How can I avoid a redelivery the next day when no one signs for Certified Mail on my USPS route?

When running a USPS route, Certified Mail is the easiest thing to disrupt your rhythm. Once, I went to an apartment building to deliver certified mail, the resident wasn't home, and I couldn't just leave a notice due to building access restrictions. New hires often just write 'notice left' and leave, but then customers complain about 'not seeing a notice,' and the station has to deal with the…