Why does the dog bark?

As our Rocky Mountaineer passed a house along Lake Shuswap (a beautiful part of the British Columbia interior), a woman of late middle age could be seen waving enthusiastically at our train. Our car attendant Amanda explained that she greets every Rocky Mountaineer in this manner. This became so evident to the crew that eventually they learned her name, which is Doris. Ultimately Doris became a passenger of the train, deepening her attachment to the Rocky Mountaineer.

During her trip, Doris explained how she always makes to her front porch in time: Her dog announces the train’s approach by barking. End of story. But I kept chewing on this puzzle. There has to be an explanation for the dog’s unerring behavior. Have you figured it out?

I did. But before I explain, what’s your inspiration?—Fred W. Frailey