TAP&SE international conference is a forum to discuss a wide variety of questions related to the impacts of the transport sector on all parts of the environment, including atmosphere, climate, terrestrial ecosystems and the marine environment.
Road transport is currently one of the main sources of air pollution in urban areas. To accurately understand the high concentrations of pollutants that occur in certain urban areas and their influence on the actual exposure of the population, it is necessary to estimate the contribution of road traffic to atmospheric emissions in great detail. Models are often used for this. Want to know more about road traffic emissions in your city?
Pint Of Science Festival is an international event that invites the most advanced researchers to share their knowledge with you in a relaxed and friendly atmosphere: the bar.
This year, the festival takes place from Monday, May 22 to Wednesday, May 24, 2023 and is held simultaneously and in coordination in several countries around the world. In Spain, the initiative is articulated by the Association for Scientific Dissemination “Pint of Science Spain” created with the purpose of organizing this festival.
Researcher from the IRTEMS project was selected to present the latest research on road traffic emission in cities during the session about Impact on Cities for the general public. Join us to understand how models can help us to understand traffic emissions in our cities and improve air quality:
What: Conoce las emisiones del tráfico en tu ciudad (life presentation in Spanish) Where: Bar ‘La Manuela’, c/ San Vicente Ferrer, 29 (Madrid, Spain) When: Monday, May 22, 2023, 7pm
Christina Quaassdorff during her presentation in Pint of Science 2023.Presenters at Pint of Science 2023 – session Impact on Cities.
Summary of the context and overall objectives of the project:
According to the World Health Organization (WHO), outdoor air pollution causes 4.2 million premature deaths annually, most of them in urban areas where both, emission sources and population concentrate. Therefore, tackling urban air quality constitutes a pressing priority from the social and political point of view. Road transport is often the main source of air pollution in urban areas worldwide. There are several methods and approaches that are useful for different scales of analysis. Usually, regional traffic emission models based on average speed or on traffic situations are commonly used at the city scale for the compilation of urban inventories. Still, this level of detail is not enough to understand the high pollutant concentrations that occur in specific urban environments generally associated to high traffic intensity and usually referred to as hot-spots. An integrated approach that provides city-wide traffic emission estimations with high resolution in time and space for hot-spots poses a major scientific challenge.
In recent years, there has been rising concern for the environment, and along with it, a rush, in a multitude of sectors, to research and develop new ways to prevent ecological collapse and improve sustainability. One sector of high importance is that concerned with road traffic in cities, where emissions produce severe effects on citizens’ health and the environment. New emerging technologies in transport are arriving and a change in urban mobility paradigm has begun and over recent years, significant progress has been made in reducing emissions of key air pollutants from the transport sector. But, this sector is still one of the main contributors to air pollution in cities in Europe and some traffic-related air quality issues remain in urban areas worldwide. Non-compliance with European air quality standards is often linked to traffic-related highly polluted microenvironments (hot-spots) that require local intervention in addition to city-scale plans and measures. This poses a unique opportunity to develop innovative tools needed to tackle urban air pollution.
To accurately understand the high concentrations of pollutants that occur in certain urban areas and their influence on the actual exposure of the population, it is necessary to estimate the contribution of road traffic to atmospheric emissions in great detail. Models are often used for this purpose can help us to understand traffic emissions processes and how to improve air quality in our cities. With this in mind, the EU-funded project IRTEMS is developing a high-resolution road-traffic-emission-modelling system that can be applied at city scale.
IRTEMS (Instantaneous Road Traffic Emissions Modelling System for cities) is a scientific programme funded by the European Commission (H2020-MSCA-IF-2019 GA896417). The project is being coordinated by Universidad Politécnica de Madrid (UPM) located in Madrid (Spain) with North Carolina State University (NCSU) located in Raleigh (USA) as a partner organization. The project duration is of 3-years from Feb 15, 2021 to Feb 14, 2024.
This research project aims to contribute to drastically improve our knowledge to estimate the contribution of road traffic to atmospheric emissions at the city level and in great detail. The expected output from this research effort is a significant contribution to atmospheric science with a decided focus on providing useful information and tools to air quality managers and decision-makers, so that the project is also relevant policy-wise, providing knowledge-based answers for measures to be implemented for good air quality in cities.
Main goal is to develop an instantaneous road traffic emission modelling system for its application at city scale by coupling a hybrid traffic model with a microscale emission model to provide highly detailed data for air quality simulations. This is done by means of:
Quantify individual vehicle trip emissions at high resolution by means of a road traffic emission modelling system.
Validate modelled vs. measured individual trip emissions.
Quantify spatial and temporal variation of emissions at the city level.
Integrate city scale road traffic emissions into microscale air quality models.
IRTEMS project flowchart
The final result is a useful and thorough tool to provide accurate city-wide emission results considering European traffic conditions. This tool will help to give knowledge-based answers for measures to be implement for a good air quality in the European Union cities taking into account gender dimension and ethical aspects in all steps of the project. For the purpose of the project a 2-year stay in the USA with experts on measuring and modelling emissions has been successfully completed and now a 1-year returning phase to an emission and air quality modelling reference group in Europe, located in Madrid, has started. Collaborations with enterprises of the transport sector and other research organizations with expertise on instantaneous traffic emission models are contemplated through the research program. This aspect reinforces the strong inter/multidisciplinary of the project to develop a powerful tool and to provide solutions involving different aspects to generate an important impact on society. On the other hand, this project is a career opportunity that will help to generate new research lines. All the research results and knowledge generated during the project is being openly accessible through scientific publications and several dissemination activities for different target audiences. This is helping to involve different sectors on the research activities from the EU, increasing the interest of a wider part of the society. In this case, by contributing to a better air quality in accordance with the targets of the European climate action plan through the analysis of air traffic emissions.
Work performed and main results achieved so far:
The project is contributing to the knowledge on how to reduce road and air traffic emissions providing scientific outcomes to provide accurate answers on traffic emission generation and possible reduction mechanisms.
During the first two years of the project different model approaches were analysed and main outcomes of that were that models can produce similar high resolution emissions outcomes when the key parameters such as engine power and load for each vehicle class in addition to detailed driving patterns in the emission estimation are correctly considered. This analysis demonstrates the importance of an accurate definition of the model parameters for a specific vehicle fleet so that the modules selected during the project need to consider the specific vehicle fleet of the area where it is applied. These results were published on Quaassdorff, et al., 2022 (1) (https://doi.org/10.1088/1748-9326/ac8b21).
Related to how accurate model estimations can be, the precision of a microscale model was evaluated in comparison to measurements. The main outcomes were that for a selected set of 10 vehicles the model was highly accurate, at 86% to 97% across pollutants, in locating measured hotspots and non-hotspots (2). The precision of the model in identifying hotspots depends on the pollutant and lower precision estimation can be related to the sample size.
Those have been main steps to contribute to the development of a high resolution modelling system that can be applied at city scale and in next steps of the project those results will contribute to its materialisation.
Quaassdorff, C., Smit, R., Borge, R., Hausberger, S. (2022). Comparison of microscale traffic emission models for urban networks. Environmental Research Letters. Volume 17:094030.
Quaassdorff, C., Khan, T., Frey, H. C. Accuracy of the predictions of modeled emission hotspots based on real-world measured vehicle activity and emissions. CRC Real-World Emission Workshop. San Diego, California, USA. March 13-16, 2022.
Progress beyond the state of the art, expected results until the end of the project and potential impacts:
There are several methods and approaches that are useful for different scales of analysis. To understand the spatial and temporal distribution of the emissions, typically, regional traffic emission models are used for the compilation of urban inventories and usually those are the most detailed data available at city scale. This level of detail is not enough to understand the high pollutant concentrations that occur on specific urban highly polluted microenvironments (hotspots). To accurately understand the influence of these very local high concentrations on the real exposure of the population, there is a need to estimate the contribution of road traffic to atmospheric emissions at city level but in great detail. For that, an integrated multi-scale approach is needed which is a crucial step to analyse potential air pollution abatement measures in cities. This ongoing project plans to generate a useful modelling system to analyse road traffic emissions at city scale with great detail to help to provide knowledge-based answers for measures to be implemented for good air quality in cities.
The main goal of the project is to develop a useful and thorough modelling system to provide accurate city-wide emission results for European traffic conditions that will be developed by means of the implementation of an instantaneous traffic emission modelling system with high resolution at city scale. It is expected that the modelling system is materialised as an ad-one module of commercial software or integrated in them as parameterizations which intends to be exploited.
This will help to take knowledge based answers for measures to be implemented for good air quality.
The Real-World Emissions Workshop is annually organized by the Coordinating Research Council to present research and contributions that improve emissions and air quality, and evolves in response to research needs.
At this year’s 33rd CRC Real-World Emissions Workshop, part of the work done under the IRTEMS project was presented on a platform presentation under the Emissions Modeling section.
The Marie Curie Alumni Association (MCAA) is a international non-profit organization established and supported by the European Commission and run by members encouraging networking and cooperation.
During this 2023 MCAA Conference and General Assembly held in Córdoba, Spain on February 24-25, 2023, the IRTEMS project was presented in two different sessions during the lightning talks and the poster session.
The Transportation Research Board (TRB) annual meeting is one of the biggest transportation related meetings with thousands of experts from all the transportation related sectors joining every year. The annual meeting host more than 175 standing technical committees representing almost every transportation mode and topic. The standing technical committees within TRB are communities of individuals who share an interest and expertise in a specific transportation sector.
This year, the the 102nd TRB Annual Meeting, the IRTEMS project was presented in two different sessions during the Young Members Council 6-minute showcase and poster session.
Christina Quaassdorff presenting the IRTEMS project at the 102nd TRB meeting
The mid-project progress meeting from the IRTEMS project took place on October 20, 2022 at North Carolina State University – NCSU (third country host) facilities, at Fitts-Woolard Hall with the program supervisors Dr. Rafael Borge and Dr. Andrew Grieshop and the experienced researcher for the project Dr. Christina Quaassdorff. During the meeting the main achievements of the project were discussed along with the next coming steps for the successful completion of the project.
The beneficiary institution supervisor meet in person the facilities at NCSU and provided a seminar hosted by the NCSU Environmental, Water and Coastal group on October 21, 2022 for around 25 students, faculty and researcher on Environmental Engineering. The purpose of the seminar was to present “Ongoing research activities on urban air quality in the Madrid Region (Spain)” providing an insight on the current research done by the group and collaboration opportunities.
Project meeting. From left to right Christina Quaassdorff (IRTEMS experienced resercher) and Rafael Borge (IRTEMS beneficiary institution advisor) and Andrew Grieshop (not in the picture)EWC seminar hosted by NCSU. From left to right Ricardo Morales, Rafael Borge (IRTEMS supervisor), Fernando Garcia Menendez, Andrew Grieshop (IRTEMS supervisor) and Christina Quaassdorff (IRTEMS experienced researcher).
This study shows differences between emission models and identifies key variables for high resolution estimations.
Graphical abstract from Quaassdorff et al, 2022.
Traffic-related air quality issues remain in urban areas worldwide. For this reason, there is an increasing need to estimate the contribution of road traffic to atmospheric emissions at local level with high temporal and spatial resolution. Modal models compute emission rates as a function of specific engine or vehicle operating conditions at the highest resolution (seconds). They can be applied for microscale studies being a cost-effective tool to emulate differences in emissions levels in road networks. Two modal emission models, the Australian PΔP (Power-delta-Power) and the simplified version of the European PHEM (Passenger Car and Heavy-duty Emission Model), PHEM-light model, have been used. Also, a comparison to a cycle-variable emission model (VERSIT+micro) has been performed.
This work aims to (1) examine and clarify the practical implications associated with using different models, and (2) identify key variables for microscale emission calculation in urban areas for the development of local road traffic emission inventories.
For the comparison of both modal models, the main variables involved in traffic emission calculation were identified. Driving patterns (i.e. 1 Hz speed-time profiles) for individual vehicles were generated with the traffic microsimulation model VISSIM for different traffic conditions. To understand the response of modal models, detailed estimations of NOx emissions and fuel consumption were compared for different vehicle classes. Instantaneous emission profiles for individual driving patterns are highly sensitive to speed-acceleration profiles, vehicle mass, and road gradient, which are essential variables for the emission calculation. Although there are differences between European and Australian models, engine power and load were used to map vehicle classes for a more consistent comparison.
One of the outcomes of this research is that it is essential to accurately define engine power and load parameters for each vehicle class in addition to detailed driving patterns to obtain high-resolution emissions estimates. In this sense, a larger number of vehicle classes included in the model provides more flexibility to develop representative emissions estimates. Emission predictions between modal models were reasonably consistent presenting larger differences with the cycle-variable model, despite both modal models being based on different on-road fleet measurements.
In conclusion, analyzing emission estimations for different traffic conditions demonstrates the importance of an accurate definition of the model parameters for a specific vehicle fleet.
