Timeline used like mecanim OR blend two timelines together?

I am trying to get my humanoid character animated using timeline like mecanim, (as in have different timelines that have similar or same tracks blend together) is this possible?

Using just mecanim I can easily create an animator state machine, but what I would like to be able to do is have say a timeline for walk forward animation and a timeline for strafe sideways and have the animations from the tracks blend when switching timelines?

So essentially I need to blend two timelines together, what is the best way to do this?