  A new public conveyance model applicable to buses and trains is proposed in
this paper by using stochastic cellular automaton. We have found the optimal
density of vehicles, at which the average velocity becomes maximum,
significantly depends on the number of stops and passengers behavior of getting
on a vehicle at stops. The efficiency of the hail-and-ride system is also
discussed by comparing the different behavior of passengers. Moreover, we have
found that a big cluster of vehicles is divided into small clusters, by
incorporating information of the number of vehicles between successive stops.
