So I booted up the traffic system on Italy, and the first things that spawned were a Firwood Police Bluebuck, Detective Moonhawk, and a Bolide. After more runs of different traffic sets and switching maps, it appears that there seem to be two lists that the game pulls traffic from, one of traffic vehicles and one of police cars. Obviously, that leads to numerous situations in which traffic spawns vehicles that make no sense whatsoever for a map. There is a very simple solution to this issue, every official map (within reason, no gridmap, cliff, or template obviously) should have it's own pool of police cars and traffic cars. If a map is not one of these maps, the current system would be implemented in which it chooses completely random cars. Not a super complex suggestion, but one that would make the game far more immersive.
I would love to be able to pick and chose what vehicles the traffic spawns. Yes its nice that it spawns only street cars but the pigeon doesn't fit in Utah and neither does the air cooled compact car nor the JDM ibishu.
press escape or whatever you have the menu bound to, click AI, click on the traffic light icon, and then it will give you options
Not sure who's aware of this, but you can spawn cars via the menu to be exactly what you want, and then start the traffic. All cars except the one controlled by the player will be affected, not just ones spawned by the app.