Really? I've found the opposite and it seems to make far more sense.
With passengers in they can take their time and earn more money but without passengers they're not earning so in a hurry to find some.
With passenger they try to get from a to b quickly in order to get the next fare.
Without passenger, they take it easy trying not to burn fuel and keeping an eyes out for fare.
With passenger they try to get from a to b quickly in order to get the next fare.
Without passenger, they take it easy trying not to burn fuel and keeping an eyes out for fare.