Warning that the trip crosses country boarder
I recently attended an ultra marathon in MI. Trying to leave the state to return to NY (I entered from the west side of the state) I found myself at the Canadian boarder. This would not normally be an issue, but not knowing I would be leaving the country, my passport was left home. I simply propose that if a route takes the driver through another country there should be a highly visible warning, much like when the route contains toll roads. Yes, I should have looked at the map, but I made an assumption that I feel is common, I would be warned if the route entered another country, and then returns to the initial country. This is different than a destination that is clearly intended to be in another nation.
Thank you!