I wish someone would prove that it's wrong. In the 1975 study we looked back to the beginning of intercity bus service in Oregon, even a bit into the stagecoaches that preceded them. A lot of the bus routes were set up by the railways to replace money-losing branch and local main line trains.
We hypothesized as to what caused the one-generation phenomenon but never formalized it because of a change in administration. When I lived in Alberta I began to see the same thing. Then I moved to Colorado and it was like going to a movie that I had seen before. (The reason for the timing is that Oregon was ahead on its paved highway program and then its interstate highway construction, so it developed the consequent problems sooner.)
There is an urban transit parallel, although colored by more intense politics. It was rarer in Canada due to so many streetcar systems already being owned by governments or electric utilities. In the U.S., however, the interval between the end of streetcar service and the collapse of the replacement privately-owned bus company was about a generation.
There are long-term ironies in this story. Trudeau pere was in charge for the 1977-1981 rail cutback. Trudeau fils is in charge now. And I can't recall a train-off case where the availability of competing bus service wasn't cited as a justification.
Superliner trains' removal and restoration of cars 2024