Whenever possible, its better to get rid of dialogs and only bother the user when it is absolutely needed. Try using all information available and wonder if every dialog included is really useful. Of course, there will be moments when you will not be able to avoid dialogs so, make sure that you ask a clear question that avoids misunderstandings and tells the consecuenses of your actions. The dialog in this picture made us take a road 2 hours longer, just to avoid paying a 4 euro toll...
