Wes Stewart wrote:


28-628. Rights of real property owners

This chapter does not prevent the owner of real property that is used
by the public for purposes of vehicular travel by permission of the
owner and not as a matter of right from:

1. Prohibiting that use.

2. Requiring other, different or additional conditions than those
specified in this chapter.

3. Otherwise regulating the use as deemed best by the owner.

In other words, I get to regulate the speed (I've posted it as 10
MPH). I have no power to fine UPS, but I can still cost them money.

You are not reading the wording carefully; it is the "not as a matter of
right from" that you are missing. It very well may be a matter of right
if the private road is co-owned by the other property holders and this
ownership allows them the right to transact business in the way of
receiving deliveries as they choose.