That and a bathroom button. For a couple of reasons.Missed this response before. I had not relayed the suggestion, but I have now Thanks for the link.
1). It finds the nearest bathroom exit with possible ratings, so you know what you are getting into.
2). To keep Siri from continually saying 'please do a U-Turn' or some other directions while you are trying to quite her and navigate into a possible complex entry with Big Trucks and other 'lost' and tired bathroom break drivers.