According to Front5151 on the boards, the unusual swap of buses between Southern and Callowhill is because the 2008 New Flyer buses have passenger counters installed on them. Most of the hybrids on loan has been reported to operate on the Route 17. This is not the first time when buses were purposely assigned to a route due to passenger counters. Back in 2004, 5591 and 5592 were assigned on a daily basis onto 124 and 125 these routes because they counters installed.