Fine-Grained Analysis of Bilingual Transportation Discourse on Reddit Using Large Language Models: A Quebec City Case Study
Open Access
- 29 September 2026
- journal article
- research article
- Published by MDPI AG in Smart Cities
- Vol. 9 (10) , 164
Abstract
Social media platforms generate large volumes of unsolicited textual content that reflect users’ perceptions of urban transportation. This study proposes a fine-grained annotation framework that classifies social media text into three constructs: attitude, intention, and reported behavior. Each statement is linked to a specific transportation mode and sentiment polarity. Two large language models (LLMs), GPT-5.5 and DeepSeek-Flash, were evaluated using few-shot in-context learning on 200 manually annotated English–French Reddit discussions from Quebec City, Canada. GPT-5.5 was selected based on its mean joint relaxed F1-score and applied to 2475 remaining discussions. The model extracted 23,634 transportation-mode mentions and 10,760 mode-specific construct statements after deduplication. Public transportation was the most frequently mentioned category and had the highest within-mode proportion of negative statements, although its positive statements outnumbered its negative statements. Attitude was the most frequently identified construct, while intention was the least frequent. The framework distinguishes evaluations, future plans, and self-reported actions or experiences, providing a more detailed description of transportation discourse. Given the Reddit sample and remaining extraction errors, these findings are exploratory and may complement other evidence used in sustainable urban mobility planning.Keywords
Funding Information
- Environment and Climate Change Canada (EDF-CA-2021i024)
This publication has 28 references indexed in Scilit:
- The behavioral dimension of transport decarbonizationnpj Sustainable Mobility and Transport, 2026
- Harnessing Social Media to measure Traffic Safety Culture: A Theory of Planned Behavior approachIEEE Access, 2025
- From social media to policy: Public insights on transport communication and services in QueenslandTransportation Research Interdisciplinary Perspectives, 2025
- Choices for climate action: A review of the multiple roles individuals playOne Earth, 2023
- Understanding Young Commuters’ Mode Choice Decision to Use Private Car or Public Transport from an Extended Theory of Planned BehaviorTransportation Research Record: Journal of the Transportation Research Board, 2020
- The effectiveness of an intervention to promote active travel modes in early adolescenceTransportation Research Part F: Traffic Psychology and Behaviour, 2018
- Greenhouse gas impacts of different modality style classes using latent class travel behavior modelJournal of Transport Geography, 2017
- Exploring the capacity of social media data for modelling travel behaviour: Opportunities and challengesTransportation Research Part C: Emerging Technologies, 2017
- Enhancing transport data collection through social media sources: methods, challenges and opportunities for textual dataIET Intelligent Transport Systems, 2015
- The theory of planned behaviorOrganizational Behavior and Human Decision Processes, 1991