Assumption 2 – Order: Taxis do not overtake each other
on the way to the terminal. This assumption implies that all
the taxis that are in transit and ahead of the querying taxi
eventually make it into the queue before the querying taxi.
Note that if these taxis do not enter the queue because the
queue is full, then this can only work in favor of the querying
taxi, never against, since as a result there can now only be
fewer taxis in the queue in front of it. For the purposes of
deriving strong results in our analysis, we assume that all
taxis in front of the querying taxi will actually join the queue