Is this one of those purely theoretical economics thing or Does this assume there is a different queuing stage from a moving stage? Otherwise it seems like the

Is this one of those purely theoretical economics thing or Does this assume there is a different queuing stage from a moving stage? Otherwise it seems like there are too many physical mechanics at play, like should I be able to join the line as soon as I see the line for the roller coaster start moving. How are ties broken if everyone tried to join the line at the same time.