AI-generated knowledge in urban planning: chatbots and professional planners’ expertise in responding to public queries

Even as the public use of generative artificial intelligence (AI) has surged recently, its potential as an accessible source of general urban planning knowledge has remained understudied. This article collects urban planning questions on the Reddit social media platform and compares the quality of answers provided by verified professional planners with responses generated by ChatGPT. We find that our panel of expert evaluators preferred AI-generated responses over those provided by registered planners. This study is the first step in verifying the quality of knowledge on social media and comparing the knowledge base of generative AI to professional planners.