system. The Lyapunov equation governing the covariance of the response is solved to obtain the energy dissipation of the vehicle’s suspension and tires. Finally, examples are presented and compared with the nondeformable pavement model to understand the impact of rigid pavement deformation on vehicle fuel energy dissipation.

Life cycle greenhouse gas emissions of multi-pathways natural gas vehicles in china considering methane leakage

Natural gas has been promoted rapidly recent years to substitute traditional vehicle fuels. However, methane leakages in the natural gas supply chains make it difficult to ascertain whether it can reduce greenhouse gas emissions when used as a transport fuel. This paper characterizes the natural gas supply chains and their segments involved, estimates the venting and fugitive leakages from natural gas supply chains, decides the distribution among segments and further integrates it with life cycle analysis on natural gas fueled vehicles. Domestic natural gas supply chain turns out to be the dominant methane emitter, accounting for 67% of total methane leakages from natural gas supply chains. Transportation segments contribute 42–86% of the total methane leakages in each supply chain, which is the greatest contribution among all the segments. Life cycle analysis on private passenger vehicles, transit buses and heavy-duty trucks show that compressed natural gas and liquefied natural gas bring approximately 11–17% and 9–15% greenhouse gas emission reduction compared to traditional fossil fuels, even considering methane leaks in the natural gas supply chains. Methane leakages from natural gas supply chains account for approximately 2% of the total life cycle greenhouse gas emissions of natural gas vehicles. The results ascertain the low-carbon attribute of natural gas, and greater efforts should be exerted to promote natural gas vehicles to help reduce greenhouse gas emissions from on-road transportation.

Climate co-benefits of alternate strategies for tourist transportation: The case of Murree Hills in Pakistan.

This study explores the climate impacts of on-road tourist transportation with alternate mitigation strategies. To this end, greenhouse gas (GHG) emissions for 2016 and emissions under four "what-if" scenarios were estimated for a popular tourist site in Pakistan, i.e., Murree Hills, using the international vehicle emissions model. Alternate scenarios included occupancy optimization, bus transit system, and Euro II and Euro IV implementation. The emissions were further decomposed using the log mean Divisia index method to study the drivers of global warming potential (GWP) mitigation. As per the results, the total 20-year GWP for 2016 was equal to 51,262 tons CO2 equivalent, and maximum reduction was achieved under the bus transit system scenario having a 20-year GWP of 25,736 tons CO2 equivalent, i.e., 49.8% reduction. Relative to the base year, GWP reductions were also quite significant for Euro IV (46.8%), Euro II (45.8%), and occupancy optimization (32.3%) scenarios. For the base year, CO2 held a share of 87.3% in total emissions; however, its share in the 20-year GWP was 39.7% indicating its reduced impact on total GWP as compared to N2O, CO, NOx, VOC, and CH4. Based on the decomposition results for alternate scenarios, GWP mitigation was mainly driven by CO, CH4, NOx, VOCs, and partially by CO2, while N2O negatively affected GWP mitigation. These results provide several policy-level instruments for developing countries to design a transition to an eco-friendly tourist transport management system. The policy implications from this study can be used to promote an eco-tourism industry.

Do Urban Subway Openings Reduce PM2.5 Concentrations? Evidence from China

With the fast-growing consumption of automobiles in China, vehicle fumes appear to be one of the major contributors to PM2.5 (fine particles with a diameter of 2.5 μm or less) emissions. As a type of green transportation, Chinese urban subway transit has developed rapidly in recent years. This paper estimates the effect of urban subway openings on PM2.5 concentrations in Chinese cities. Using daily air quality data for 29 Chinese cities from 2013 to 2018, and using regression discontinuity design, we find that new subway openings reduce PM2.5 concentrations by an average of 18 μg/m3. The potential mechanism for this emission reduction is due to the offset in on-road transportation, and the use of cleaner energy. Also, central heating in winter, population scale, and city tier play crucial roles in the emission-reducing effect of subway openings. A series of robustness tests are conducted to support the fundamental empirical results. Targeted policy implications, such as optimizing the planning of urban subway construction and road network, fostering awareness of green travel, and promoting the innovation of emission-reducing technologies, are suggested for sustainable development in Chinese cities.

Trends in on-road transportation, energy, and emissions

ABSTRACTGlobally, 1.3 billion on-road vehicles consume 79 quadrillion BTU of energy, mostly gasoline and diesel fuels, emit 5.7 gigatonnes of CO2, and emit other pollutants to which approximately 2...

Water resource impacts of future electric vehicle development in China

In China, vehicle electrification is developed as a way to decouple people's increasing demand for on-road transport and concerns for adverse environmental impacts. Replacing conventional fuel with electricity not only yields impacts on air pollution and greenhouse gas emissions, but also on water resources. This study addresses such impacts for the first time. Based on China's existing plans, we expect China's future electric vehicles will grow from 5 million in 2020 to 80 million in 2030, requiring 47 to 335 TWh of electricity supplies respectively. In order to produce such amount of electricity, under a baseline scenario, 42.60 million m³ and 1.09 billion m³ of water is projected to be consumed and withdrawn in 2020, respectively, which are expected to grow to 324.45 million and 8.56 billion m³ in 2030. Deploying renewable energies offers considerable potentials cutting electric vehicles' indirect impacts on water resources by more than 20% as their productions require less water inputs than coal-fired power plants. Changing cooling technologies' impacts differ by regions, increasing water consumption in southern regions while reducing water consumption in the north. However, if water consumption avoided from avoiding conventional fuel productions is taken into account, compared to the counterfactual scenario where the same number of traditional vehicles will be deployed, future electric vehicles in China will lead to net decreases of 19.3, 64.3 and 89.7 million m³ of scarce water consumption nationally under baseline, high renewable and cooling technology change scenarios in the electric power sector respectively.

Impact of residential combustion and transport emissions on air pollution in Santiago during winter

Santiago (33.5°S, 70.5°W), the capital of Chile, is frequently affected by extreme air pollution events during wintertime deteriorating air quality (AQ) and thus affecting the health of its population. Intense residential heating and on-road transport emissions combined with poor circulation and vertical mixing are the main factors responsible for these events. A modelling system composed of a chemistry-transport model (CHIMERE) and a meteorological model (WRF) was implemented to assess the AQ impacts of residential and transportation sources in the Santiago basin. A two-week period of July 2015 with various days with poor AQ was simulated focusing on the impact on AQ with respect to fully inhalable particles (PM2.5) and nitrogen oxides (NOX). Three emission scenarios, within the range of targeted reductions of the decontamination plan of Santiago, were tested; namely 50% reduction of residential emission, 50% reduction of transport emissions and the combination of both. An additional scenario decreasing transport emissions in 10% was carried out to examine whether a linear dependence of surface concentrations on changes in emissions exists.The system was validated against surface and vertically resolved meteorological measurements. The model reproduces the daily surface concentration variability from the AQ monitoring network of Santiago. However, the model not fully captures the emissions variations inferred from the observations which may be due to missing sources such as resuspension of dust.Results show that, during the period studied, although both residential and transportation sources contribute to observed AQ levels in Santiago, reducing transport emissions is more effective in terms of reducing the number of days with pollution events than decreasing residential combustion. This difference in impact is largely due to the spatial distribution of the emission sources. While most of the residential combustion is emitted in the outskirts of the city, most of the transport emissions occur within the city, where most of the stations from AQ monitoring network of Santiago are located. As can be expected, the largest improvement of AQ in Santiago is achieved by the combined reduction of emissions in both sectors. Sensitivity analysis with 10% reduction in transport emissions reveals a linear behavior between emissions and concentrations for NOX and approximate linear behavior for PM2.5. The absence of secondary aerosols formation and dust resuspension in the current simulation could explain this deviation from linearity for fine particles. Nevertheless, it suggests that the results can be used for mitigation policies with emissions reductions below the 50% used in this study.