Is there an event for entering a NavArea?

I am looking for an event that fires when an agent starts using navigation nodes/links of a certain type of NavArea. This would allow me to define how an area should be moved through (for example: running, walking slowly, crouching…). If there is no such event, I guess any event would do that triggers when a navigation node is reached and the next one is picked by an agent. Then I could check what area the next node belongs to, which would be more or less the same, only less convenient.