I have to respectfully disagree. I was a part-time sup and am now a full-time driver. In less than 2 years I was given the opportunity to drive. The avg. wait time in the center I was in for an hourly to have the same opportunity was between 5-7 years. Being a part-time sup greatly accelerated the time I had to wait.
But here is how I see the big picture of things, based on what route you choose. Of course, hourly has the option to go into management, and pt sups are given the chance to drive full-time hourly (albeit uncommon), but for this example, I have excluded those options, respectfully.
1: Hourly = PT hourly -> 22.3 -> FT PKG -> Feeder (based in order of top pay) ***
2:Mgmt = PT sup -> FT Specialist -> FT Sup -> Manager -> Division level -> District level -> Region level -> Special Corporate assignment -> Everything else above
Also keep in mind that there are several different supporting roles and specialty fields (departments) that management can go into, not just Package Operations. So based on this, it is my belief that the Management track has several more opportunities than the hourly track does.
Most part-time sups have no intention or desire to go full-time, whether it is driving or management. From my experience and conversations with numerous part-time sups, they do it for job experience (resume builder), the higher pay, and most importantly, tuition benefits. While hourly in earn and learn hubs/centers (usually large metropolitan areas) qualify for this benefit as well, almost all extended centers do not offer tuition reimbursement to hourly employees.
*I am not saying that management is better than hourly. I know first hand how hard drivers work. I also acknowledge that the over whelming majority of full-time hourly are happy where they are, enjoy their jobs, and receive a great wage and benefits. I am simply stating that overall, there are more opportunities for development, growth, and advancement starting out as a part-time sup than most people would like to acknowledge.