I'm pretty sure a drive-through isn't considered a public road in most jurisdictions, similar to how people usually don't worry about speed traps on Nürburgring.
Under australian motor law (on phone so I'm not going reference hunting but you can look it up) anywhere you can drive that isn't explicitly private (such as a driveway or a fenced off road on a farm) is a public road - this includes drivethroughs and car parks (even the mutistory carparks you have to pay to get in - if you can pay, as a member of the public, to get in then it's a public road).
