I saw this on the back of a delivery van two days ago.

Problem:
The sign writer converted a singular noun into a possessive instead of into a plural noun.

Explanation:
Book authors such as Lynne Truss are bang on when they say that sign writers have a propensity to put apostrophes where they do not belong.

The sign writer for the delivery van is guilty of this offense.

The sign writer either should have left the noun in singular form (“DRIVER”) or should have used the plural form (“DRIVERS”).

The writer probably wanted to be somewhat generic — and not pick on the driver of the van to which the sign is attached — and use the plural form of “DRIVER”.

One humorous aside: There was no telephone number to call for reporting a lack of courtesy!

Solution:
“REPORT DISCOURTEOUS DRIVERS TO”