Well, first of all, optimization objective can be designed to include either worst travelling time or some kind of guaranteed time between each pair of points, so that the system would send a vehicle even if there is just one person waiting.
Secondly, why not make cars a part of the same system? Depending on the load the system could send a large bus, a small bus, a minibus/minivan or a small car.
Secondly, why not make cars a part of the same system? Depending on the load the system could send a large bus, a small bus, a minibus/minivan or a small car.