Disclosed are systems and methods for reducing the amount of messaging between aerial vehicles and between controllers of aerial vehicles and simplifying aerial vehicle traffic management. In one implementation, a large service area, such as the United States, may be separated into a series of hierarchal regions. Rather than sending notifications to all agents (e.g., aerial vehicles, controllers) in the service area, each agent may subscribe to one or more regions of the hierarchal regions and only receive messages intended for the subscribed regions. In one example, as discussed below, messages for a particular region are only sent to agents subscribed to that region. Other agents within the larger service area do not receive the messages as they may not be relevant to those agents.