alt Hacker NewsNYC used to (or still?) enforced strictly parking violations by delivery companies. But they did it so evenly the companies just considered it a cost of doing business, and raised their rates accordingly. Not violating the law and still being in the business wasn’t an option, so no competitor could undercut the other by following the rules and not paying the fine.
Sounds like a scenario where something other than fines should be applied. Revoke plates fleetwide, tow any delivery trucks caught on the street with a mandatory 72 hour minimum impound time, with no access to the contents of the vehicle. And so on.