How do I animate movement in different orientations?

I would like to animate an object in varying, smooth orientations to give the illusion of going forward along a path, reversing along a path without turning around, and going forward once again.

Here is an image to better illustrate things.

I know how to do step 1. Simply animate along a path with orientation along the path. The tricky part for me is step 2. I would like the object to go in reverse without turning around for a while, then going forward again at some point (step 3) just like before.

Any suggestions?