> "Yes, there's a round "Directions" icon. This time. Frequently, searches for a given address don't bring up that icon or any other UI affordance that indicates how I might get directions to the destination."

This is sadly a really common UX failure in a lot of different apps.

One thing that many people still don't seem to realize is that it's more important to be consistent than being smart. I like to call these "hide and seek" UI elements - they display conditionally in an effort to be smart (e.g., no directions are available to this place, so we hide the directions button). But in practice it just confuses users.

One thing I keep encouraging, to varying levels of success, is that UIs should always be consistent. If you are unable to provide a feature, disable that element with a helpful tip (e.g., graying out the Directions button and say "Directions not available from this address" or some such).

My favorite example of this is deleting a draft in gmail. Go make a draft and try to delete it. There's no button to delete it. Unless you click the checkmark! Then the button appears where previously there was whitespace. Ugh.

You have to find a real address before it can give you directions. Otherwise on the default maps page, you can switch directly to directions mode to input both start and end addresses.

http://i.imgur.com/jZyv7gZ.png

I can't say I've experienced the lack of a directions button, but I agree that's a major UI failure.