A driver that decides to retire and file for pension has thirty days to change his mind. Our most senior driver who is 69 years old did that, the only time I have seen it happen. That could hold up a bid going through. It may get posted, but held up.
Also, the second route I won in a bid was busted out after I trained on it two days with a supervisor on my car. This was about 28 years ago, I was forced to go back to my first route. We didn't have cover drivers back then, you were either a bid driver or a unassigned swing driver.