If I search for a "Starbucks" then the results are ranked by how far they are from my route. However, once I go to Starbucks I am not going to retrace my steps to get back on my original route, I am going to re-plot the fastest way to my destination. Thus, the cost of this search result was not 2x Distance from route, but (Distance traveled without going to Starbucks) - (Distance Traveled To Starbucks + Distance from Starbucks to destination)