While there is not a way to access a full map using Google Maps on the Apple Watch, using Force Touch allows you to switch between walking, driving and transit directions to your home or work. You can also get directions to a location you recently navigated from your phone using Google Maps. And if you start a route on your handset, you can switch to your watch to navigate the rest of the journey.
There is also a new change for those using Google Maps on the iPhone. In the past, you used to have to open three separate pages to find out your estimated time of arrival at a location by walking, driving or taking mass transit. With today’s update, your ETA for all three methods of navigation are available on one page, all at the same time.
source: Engadget