#TIL there's settings in #OpenTTD to make it so that passengers and mail actually have places to go to, rather than just seeking transport anywhere
by default it's manual, making passengers and mail behave like other types of cargo
if it's "symmetric", then the game will generate passengers who actually want to get to available destinations, with the same number wanting to go both ways
if it's "asymmetric", then the distribution will not be symmetric, more passengers may want to go one way than the other