I've had some issues with UPS deliveries in the past and found that there really is no consistency. If the package requires a signature, I've been told that I either have to be there, pick it up at a distribution center, or have a neighbor sign for it.
Since they only deliver between 9 am and 6 pm and I'm not home those hours, this became an issue.
After repeat calls to let them know that this policy stinks and that I don't have time to drive the 45 minutes to the nearest distribution center, it now appears that they just leave most of my things for me without requiring a signature or they try to deliver as late in the day as possible since my husband is usually home by 5:00 pm.