Conference Papers 2025

Seminar
Day 1 (17 Sep 2025), Session 3, Modelling sustainability, 16:00 - 18:00

Status
Accepted, documents submitted

Submitted by / Abstract owner
Nina Thomsen

Authors
Nina Thomsen, German Aerospace Center DLR (presenter)
Daniel Krajzewicz, German Aerospace Center DLR
Mariano Mertens, German Aerospace Center DLR
Michael Behrisch, German Aerospace Center DLR
Sabine Brinkop, German Aerospace Center DLR
Isheeka Dasgupta, German Aerospace Center DLR
Simone Ehrenberger, German Aerospace Center DLR
Christopher Kaiser, German Aerospace Center DLR
Jens Hellekes, German Aerospace Center DLR
Johannes Hendricks, German Aerospace Center DLR
John E. Anderson, German Aerospace Center DLR
Mattia Righi, German Aerospace Center DLR

Short abstract
This study presents ASE, a tool integrating models to assess land transport emissions and their climate impacts. It enables scenario-based analysis of transport emissions and mitigation measures at the urban, European, and global scales.

Abstract
The transport sector contributes significantly to climate change through its emissions of climate-active compounds (CO2 and non-CO2), underscoring the need for effective mitigation measures. To assess the impact of these measures, model-based projections are required to quantify both current and future emissions. The critical research questions remain on how these emissions translate into tangible climate effects, such as warming, and which mitigation strategies are most effective in reducing emissions to help meet climate protection targets.

This study introduces the Application Suite Emissions (ASE), a tool developed to address these critical questions. ASE integrates multiple models – including travel demand (activity), fleet, and climate models – into a cohesive service. This toolchain enables the assessment of transport emissions from various vehicle types, as well as their impacts on climate and the environment, across different future scenarios. Additionally, results can be provided at different scales and levels of granularity, based on the specific transport models applied: global, regional (Europe and Germany) and urban. The key advantage of incorporating these varying resolutions within a single service is that it allows for streamlined scenarios across all levels, providing consistent results tailored to the needs of different stakeholders.

The models used in ASE are well-established and provide reliable results across different scales. SUMO (Simulation of Urban Mobility) simulates urban and interurban vehicle and person movements with high temporal and spatial resolution, enabling analysis of traffic management, autonomous driving, emissions, and more (Alvarez Lopez et al., 2018). ULTImodel (Universal Transport Distribution Model) distributes road traffic across Europe based on socio-economic trends, using a gravity model and open data (Thomsen, 2023). Emissions are calculated by applying road-type-specific factors to the traffic load. TRAEM (Global Land Transport Emission Model) models CO2 and non-CO2 emissions from road and rail transport, integrating data on vehicle technologies, fleet regulations, and emission standards to generate scenario-based projections and provide emission factors (Dasgupta et al., 2024). Finally, emissions from these models are fed into TransClim (Modeling the Effect of Surface Transportation on Climate), which uses a 3D chemistry-climate model to calculate the climate impacts of transport emissions (Rieger and Grewe, 2022).

With this tool, mitigation measures that tackle both the technological development and regulation of transport can be simulated and their impacts quantified. For example, urban case studies can focus on the impacts of new vehicle types in urban fleets or changes in traffic regulations, including the calculation of wear emissions (tire and brake wear) through individual vehicle movement simulations. Additionally, the models allow for the analysis of medium-term traffic disruptions (e.g., construction projects or large events), highlighting the advantage of simulations over purely data-driven approaches for non-average traffic scenarios. On a larger scale, ASE enables the exploration of emission reduction measures, including the effects of low-emission vehicle market share regulations, new fleet CO2 limits, large-scale speed restrictions, and shifts to active transport modes (walking and cycling) in cities, with projections extending to 2050.

Literature:
Alvarez Lopez, P., Behrisch, M., Bieker-Walz, L., Erdmann, J., Flötteröd, Y., Hilbrich, R., Lücken, L., Rummel, J., Wagner, P., and Wießner, E.: Microscopic Traffic Simulation using SUMO. The 21st IEEE International Conference on Intelligent Transportation Systems, 2018-11-04 - 2018-11-07, Maui, USA. doi: 10.1109/ITSC.2018.8569938, 2018.
Dasgupta, I., Feinauer, M., Thomsen, N., Hellekes, J., and Ehrenberger, S.: A new approach for the bottom-up calculation of global road transport emissions. EGU24 General Assembly, 2024-04-14 - 2024-04-19, Vienna. doi: 10.5194/egusphereegu24-19573, https://elib.dlr.de/204117/, 2024.
Rieger, V. S. and Grewe, V.: TransClim (v1.0): a chemistry–climate response model for assessing the effect of mitigation strategies for road traffic on ozone, Geosci. Model Dev., 15, 5883-5903, https://doi.org/10.5194/gmd-15-5883-2022, 2022.
Thomsen, N.: ULTImodel [Computer software], Zenodo, https://doi.org/10.5281/zenodo.7817424, 2023.

Programme committee
Transport Models

Topic
Moving towards sustainable transport in a polarised world