one way vs two way tours

I would like to create a tour of a canyon. The challenge I have is that I want to create some general information about the canyon at the beginning of the tour. The tour can start from either direction though.

I was thinking about creating two different routes so that I can set the triggers differently for the same file. But, if tourguide uses proximity for the POIs then no matter how I set it up it will give the overview audio at both ends of the canyon. Anyone know how to get around this?

Good Question

This is one of the situations that is challenging for the way that TourGuides currently work. What I have considered for situations where you have say a 2 way road is you specify the activation distance to be tight (ie 10m) and basically have one tour go down one side of the road and another tour go down the other side. I think you could do the same thing even if you don't have lanes. Depends on how wide the canyon pass is. It's important that the lat and lon coordinates be accurate and that your GPS device be WAAS capable to get the 5m accuracy and use your device at the location to find those coordinates rather than use Google Earth or Yahoo Maps to get the coordinates.