Local management does not interpret USPS policy, procedure, or the contracts. That’s not their job. Interpreting this stuff is not a matter of opinion, with everyone’s opinion being equally valid. Each district has an entire department (Labor Relations) full of people who local management should contact to provide interpretation and understanding. And we, of course, have our union representatives.
Your office is not the first office that did not understand what 1/2 mile means. It is understood—by the people whose opinions count!—that it means one way.
I’m assuming you are a USPS employee who is having a problem getting packages delivered to your home? I originally thought you were a carrier who wanted to deliver beyond the 1/2 mile, which had me scratching my head why a carrier would want to do this.
I think your only recourse here is to contact your Congressman, since local management isn’t helping (and also stupid). Get them involved, share the info from the PS 603 that has been provided and see if that makes a difference.