If you want directions, just say “Ok Google, navigate to…” and see turn by turn navigation in your smartwatch in full screen. When you are not looking at screen, it will be on screen at power saving mode to save battery.
Google also confirmed that many travel apps will also be there integrated with Maps app to offer you lot more information. For example, you can use HotelTonight to track hotel rates and get notifications on your smartwatch. Glympse, Trulia, Zillow, Foursquare, Tripadvisor are few other apps available for Android wear to offer information on your wrist.