Introduction
Hot spot analysis is a statistical tool to identify clusters in a dataset. In traffic management, identifying hot spots of $\text{CO}_2$ emissions might help to define measures for an overall reduction of emissions, e.g. by optimizing traffic light circuits in a hot spot. In the CITRAM project (Citizen Science for Traffic Management), citizens in three German cities (Chemnitz, Hamm and Krefeld) used the enviroCar App to collect extended floating car data (xFCD). The goal of the project was to understand how citizen science tools can contribute to improve traffic quality (e.g. efficient traffic flow, reduction of fuel consumption and emissions).