I don't know if this is a possibility or not, but for the drive time rings on Business Analyst Online it would be nice to take out certain areas. For example if I have a small town 15 miles east of a city, and I would like to do a 20 minute drive time to the small town. I assume that people in the city will not drive 20 minutes to the small town for a restaurant, however the rural area population east of the small town is likely to drive to the small town for a restaurant. I want to more or less cut in half the drive time ring to only include the area north/south/east of the small town, not the area west between the small town and city. I do not want to include a population in drive time rings that I do not think will drive 20 minutes to the small town for food. Does that make sense?
Maybe an algorithm that estimates where the “population watershed divide” would be for drive time?