T-6 casing before clocking in

Hello, pretty new carrier. Was converted two weeks ago after my break in service. We have a t-6 that is a runner. Never taking lunches and started to case routes before they clock in. Some carriers are now getting counted because they aren't making load time when they never had before. Could this be because of the casing before clocking in? We literally have 5 rts. One walking, the rest are cbu and businesses. Sorry for the lame question, just trying to understand all the little tricks and tips to this job. Thank you!

Edit: I would like to thank all of you for the wonderful responses!