State troopers, define:

Law enforcement officers have forums. I would ask your question in those forums as those LEOs live with that rule while truck drivers only see the random "trooper" or cop and in various states. Even if one of truck drivers here knew the answer dies he know the answer in EVERY state? Does a dozen guesses answer your question? Ask a state trooper.

 

In the upper midwest, it was Bear, as in, "Smokey the". I can say without reservation, most state troopers, when treated with respect, were always cordial. County Mounties, a bit less and local cops, the worst. Michigan troopers, for many years, used plain cruisers with one red gumball machine. They recently won the best looking cruiser, in some competition. Tell that to the trooper next time, "hey, nice looking cruiser",,,nah, just keep your big mouth shut!
Michigan State Police in tight race in best looking cruiser content

 

The word “state” is your clue. If they see a crime anyplace inside the border of the state they can start pursuing, detaining, or arresting you. In most places with thier own police coverage such as a small town or city the local police will assist or take controll of an investigation depending on the issue at hand. They in most cases are not assigned to patrol areas that have thier own police coverage as potrol areas eventually break down to cost.
So for instance the area where I live. We don’t have local police we voted against having them. We rely on the county sherif and state police on a per call basis. In this case they don’t patrol our side and back roads but you do randomly see them on the state roads that run threw on both the north and south side of our township. If there are a lot of complaints about speeding and other things for those roads you will see more of them.
To get a traffic citation out here on a township road you would have to be a total idiot and be doing stupid crap on a regular basis long enough for someone to call in a complaint and them to respond. Keep doing the same stupid stuff constantly and have many complaints provoking the township supervisors to request a patrol of the area or have an accident that requires a police officer be called or my favorite be dumb enough to do it while one of the officers is in transit to or from thier home in a police car. My neighbors son comes to mind on the last one.
Mileage of this will vary from state to state, township to township and city to city but the last determining factor will always break down to the cost in some way shape or form.

 

Paul, ANY sworn law enforcement officer can enforce State statue. What varies is the severity of the crime and the duty to act.

For example, you're probably going to get called a barney if you pull some soccer mom over for reckless driving out of your jurisdiction and off of dash/body cam. Easy conviction and common sense right?

You will be lauded a hero if while off duty you witness and stop a violent felony from taking place.

Every agency has a "patrol" area. That is their jurisdiction.

For example:
FBI = The United States - Jack of all trades and the true innovators and enforcers of the professional policing model nationwide
US Marshals = The United States but they specialize in the apprehension of violent felons
State Patrol = Generally the State
County Sheriff = The County they are in
Minneapolis = Whatever boundaries define your great city

 

Highway patrol starts their name with trooper.

They patrol the highways. It's rare to see them in the city with a car.

They do,.however, hang out for random truck inspections. Like the quarries or dump sites. Dot highway patrol.

 

Yes there is a lot more involved than I put forth, take it from one of the township supervisors who has to deal with the cost and contract for patrolling. But for the simplicity of driving as what I felt to be what a driver asking a question here would be asking about in most states what you need to pay attention to is that basic breakdown.

 

Varies by state by many have the following guidelines.

State Patrol. Traffic jurisdiction statewide on any roadway. Limited criminal enforcement to highways, state property and if requested by local jurisdiction as a backup unit.

State Police: Traffic jurisdiction statewide on any roadway. Criminal enforcement statewide.