That's a good question. I would say you'd pass out after you land on the card, since that represents you actually making the trip there.
Detours cannot be accessed by cars in any of the 8 directions with the exception of the start and goal Jokers, so it acts more like a blockade. The exception is if you're walking, as it represents you walking through whatever that detour was. However, doing it this way costs an extra point of energy.