[@BurningDaisies]

The corporate zones in the City are primarily the heavily-redeveloped urban core, several "warehouse districts" where space is at less of a premium, the railway, and the railway's immediate environs. :3

As I mentioned in the OP (I know there's a lot in there), law and order under local, State, and Federal government nominally still exist, and no area in the City is [i]technically[/i] under the entire administration of a Corporation. In other words, crimes are still brought before judges, police still patrol the area, and taxes are still paid. That said, depending on the area, and the Corporation involved, and the activity in question, some Corps have [i]disproportionate influence[/i] on what, exactly, gets counted as a "crime," how quickly police might respond, or [i]what[/i] taxes get paid to [i]whom.[/i] "The System" is corrupt, but it still exists, and may not [i]necessarily[/i] be beyond repair.

In some parts of the City, Corporations have begun to assume [i]some[/i] (not all) responsibilities that are, now, typically managed by city or local governments - the biggest example being the (ccasional) administration of a district's police force. There's no need to assume that [i]because[/i] Argos has taken over a police district that [i]automatically[/i] that district will become a gang of violent, heavily-armed thugs above the law - things in this world have not progressed to that point. Egregious, obvious abuse will result in at the very least publicity, and should the government in question find enough lawyers, suspension of the contract. That said, that kind of power (Police activity) accruing into the hands of an organization that may not see itself bound by the rules of government (A corporation), is something [i]else[/i] that is an easy path to corruption and serving only the highest bidder - and you can [i]absolutely[/i] assume that sort of thing happens in a thousand small ways, every day.

Areas outside of the City (Or any other "City") are typically sparsely-populated, with limited infrastructure and few of the services offered by governments or Corporations. The Interstate system is crumbling, and driving on that cracked and decaying network is getting more and more dangerous. Not "Mad Max" dangerous - though bandit groups do exist - but the roads are bad and service stations very rare. Interstate, and inter-City travel is handled by large, very fast, armored, and entirely-privately-owned heavy maglev railway systems, on which passage is fairly expensive. Air travel is also a [i]huge[/i] luxury item, and typically available only to the Corporate elite - many people will never leave the City they were born in. 

Hope that helps!