IRouteEventSource and RouteEventSource

From this ArcObjects diagram at: http://help.arcgis.com/en/sdk/10.0/a...00000138000000, it can be seen that the RouteEventSource class has 2 interfaces, and one of the interfaces is the IRouteEventSource. However, in VS 2010 Object Browser, I can see that the IRouteEventSource contains dozens of methods and properties, but none of the methods and properties of the IRouteEventSource is displayed in the RouteEventSource class. Can someone explain this?
Besides, I want to create a RouteEventSource object, how can it implement the IRouteEventSource?
Thanks.