A network system coordinates users who provide geographical location-based services to users. Users can provide textual feedback regarding the services provided by other users. To create a safe user experience and encourage users to continue using the services, the network system determines safety risks of the users by analyzing the textual feedback from users along with metadata associated with the textual feedback. For example, the network system determines a safety score for a user based on classifying textual feedback according to different types of safety risk related to topics such as vehicle operation or interpersonal behavior. The network system can train classifiers using feature vectors derived from textual feedback previously received from users of the network system, which may be labeled in a supervised training process. The network system may provide interventions to high-risk users to help mitigate their safety risk and prevent safety incidents from occurring.