Beyond the Townhall: Spatial Anchoring and LLM Agents for Scalable Participatory Urban Planning
This provides a practical tool for cities and policymakers to enhance inclusive participation in sustainability planning, though it is incremental as it builds on existing digital and LLM technologies.
The paper tackled the challenge of limited public involvement in participatory urban planning by developing a scalable digital platform with a navigable digital twin and LLM assistants, which in a randomized controlled experiment (N=195) significantly improved information recall and shifted participant feedback toward community-oriented sustainability benefits.
Participatory urban planning is central to sustainable city-making, yet the technically demanding nature of such interventions often limits meaningful involvement by diverse publics. We introduce a scalable digital participation platform that embeds sustainability projects within a navigable digital twin. Citizens experience a guided virtual walkthrough with audio narration employing the method of loci and spatial anchoring to support mnemonic encoding and recall. This immersive interface is augmented by two purpose-built LLM assistants: one delivers source-grounded factual clarifications, while the other facilitates reflective discussion. We evaluated this system in a randomized controlled online experiment (N = 195) against conventional industry practices (static visualizations and text-based consultations). Results show that spatially anchored immersive presentation significantly improved information recall, which substantially shifted participants' attention from individual inconveniences to collective, community-oriented sustainability benefits. Consequently, participants provided significantly more constructive, solution-focused feedback to the (simulated) municipality. These findings establish a practical tool for cities and policymakers to foster inclusive, democratic participation in sustainability transitions.