We didn't use the internal buses, but what happens is, a bus comes in and rides around CBR twice, doing internal, then the third time, the driver turns his sign to say wherever he is going next (Magic Kingdon, AK, MGM etc....) I think all the buses do this, I don't think there is just one bus that rides around all day as internal, at least that is how the CM at CBR's bus stop explained it to me.