How do I choose means of travel when navigating to a POI in Epix?

Don't use the Navigate Activity. Including it was a poor decision from usability point of view because it seems to confuse everyone. I've seen questions like yours being asked many times.

Instead you can get to the Navigation menu from an activity of your choice. You can do that at the start of an activity when you press the menu button - look for 3 dots on the left at the start screen. You can also go to the navigation menu any time during an already ongoing activity by long pressing the same menu button.  

Thanks for the suggestion. This is an easier way to do it!! I can use motorcycle for car guidance as the Epix lacks any car activity.