Just read a thread on camping etiquette and dogs

Mine are better about going in unfamiliar places or in public than going where other dogs are present or have been. Those dog exercise areas have always been a problem. So is rest stops that have designated areas for pets. Although those areas are usually quite large and we can find a less "used" area for them to stop sniffing long enough to go.

It is true, however. Despite our best efforts you can't talk to a dog and reason with them. It takes training and sometimes that just takes time.