The basic thought on this is that there would be some system of licenses, some automatic if you say work at CHEX for a set amount of time without an accident. Others requiring an application at the Hall and a test of proficiency. I'd say three levels would be appropriate.
First off you'd have a kind of provisional license, one not handed out explciitly by the hall or with restrictions, saying you can drive or pilot on gold or green, but with certain restrictions subject to the hall... If you apply at the hall for this it would be a case of "I need a skillsoft," and you'd fall in this category. You can drive, but only with a skillsoft, and if you're caught driving without that, you are subject to fines or vehicle modification to enforce licenses. Corporate people could fall in this category but the vast majority of it would be mixers who work at or in some cases worked at CHEX or Skyfox for a set amount of time without an accident. This would not permit driving on Green without being requested by a resident of Green.
Second off, you'd have a full class 1 personal license, this is one you'd have to apply for and provide proof of skill for. It wouldn't be automatically granted except to people who are vetted solidly to a corporation. And the process for application would be mostly automatic, it would allow driving on Green(As to get a license you need to be corporate in general or have massive connections.)
Class 2 Licenses would be permits to pilot or drive with passengers and would be a second application after a class one. Which would involve more RP to get. This would only be automatically granted to corporate members who's explicit job is flying, driving or other forms of locomotion for other players, and would only be granted otherwise with sufficient connections.
Some potential later additions to this might be a check of passengers in the vehicle to make sure you've got a corporate citizen inside before going to Green with your vehicle. With alerts being sent to Judge PC's if you don't.
What would this provide? A source of RP for judges. A boot to the neck for Mixers with vehicles who now have to jump through hoops to gain licenses or just take the levs. Complications and work for mechanic PC's both mix and topside. And a base to build off of for more enforced control of egress into and out of gold and more explicitly green.
License and registration, sir and/or ma'am?