update
@allcoinminer, yes the idea is not bad, I will think about it.
But that would cost even more time, because even more runs.
I tends more to prepaid, someone buys 20 runs in advance and only 20 runs buyer gets on the reservation list
You are always open to ideas and that sounds great.
As a short fix, you may give a few hours for each previous ride participants to join the next ride and on the expiry of the reserved hours, those slots may be opened to everyone.