How do you tell if a minor service road is access=private, destination, or permissive?

Let's assume you have a highway=service (alleyway/driveway) on private property in an urban area, with no signs restricting access. The local laws say that you can't cut through a corner parking lot to avoid an intersection, but nothing about using a longer such road as a mid-block connection. So how would the following examples be tagged?

1. Like a public alley, it connects two adjacent streets between buildings, and is commonly used by pedestrians and less often by motor vehicles. It is always de facto open to the public; there are no gates or fences.
2. A gate at one end is normally closed, making it a dead end most of the time for vehicles and pedestrians.
3. In a less urban setting, a big company headquarters has a major entrance from public roads. It is not clear from said roads where the entrance leads, since it looks like another public road, but once you get onto their property, you have to turn off before the gate and take a separate roadway out if you don't have business there. Obviously the road through and beyond the gate is access=private, but what about the public "oops" exit?