EGU21-5419, updated on 04 Mar 2021
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Error assessment of traffic emission estimates using novel mobility datasets.

Johannes Gensheimer1, Alexander J. Turner2,3, Ankit Shekhar4, Adrian Wenzel1, Frank N. Keutsch5, and Jia Chen1
Johannes Gensheimer et al.
  • 1Environmental Sensing and Modeling, Technical University of Munich (TUM), Munich, Germany
  • 2Department of Atmospheric Sciences, University of Washington, Seattle, WA, 98195, USA
  • 3Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
  • 4Department of Environmental Systems Science, ETH Zurich, 8092 Zurich, Switzerland
  • 5School of Engineering and Applied Sciences and Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, USA

The COVID-19 pandemic led to widespread reductions in mobility and induced observable changes in the atmosphere. Recent work has employed novel mobility datasets as a proxy for trace gas emissions from traffic, yet there has been little work evaluating these emission numbers.

We systematically compare mobility datasets from TomTom and Apple to traffic data from local governments in seven diverse urban and rural regions to characterize the magnitude of errors in emissions that result from using those mobility datasets as a proxy for traffic. We observe differences in excess of 60% between these mobility datasets and local traffic data, which result in large errors in emission estimates. These differences are in part driven by the usage of different baselines and the neglect of seasonality, but mainly they are caused by the individual representations of the datasets. The relationship varies strongly depending on time and region and therefore no general functional relationship between mobility data and traffic flow over all regions can be determined. Future work should be cautious when using these mobility metrics for emission estimates. Further, we use the local government data to identify actual emission reductions from traffic in the range of 7-22% in 2020 compared to 2019 for our study regions. Our full analysis is summarized in Gensheimer et al. (2020).

Gensheimer, J., Turner, A., Shekhar, A., Wenzel, A., & Chen, J. (2020). What are different measures of mobility changes telling us about emissions during the COVID-19 pandemic? Earth and Space Science Open Archive, 11. Retrieved from doi: 10.1002/essoar.10504783.1

How to cite: Gensheimer, J., Turner, A. J., Shekhar, A., Wenzel, A., Keutsch, F. N., and Chen, J.: Error assessment of traffic emission estimates using novel mobility datasets., EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-5419,, 2021.

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